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  • Memory Timings Explained W/ Suggested Timings & Memset VS. BIOS

    First of all the basics


    Rated Memory Timings


    • CAS (tCL) Timing: CAS stands for Column Address Strobe or Column Address Select. It controls the amount of time in cycles between sending a reading command and the time to act on it. From the beginning of the CAS to the end of the CAS is the latency. The lower the time of these in cycles, the higher the memory performance.
      e.g.: 4-4-4-12 The bold “4” is the CAS timing.
    • tRCD Timing: RAS to CAS Delay (Row Address Strobe/Select to Column Address Strobe/Select). Is the amount of time in cycles for issuing an active command and the read/write commands.
      e.g.: 4-4-4-12 The bold “4” is the tRCD timing.
    • tRP Timing: Row Precharge Time. This is the minimum time between active commands and the read/writes of the next bank on the memory module.
      e.g.: 4-4-4-12 The bold “4” is the tRP timing.
    • tRAS Timing: Min RAS Active Time. The amount of time between a row being activated by precharge and deactivated. A row cannot be deactivated until tRAS has completed. The lower this is, the faster the performance, but if it is set too low, it can cause data corruption by deactivating the row too soon.
      tRAS = tCL + tRCD + tRP (+/- 1) so that it gives everything enough time before closing the bank.

      e.g.: 4-4-4-12 The bold “12” is the tRAS timing.

    (The 4-4-4-12 figure is just an example for main memory timings.)

    These are the four timings that you would see when memory is being rated. It is in the order of CAS-tRCD-tRP-tRAS. The lower these timings, the higher the performance of the memory. Some motherboard manufacturers (DFI for example) list the timings in their bios CAS-tRCD-tRAS-tRP.


    Certain memories can take tighter (lower) timings at higher speeds. These are the more expensive memory modules out of the bunch. There are also other timings to consider in your BIOS. Not all boards will have options like these.

    Advanced Memory Timings

    • tRRD Timing: (Act to Act Delay) Row to Row Delay or RAS to RAS Delay. The amount of cycles that it takes to activate the next bank of memory. It is the opposite of tRAS. The lower the timing, the better the performance, but it can cause instability.
    • tWTR Timing: (Rank Write To Read Delay) Write to Read Delay. The amount of cycles required between a valid write command and the next read command. Lower is better performance, but can cause instability.
    • tWR Timing: (Write To Precharge Delay)Write Recovery Time. The amount of cycles that are required after a valid write operation and precharge. This is to insure that data is written properly.
    • tRFC Timing: (Refresh To Act Delay) Row Refresh Cycle Timing. This determines the amount of cycles to refresh a row on a memory bank. If this is set too short it can cause corruption of data and if it is too high, it will cause a loss in performance, but increased stability.
    • tRTP Timing: (Read To Precharge Delay) Number of clocks that are inserted between a read command to a row pre-charge command to the same rank.

      Below Values are not in ALL BIOS's (See Below link for a FULL List of Values)

    • tRTW/tRWT Timing: Read to Write Delay. When a write command is received, this is the amount of cycles for the command to be executed.
    • tRC Timing: Row Cycle Time. The minimum time in cycles it takes a row to complete a full cycle. This can be determined by; tRC = tRAS + tRP. If this is set too short it can cause corruption of data and if it is to high, it will cause a loss in performance, but increase stability.
    • tREF Timing: The amount of time it takes before a charge is refreshed so it does not lose its charge and corrupt. Measured in micro-seconds (┬Ásec).
    • tWCL Timing: Write CAS number. Write to whatever bank is open to be written too. Operates at a rate of 1T, but can be set to others. It does not seem to work with other settings than 1T on DDR. DDR2 is different though.
    • Command Rate: Also called CPC (Command Per Clock). The amount of time in cycles when the chip select is executed and the commands can be issued. The lower (1T) the faster the performance, but 2T is used to maintain system stability. On Intel based machines, 1T is always used where the number of banks per channel are limited to 4.
    • Static tREAD Value: (tRD) This setting is most commonly known as Performance Level or tRD this is the most effective chipset performance register available to adjustment. As FSB and memory speed are scaled/increased, tRD and Northbridge voltage will have to be increased to accommodate the additional data throughput. The idea when tweaking your system for the BEST performance is to run the tightest (Lowest) tRD possible at any given FSB or memory speed. See Below Link for more reading on this


    Full List of Most All BIOS Memory Values

    Some are covered here and some are not as they are not relevant to Most Gigabyte boards
    Tweakers.fr

    Conclusion

    CAS-tRCD-tRP-tRAS are the main timings that are of concern to most users.

    All of the other settings are only really changed when overclocking, or tweaking your timings. If you plan to stay at stock frequencies and timings, there is no real need to play with the other advanced memory settings.

    Ram Multiplier Calculator
    http://www.peakin.com/xbx2/calculato...fsb=320&mult=9


    MemSet VS. BIOS Settings (Download Linked Below)





    Suggested Settings for P35/P45 Boards

    Performance Enhance
    ________________ Standard

    CAS Latency Time________________ 4/5
    Dram RAS# to CAS# Delay_________ 4/5
    Dram RAS# Precharge Delay________4/5
    Precharge Delay (tRAS)___________ 12/15/18

    The above ranges will be dependent upon your ram spec which should be listed on the package or sticker of your ram

    The ranges below are meant to be used as stable stock timings that can be latter tested and lowered one by one with testing between each move.

    The timings x2 in ()'s below are to be tested last only for benchmark purposes.

    And just so everyone is clear on this the latter one being Static tRead Value May HARD FAIL for most all users and often cause a need to Clear CMOS if you attempt to use 5/6, but some will get it to work and it is worth the time and effort if you are into tweaking your ram to at least try it a few times. If you do decide to try it then please have the other subtimings loose when you first attempt it

    Memtest86+ is suggested for memory testing (Download Linked Below)

    ACT to ACT Delay (tRRD)________ 3-4
    Rank Write to READ Delay (tWTR)_______ (4-6) 9-11 (Note Actual Value set in BIOS Vs. What system Uses will be 7+)
    Write to Precharge Delay (tWR)________ 3-5 (Note Actual Value set in BIOS Vs. What system Uses will be 5+)
    Refresh to ACT Delay (tRFC)___________ 38-42 (2X1GB) 52-62+ (2x2GB)
    Read to Precharge Delay (tRTP)_________ 3-6 (Note Actual Value set in BIOS Vs. What system Uses will be 2+)
    Static tRead Value (tRD)______________ (5/6) 7-10 (800Mhz) 7-12 (1066Mhz)
    Static tRead Phase Adjust________ 1-31*

    * Pertaining to Static tRead Phase Adjust: Leave on Auto or Zero Or 1-31 (This Adjustment is uncontrolled and subtracts from the Static tRead Value at random times and is suggested to not be used unless you really know what you are doing. For more in depth read about this setting you can have a look here >>>
    AnandTech: The Gigabyte GA-X48T-DQ6 - Redefining the High End?

    Also Some in depth Static tRead Value (tRD) discussion here as well
    AnandTech: ASUS ROG Rampage Formula: Why we were wrong about the Intel X48
    Last edited by Lsdmeasap; 11-30-2010, 12:20 PM. Reason: Memset VS BIOS Additional explanations

  • #2
    Re: Memory Timings Explained W/ Suggested settings + Memset VS. BIOS

    MCH Voltages/tRFC (Refresh To Act Delay) & More Than 2 X 1GB of Memory

    When using 2 X 2 or more of Memory you will have to add more MCH Voltage. How much is up to the ram you are using, the board itself, and overall memory performance.

    Suggested MCH Voltage to add (Even for 2 X 1 GB) is +0.1V. When you start tweaking, Overclocking, or just plain using 2 X 2GB or more you will need to add More MCH Voltage. Amount will Vary but just moving up to +0.15V or +0.2V will usually do it for 2 X 2GB. More of course will need more.

    Trial and error is the only way to know for sure how much your board and ram will need, but +0.3 is almost never necessary. If you find yourself thinking your board needs this much please ask someone as it is most likely you have some other setting that is "Off" that is affecting your stability and making you think you need more.

    Refresh to Act Delay Or tRFC will have to also be adjusted when using more then 2 X 1GB of Memory. Normally a range between 52 and 62 will be fine for 2 X 2GB of ram, and with some fine tunning you can usually run at 48 or 50. More then 4GB will need more of course, but how much is again up to your Memory, Board and some patient testing.

    Memset (LIVE Memory Tweaker and Value Checker)

    MemSet is a tweaker which allow to change memory timings under Windows.
    You can read principal and secondary timings, and eventually change these timings values. This is useful in checking values you set in the BIOS against what you get in windows, or to see what AUTO is giving you as a setting.

    You can change ANY subtimings LIVE within windows and apply it, but do not save or set to run at startup. Make any changes you plan to keep in the BIOS and test them respectively. You cannot change Main timings with this program. And of course, YES you can crash or freeze your system changing values LIVE, if this happens to you do not worry simply shut down your PC and restart it all will be fine

    Memset Live Memory Tweaker Homepage

    Memset V. 4.0

    -Use WinRing0 driver.
    -Interface is the same for all chipsets/CPUs.
    -Add support for Intel Core i7 CPU (Reading only).
    -Loading time was improved.
    -Improve frequency reading on Core i7.
    -Improved reading SPD info on DDR2 & DDR3.
    -Fixe frequency reading on some Core 2 Duo CPU.

    Memset V. 4.0 Download


    Memtest86+ (Memory Testing)

    Memtest86+ - Advanced Memory Diagnostic Tool Download

    When doing basic tests on new ram or just for general testing purposes you should let the test run on it's own for a few hours up to 24 if you have the time and don't mind.

    When you are tweaking timings and just need some quick answers you can quickly see if your recent changes have made your ram unstable by choosing certain tests. Some say their own set of test #'s to use and they may differ from my own, so if you see someone else suggesting test #'s they that would be fine as well to, it is up to you.

    What test #'s I use for basic speed testing to see if recent changes are causing errors quickly are #'s 2 & 5. I run test #2 for about 10 minutes and if I see no errors I will then run test #5 for a hour or so. If no errors are found then your changes are likely ok for the time being. Longer tests will let you know for sure though, but like I said here we are speed testing while doing a little bit of tweaking. If it is going to fail you think and are not so sure let #5 run for a while. It will fail on #5 if it is going to fail.

    Below are Some BIOS examples, Sorry for the Resolutions I did not take them myself.

    GA-P35 BIOS Example



    GA-P45 BIOS Example




    **SIDENOTE**

    To run tests by number, you do this >>>
    1. First press C

    2. then 1

    3. then 3

    4. and finally select the test that you want to run

    5. press Enter

    6. and then 0 to get it running

    I mention this because you may often see myself or someone else suggest only running certain tests by #'s at certain points. Which is what I do when fine tunning subtimings, I will run Test #2 and Test #5 for a variable amount of time between changing settings one a a time. After many moves though, please be sure to run some full tests for several hours


    **NOTE**

    On Some Gigabyte Mother boards you will need to use a hotkey to see all BIOS settings. These are either older boards or boards that have not updated BIOS's recently.

    The Hotkey is Control + F1 (Ctrl + F1). You will need to push this Hotkey Combination on the MAIN or Front Page of the BIOS, the screen will then very quickly flash. After that you may go into the M.I.T section and ALL hidden settings will be shown. This will also enable hidden settings to be shown in ALL Sections of the BIOS not just the M.I.T. Section.


    I would like to thank Merman our fellow board member for him suggesting this thread to me and I hope you all find it to be of at least a little help. If nothing else you will at least have more knowledge now then what you did before about Ram since you took the time to read this over
    Last edited by Lsdmeasap; 01-13-2009, 03:56 PM.

    Comment


    • #3
      Re: Memory Timings Explained W/ Suggested Timings & Memset VS. BIOS

      Wow! I didn't expect so much information. Excellent work.

      I really like the settings numbered in MemSet. Now they should be referenced to recommendations. The first four settings are easy to see but after that it gets confusing.

      Suggested Settings for P35/P45 Boards

      (1) CAS Latency Time________________ 4/5
      (2) Dram RAS# to CAS# Delay_________ 4/5
      (4) Dram RAS# Precharge Delay________4/5
      (5) Precharge Delay (tRAS)___________ 12/15/18

      Maybe not so easy, did I get them right??? Hey I did get them right as I just read the NotePad. Duh. Lots of good info here and I may be reading too fast.

      At first I didn't realize the second half recommendations are listed in the same order as the BIOS. Maybe a note that the second half recommendations are listed in BIOS order or re-arrange some of the notes below the BIOS settings???

      I think people need to see at a glance and/or told that this is the BIOS setup Memory Options and reminded that for some boards Control F1 has to be entered at the main bios menu to see these options and value settings.

      Maybe an image would help???



      I also was going to suggest the Anandtech reference but you already did.

      Thanks for the credit.

      Comment


      • #4
        Re: Memory Timings Explained W/ Suggested Timings & Memset VS. BIOS

        I was just reading this thread:

        Re: GA-EP35-DS3L vcore problem after Standby

        --------------------------------------------------------------------------------

        Well yes, and no. 2.1 is likely for sure all your ram needs, but with the proper timings as well. If you dont want to mess with tweaking it for a while then I would suggest you use 2.2 and please do you ram a favor and put a fan over it.

        You will need a RMA soon for sure with 2.2, that is the MAX warrantied voltage, not what is needed to run stable.

        I would suggest this for 4x1GB >>>
        Performance Enhance = [Standard]

        CAS Latency Time________________ 4
        Dram RAS# to CAS# Delay_________ 4
        Dram RAS# Precharge Delay_______4
        Precharge Delay (tRAS)__________ 12

        Start with the higher settings, moving later ONE AT A TIME lower and test after each move

        ACT to ACT Delay (tRRD)_________ 3-4
        Rank Write to READ Delay________ 9-11
        Write to Precharge Delay_________ 3-5
        Refresh to ACT Delay______________ 42-52
        Read to Precharge Delay__________ 3-6
        Static tRead Value_______________ 7-10
        Static tRead Phase Adjust________ Auto << Leave ALWAYS

        System Voltage Control____ [Manual]
        DDR2 OverVoltage Control__ [+0.3V]
        PCI-E OverVoltage Control_ [Normal]
        FSB OverVoltage Control___ [+0.1V]
        (G)MCH OverVoltage Control [+0.1V - 0.15V]
        Do you think :

        1. Performance Enhance setting should be listed in this guide too???

        2. Does Refresh to ACT Delay settings depend upon memory capacity??? 2,4 or 8gigs.

        3. Should System Voltage Controls concerning memory also be included in this guide???

        Comment


        • #5
          Re: Memory Timings Explained W/ Suggested Timings &amp; Memset VS. BIOS

          I see the P45 Advanced Timing Control is different. The timing options order is the same without some of the nomenclature but Channel A and B have more adjustments. ???


          Comment


          • #6
            Re: Memory Timings Explained W/ Suggested Timings &amp; Memset VS. BIOS

            Damn ya! Na, Just kidding

            Thanks for the great input, I thought I may not need to go that deep yet!

            I will work on your suggestions over the weekend.

            As for your Refresh to Act question, YES it is absolutely dependent on how many GB you have installed and really what you will end up with may be less then I stated after tweaking. And that direct thread I believe I just gave that user those numbers to try as he in my opinion was having issues with incompatible ram so I was seeing if I could help him get anywhere with it. (*See my not below concerning this)

            52-62 is a good starting point for 2x2GB, some will get down to 48-50 with proper testing. 4X1GB is about the same but may end up a little higher after tweaking and testing all depending on the Ram's bandwidth and quality

            * I was going to also add in my suggestions for and against ram brands but I thought it may be too much for now. And most people, even if they do ask, do not want to hear that there 4-8GB of brand new ram is not on the QVL or in my opinion is incompatible and end up trying to blame the board or something else when they should be doing a RMA soon as possible

            I appreciate your suggestion and I will work on getting them added in this weekend for sure.

            I do not have X38/X48 Or P45 which have some of the more advanced options to post my own images, if you get time could you possibly send me full size images of the MIT section of a P45 BIOS? If so be sure you include the advanced memory page where you would hit enter to see. If not I am sure I can find some online.

            Thanks again for all your suggestions, and Ohh yeah I will also add in voltages this weekend as well

            Comment


            • #7
              Re: Memory Timings Explained W/ Suggested Timings &amp; Memset VS. BIOS

              Originally posted by Lsdmeasap View Post
              I do not have X38/X48 Or P45 which have some of the more advanced options to post my own images, if you get time could you possibly send me full size images of the MIT section of a P45 BIOS? If so be sure you include the advanced memory page where you would hit enter to see. If not I am sure I can find some online.
              I have a GA-P35-DS3L but will look on line for these images to save you some time. What I find I will send by PM.

              Thanks for your efforts.

              Comment


              • #8
                Re: Memory Timings Explained W/ Suggested Timings &amp; Memset VS. BIOS

                yeah, wow, answered my questions before i had to ask.

                id be interested to hear your recommendations for ram brands.. ill be looking to build myself another computer, and i'd like to stick with a gigabyte mobo because thats what im using now, and it was easy for me to overclock. also 8gb of ram (vista x64 kicks ass ).

                thanks for all your efforts lsd
                Q9650 E0 1.2 VID 445x9 4005mhz 1.23v
                GIGABYTE EP45-UD3R
                Mushkin 2x2gb 1066 DDR2 5-5-5-15 2.1v
                Lapped TRUE w/ 110cfm Panaflo (shrouded)
                Corsair HX620 Modular
                CoolerMaster 690 Case
                EVGA 9800GTX+

                Comment


                • #9
                  Re: Memory Timings Explained W/ Suggested Timings &amp; Memset VS. BIOS

                  Anytime, I plan to try to find time to update this a bit more tonight or soon as I can.
                  Last edited by Lsdmeasap; 11-19-2008, 06:38 PM.

                  Comment


                  • #10
                    Re: Memory Timings Explained W/ Suggested Timings &amp; Memset VS. BIOS

                    Kingston ram i've found works well (i've built a few computers with gigabyte boards and kingston ram with no probs).
                    Last edited by Lsdmeasap; 11-19-2008, 06:38 PM.

                    Comment


                    • #11
                      Re: Memory Timings Explained W/ Suggested Timings &amp; Memset VS. BIOS

                      I have been tweaking my memory and thought I would mention some of my experiences.

                      My system:
                      GA-P35-DS3L
                      E8400 at 3GHz and 3.6GHz
                      Corsair Memory CM2X1024-6400C4 version 6.2
                      PSC 128Mx8 memory chips
                      DDR2 at 400MHz
                      2-1gig sticks rated at 444-12 at 2.1v
                      I have been able to run it at 1.8v even at 960MHz
                      SPD: 555-18, tRC 22, 1.8v at 400MHz per CPU-Z
                      Everest adds:
                      tRRD 3
                      tWTR 3
                      tWR 6
                      tRFC 42
                      tRTP 3

                      This ram really likes the SPD specs. Not surprising I suppose. :)

                      I found that most of the settings stay the same from 3GHz to 3.6GHz. Except for the main settings of 444-12 to 555-18 and tWTR and tWR have a mind of their own.

                      WTR and WR will crash Vista 32 when trying recommended settings and MemSet will show different settings than set in the BIOS. ???

                      I suppose more important tRD and tRFC seem to be the most important settings or show the most improvement other than CPU speed.

                      All these settings are at Memory multiplier of 2.4. At 3.6GHz I tried changing to 2.0 and Vista crashed hard. That supprised me. The memory was running stable at 960MHz but reducing it to 800MHz would crash the system???

                      Settings:

                      .......................3GHz..........3.6GHz....... ...Recommended.....MemSet diff

                      Perf. Enhanced Turbo........Standard

                      Memory Multiplier Auto.........Auto
                      Frequency..........800...........960

                      Standard Timing 444-12.......555-18

                      Advanced Timing:
                      tRRD...................3................3......... ............3-4
                      tWTR..................3................3.......... ...........9-11.............10..&11
                      tWR....................6................6......... ............3-5...............13..&14
                      tRFC..................42...............42......... ...........38-42
                      tRTP...................3.................3........ .............3-6...............5..&5
                      tRD.....................6.................6....... ..............7-10
                      Phase Adj.... left on Auto.

                      Any comment or suggestions???
                      Last edited by Merman; 08-16-2008, 07:55 PM.

                      Comment


                      • #12
                        Re: Memory Timings Explained W/ Suggested Timings &amp; Memset VS. BIOS

                        First off, sorry man I have been so busy I have yet to have time add in things we have discussed. But I have been writing them up and collecting other info and doing some in depth reading about skew control as well. I will get it done trust me.

                        Sorry I forgot to add a similar note to tWR that I added to tWTR, they both will always be different then set in the BIOS, I will add the other note in. I think it is by 8-9+ depending for tWR. The thing I guess I need to also address is between chipsets sometimes tWTR needs to be set to whatever in the BIOS that equals 11-12 in Memset, which is often 4-5. tWR is a bit different on how things should be set depending on a few other factors and what things are set on.

                        When you say crash vista when trying "Recommended" settings, who's recommended settings are you referring to?

                        Yes, tRD is the single most thing that affects Memory Bandwidth that is why it is often called the Performance Level.

                        As for your crashing, what settings in the BIOS did you have that make 800 crash on you? If it was tRD of 6 then that is likely the setting that caused it, it may have worked for you at 2.4 multi because of a strap being used or not.

                        I guess I would need a better table of what you used at each to understand, you saying things about the SPD have me unclear what you used even with your table. Since the SPD is not used in Intel boards fully, nor does the SPD contain all settings info I am not sure if you chose SPD from memset or what you were seeing in AUTO on the left in the BIOS (Which would be incorrect, often change, and ONLY be used at that specific time in the BIOS)

                        Yes AUTO does try to read SPD info in a Intel Board and sometimes gets part of it correct. Intel has been working on getting this better like Nvidia Chipsets EPP and how they read them. They have implemented XMP, which is similar.

                        SPD is programmed in memory to go above JEDEC standards and is made to be read by EPP programming, which is why AUTO often in not correct it getting these settings

                        Comment


                        • #13
                          Re: Memory Timings Explained W/ Suggested Timings &amp; Memset VS. BIOS

                          Originally posted by Lsdmeasap View Post
                          First off, sorry man I have been so busy I have yet to have time add in things we have discussed. But I have been writing them up and collecting other info and doing some in depth reading about skew control as well. I will get it done trust me.
                          No need to apologize. You answer all the questions on this board and helping everyone should be more than enough. I thought this guide would help ease your load and give everyone a solid easy to find reference. With that in mind I see no reason to rush.

                          Originally posted by Lsdmeasap View Post
                          Sorry I forgot to add a similar note to tWR that I added to tWTR, they both will always be different then set in the BIOS, I will add the other note in. I think it is by 8-9+ depending for tWR. The thing I guess I need to also address is between chipsets sometimes tWTR needs to be set to whatever in the BIOS that equals 11-12 in Memset, which is often 4-5. tWR is a bit different on how things should be set depending on a few other factors and what things are set on.
                          Interesting. I see I'm just getting my feet wet.

                          Originally posted by Lsdmeasap View Post
                          When you say crash vista when trying "Recommended" settings, who's recommended settings are you referring to?
                          The recommended settings in this guide. Its basically tWR as when my settings are lower than recommended I don't try going lower. My tWR setting is 6 and going lower hard crashed Vista. By hard crash I mean Vista stopped giving a warning that it stopped so no damage is done.

                          Originally posted by Lsdmeasap View Post
                          Yes, tRD is the single most thing that affects Memory Bandwidth that is why it is often called the Performance Level.

                          As for your crashing, what settings in the BIOS did you have that make 800 crash on you? If it was tRD of 6 then that is likely the setting that caused it, it may have worked for you at 2.4 multi because of a strap being used or not.
                          That doesn't make sense to me. The ram was running stable at 960MHz, CPU at 3.6GHz with tRD at 6 with the multiplier on Auto. I was thinking of upping the CPU frequency but wanted to set memory frequency to 800MHz first. I changed the mulitplier from Auto to 2.0. The system rebooted twice and reset the BIOS to stock settings. Doesn't make sense to me maybe I made some other mistake. ???

                          Re-reading your reply mentioning the "strap" my BIOS has on the right markings to show which multiplier coincides with which strap. At least that is my uderstanding. ??? Seems I have to take another look at this and fully understand this section of the F8 final bios for the P35-DS3L.

                          Though for 400MHz memory to run at 960MHz with a 400MHz FSB, its 400*2.4=960MHz. So 400*2=800MHz and stock 333*2.4=800MHz Am I missing something here???

                          Originally posted by Lsdmeasap View Post
                          I guess I would need a better table of what you used at each to understand, you saying things about the SPD have me unclear what you used even with your table. Since the SPD is not used in Intel boards fully, nor does the SPD contain all settings info I am not sure if you chose SPD from memset or what you were seeing in AUTO on the left in the BIOS (Which would be incorrect, often change, and ONLY be used at that specific time in the BIOS)
                          Sorry I thought my post was clear. The SPD settings were taken from CPU-Z and Everest. See the first paragrph of my last post listing my system. My understanding is these programs are reading the SPD info stored in the memory. In CPU-Z the info is under SPD. In Everest the info is under Motherboard/SPD/Memory timings.

                          My table of Settings shows BIOS settings for 3 and 3.6GHz, the guide's recommended settings, and the MemSet column showing any different settings than what was set in BIOS. As you explained tWTR and tWR should report a different setting than what was set in BIOS. Though tRTP also shows a small different setting.

                          Originally posted by Lsdmeasap View Post
                          Yes AUTO does try to read SPD info in a Intel Board and sometimes gets part of it correct. Intel has been working on getting this better like Nvidia Chipsets EPP and how they read them. They have implemented XMP, which is similar.

                          SPD is programmed in memory to go above JEDEC standards and is made to be read by EPP programming, which is why AUTO often in not correct it getting these settings
                          The only Auto setting used was the Memory Multiplier. I know that 2.4 was used because it shows the memory frequency in the BIOS and CPU-Z confirmed it though it reports the setting as 5:6. Though the P-35-DS3L did read the memory's SPD very accurately.

                          Comment


                          • #14
                            Re: Memory Timings Explained W/ Suggested Timings &amp; Memset VS. BIOS

                            The recommended settings in this guide. Its basically tWR as when my settings are lower than recommended I don't try going lower. My tWR setting is 6 and going lower hard crashed Vista. By hard crash I mean Vista stopped giving a warning that it stopped so no damage is done.
                            This is likely only because you are using tRD of 6, which as you see I suggested against for a few reasons. Mostly though because the guide was Meant for "General Getting your board up and running smoothly" and not a full "Tweaking" Guide. Which would be using 6 possibly on some boards depending on the quality and bandwidth of the ram at hand, along with a different set of most other settings being optimal

                            Re-reading your reply mentioning the "strap" my BIOS has on the right markings to show which multiplier coincides with which strap. At least that is my uderstanding. ??? Seems I have to take another look at this and fully understand this section of the F8 final bios for the P35-DS3L.

                            Though for 400MHz memory to run at 960MHz with a 400MHz FSB, its 400*2.4=960MHz. So 400*2=800MHz and stock 333*2.4=800MHz Am I missing something here???
                            Well there is a internal 333 and 400 Strap for the NB weather it is shown as a Option or not in your Memory Multi choices. And again tRD of 6 with either strap may or may not work at any freq, depending on the other settings

                            Sorry I thought my post was clear. The SPD settings were taken from CPU-Z and Everest. See the first paragrph of my last post listing my system. My understanding is these programs are reading the SPD info stored in the memory. In CPU-Z the info is under SPD. In Everest the info is under Motherboard/SPD/Memory timings.

                            My table of Settings shows BIOS settings for 3 and 3.6GHz, the guide's recommended settings, and the MemSet column showing any different settings than what was set in BIOS. As you explained tWTR and tWR should report a different setting than what was set in BIOS. Though tRTP also shows a small different setting.
                            Ahh, Ok I see what you mean now, I thought maybe you was saying the "AUTO" or left in the BIOS was what you thought SPD setup was, You can also use the SPD button in Memset (Just incase you didnt see it)

                            tRTP should be as set in the BIOS, does it always vary for you? If so, that could possibly be part of the factors that make the ram not fully compatible in my book with GA boards. I have often wondered what all those factors are but will likely never know

                            The only Auto setting used was the Memory Multiplier. I know that 2.4 was used because it shows the memory frequency in the BIOS and CPU-Z confirmed it though it reports the setting as 5:6. Though the P-35-DS3L did read the memory's SPD very accurately.
                            Sorry, what I meant to better say was intel P35 Chipsets do not accurately "Use" the SPD info for AUTO settings properly.

                            And also keep in mind any SPD setting you see is for use at 800MHz speeds. You will have better luck and performance with a tRD of 7 with tighter other timings Vs. tRD of 6 with others being loose

                            But in the end, it all adds up to the memory's compatibility with the board, Chipset Performance and heat, and the actual Ram quality or bandwidth it provides.

                            And of course what voltages are being used in the NB and Ram, and at what strap/FSb is being used. I could provide you with a Very indepth reading on Straps if you would like

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                            • #15
                              Re: Memory Timings Explained W/ Suggested Timings &amp; Memset VS. BIOS

                              Originally posted by Lsdmeasap View Post

                              tRTP should be as set in the BIOS, does it always vary for you? If so, that could possibly be part of the factors that make the ram not fully compatible in my book with GA boards. I have often wondered what all those factors are but will likely never know
                              tRTP was always different than the BIOS settings even with tRD set at 7.

                              Originally posted by Lsdmeasap View Post
                              And also keep in mind any SPD setting you see is for use at 800MHz speeds. You will have better luck and performance with a tRD of 7 with tighter other timings Vs. tRD of 6 with others being loose
                              All memory settings were set to Auto to overclock the CPU to 3.6GHz. Then I started tweaking the memory settings. tRD was set at 7 by the Auto BIOS settings and the last setting changed because I didn't think it would run at 6. Other than the overclock this setting did the most to improve memory benchmarks to the tune of 500MB in Everest Memory Read. It also set the lowest latency of 59.4. Since 6 worked to my surprise I tried 5 but the system locked up. No major crash like some of the other settings.

                              Originally posted by Lsdmeasap View Post
                              But in the end, it all adds up to the memory's compatibility with the board, Chipset Performance and heat, and the actual Ram quality or bandwidth it provides.

                              And of course what voltages are being used in the NB and Ram, and at what strap/FSb is being used. I could provide you with a Very indepth reading on Straps if you would like
                              I understand. I suppose I could tweak this memory even more as it is running at stock voltage of 1.872v as is the FSB and MCH. But since it is running so well as is I may not try for more. I am also tired of all the rebooting and some hard crashes while reaching the limits.

                              Is this the article you were thinking about linking??? If not please do give the link.

                              AnandTech: ASUS ROG Rampage Formula: Why we were wrong about the Intel X48

                              This one about tRD and memory tuning is also good and I will be re-reading both. I find as I get more experience I understand the concepts better and the articles are so technical I absorb more when reading them again. I suppose that is just studying and learning in general for all us non geniuses.

                              AnandTech: Overclocking Intel's New 45nm QX9650: The Rules Have Changed

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