GA-M68M-S2 RAM voltage

[jpChris]

Hi all,

I just purchased a Gigabyte MoBo (GA-M68M-S2 rev. 1.0) and CPU (AMD Athlon II, X2 245, socket AM3) combo.

I'm trying to find out whether Kingston HyperX memory will work. Here's my confusion: In the manual it says DDR2 1066 support; but it says the voltage is 1.8 volts. However, the Kingston RAM is 2.2 volts.

Can I use the Kingston (KHX8500D2K2/2G)(2-1GB sticks) RAM and get 1066 out of it?

Price is important — not because I'm cheap — but because I don't have any, and this RAM fit's my budget.

The question is: Even though this memory fits my budget, will it fit my MoBo and give me 1066 performance?

[profJim]

Re: GA-M68M-S2 RAM voltage

1.8 volts is the default setting for DDR2 memory.
At 1066 speeds, you will probably need to set 2.0 - 2.1 volts, possibly more if the memory is rated at somewhat higher voltages.

Check the Kingston website and see if they have an online memory configuration/recommendation for your motherboard.
If in doubt, call or email Kingston tech support for their recommendations.

Keep in mind that running DDR2 memory at 800MHz with tighter memory timings (4-4-4-12) will give you virtually the same performance as 1066MHz with 5-5-5-15 timings.

The Gigabyte QVL for your GA-M68-S2 lists several Kingston modules, but has the following disclaimer:
Note: Due to AMD AM3/AM2+ CPU limitation, memory module DDR2 1066 or above speed is only supported by 1 dimm per channel.

Keep in mind that the QVL memory list only includes memory kits that they have tested with your mobo. There are many kits that will work, but you need to confirm that the memory manufacturer guarantees that a specific model of their memory will work with your mobo.

Good Luck!

**edit** you might do better with 800MHz 4-4-4-12 memory that can probably be overclocked to 900MHz (and possibly a bit higher).
I'm not familiar with AMD setups. Check the internet for any memory reviews or posts that include your cpu/mobo combination.

[jpChris]

Re: GA-M68M-S2 RAM voltage

Hi profJim,

At 1066 speeds, you will probably need to set 2.0 - 2.1 volts . . .

That's what I'm trying to find out: Can I set the voltage to higher than 1.8v? And if so, what's the maximum I can set it to? Even Taiwan doesn't know!

In the M.I.T. is a setting for the Memory Clock that can be adjusted to X5.33 to get 1066. And the Cas, Ras, Row, can be set to 3T~T6-T7; and the MinRas to 5T~18T.

Keep in mind that running DDR2 memory at 800MHz with tighter memory timings (4-4-4-12) will give you virtually the same performance as 1066MHz with 5-5-5-15 timings.

Note: Due to AMD AM3/AM2+ CPU limitation, memory module DDR2 1066 or above speed is only supported by 1 dimm per channel.

I checked the architecture of the AM3 and it will support up to 21GB of DDR3 or 17GB of DDR2. And as I'm getting two sticks of RAM to take advantage of the Dual Channel capabilities, how could I get more than one DIMM per channel? Or am I reading you wrong?

[profJim]

Re: GA-M68M-S2 RAM voltage

As far as I can tell, your mobo does NOT allow you to change and voltage settings in the bios.
It appears that only 1.8 volts is supported.
Its best not to exceed the memory manufacturer's maximum rated voltage if you want your memory to last. If your mobo only supports memory voltage at 1.8 volts, that rules out 1066 memory that needs higher voltages.

As I said earlier, 800MHz memory that runs with 4-4-4-12 memory timings will have real world performance that is similar to 1066 memory with 5-5-5-15 timings.
There are few games or applications that will take advantage of the increased memory bandwidth that is available with 1066 memory with DDR2 setups.

Your mobo is a basic unit that does not appear to support overclocking.
800MHz memory with 4-4-4-12 timings is probably too expensive for your budget.

Several notes from the GB website Specifications page for your mobo:

• * If you install AMD AM3/ AM2+ CPU on AM2 motherboard, the system bus speed will downgrade from HT3.0 (5200MT/s) to HT1.0 (2000 MT/s) spec; however, the frequency of AM3/ AM2+ CPU will not be impacted. Please refer "CPU Support List" for more information.
• * DDR2 1066 is supported with combination of AM3/ AM2+ processors and qualified memory modules, please refer "Memory Support List" for detail memory support information.

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1. 2 x 1.8V DDR2 DIMM sockets supporting up to 8GB of system memory (Note 1)
2. Dual channel memory architecture.
3. Support for DDR2 1066/800/667 MHz memory modules

(Note 1) Due to Windows Vista/XP 32-bit operating system limitation, when more than 4 GB of physical memory is installed, the actual memory size displayed will be less than 4 GB.

You might want to follow the Ga-m68m-s2p corsair memory stick issue thread.

[artdrivers]

Re: GA-M68M-S2 RAM voltage

ProfJim is offering good advice. Stay to 800Mhz or 900Mhz @1.8v with tighter timings I notice no real gain between 800Mhz with tight timings and 1066Mhz with higher voltage and looser timings.

Below is a pdf of your motherboard manual. http://download.gigabyte.ru/manual/m...-m68m-s2_e.pdf

You may want to test that memory well with memtest86+ 2.11 or 4.0http://www.memtest.org/

You may want to flash the latest bios for your motherboard
GA-M68M-S2 (rev. 1.0) - GIGABYTE - Support&Download - Motherboard - BIOS

[profJim]

Re: GA-M68M-S2 RAM voltage

@artdrivers
Thanks for your suggestions.
Right now bios version F1 is the only available version for his mobo.
Memtest86+ current version is 4.0.
It sounds like the OP is waiting for confirmation that the Kingston 1066 memory will work with his mobo before he buys it.

The M68M mobo's don't appear to have any voltage adjustments, so I doubt that 1066 memory will work unless he finds a kit that runs 1066MHz at 1.8 volts.

[jpChris]

Re: GA-M68M-S2 RAM voltage

Hi guys,

Sorry for the delay in responding, but I was waiting for confirmation from Taiwan before I did anything.

Taiwan tried a couple of sticks of the Kingston HyperX (KHX8500D2) @ 2.2 volts, set the Clock to x5.33, and got 1066. The Timing of 5-5-5-15 is "standard", but it will only run at 800MHz unless the Clock is set.

Also, Prof, your "tag" says to Load Optimized Defaults: Is that what I should do first, reboot and then tweak?

Thanks for your input, I appreciate it.

[artdrivers]

Re: GA-M68M-S2 RAM voltage

Hi profJim I noticed an F2 bios on a GA-M68M-S2 here---->
GA-M68M-S2 (rev. 1.0) - GIGABYTE - Support&Download - Motherboard - BIOS
jpChris
My Kingston memory will stress test without errors @ 1.8v @ 800Mhz. On mine in bios when I set the voltage to auto the memory voltage is @ 1.95v, but when I set it to manual and do not increase voltage it is @1.84v. I run prime95 @ 1.84v @800Mhz 5-5-5-15 for 12 hours without errors. I thought 12 hours was enough. I am using 4x1GB KHX8500D2K2/2GN. I tried 4x1gb KHX8500D2K2/2G and had to send it back. Although it could have been defective memory. I prefer the SLI compatable over KHX8500D2K2/2G. I beleive it will run at a lower voltage and obtain the 1066Mhz, but 1.8v@1066 is a little low for Prime95 stress test. The test failed at 1.95v. I had to set it to +3 which was 2.16v @ 1066Mhz with looser timings. I prefer the cooler 1.84v@800Mhz@5-5-5-15.
I think that profJim is correct in suggesting finding a kit of DDR-2 [email protected], or going to 800Mhz with tighter timings.
This info may or may not be beneficial to your final decision. I thought I would post it anyway.

[profJim]

Re: GA-M68M-S2 RAM voltage

Maybe I missed something, but I didn't see any memory voltage adjustments available in your motherboard manual.
This setting is usually called DRAM Voltage and is usually found the the bios MIT section, sometimes in a sub-menu.

Here's what I do with any new setup:

1. Install only 1 memory module in slot #1
2. Boot into the bios
3. load optimized bios default settings
4. save settings and exit
5. boot into bios again
6. press [ctrl]+F1 from the main bios screen, this will "un-hide" additional bios settings
7. make any needed bios changes in all bios screens
8. save your bios settings as a saved bios profile (if your system supports this feature)
9. save settings and exit
10. turn your system off
11. turn off the psu power, press and hold the font panel on/off switch for 10 seconds
12. install your second memory module
13. re-boot your system and pray

note: Never add or remove any hardware until you have powered off your system AND turned off your power supply using the on/off switch on the power supply.

Glad to have helped you out, good luck with your new system!
Let us know how it works out.

@artdrivers
Thanks for the bios update information. When I posted yesterday, F1 was the only available bios version.
Correct me if I'm wrong, but I don't see where there are any voltage adjustments available with his mobo.
There are many memory tweaks available, but unless his bios will read the memory SPD and "see" that his memory can run at 1066 speeds with higher voltage, I don't know if the bios will auto adjust the dram voltage higher than the standard 1.8 volts.
As stated earlier, his performance at 800MHz with proper memory timings should work just fine.