Corsair RAM tighter timings?

[earthdog]

Hi All!

with 21x191 i get 1528 for my RAM and default timings...and 1.65v

I am considering changing to 23x174 ..

This means i will get 1392 for my RAM....

Does this mean that i can compensate for freq loss by tightening the timings?

and if so where i go from the default 7-8-7-20?

My RAM is Corsair 1600Mhz 7-8-7-20 6GB

Thanks

Elias

[Chike]

Re: Corsair RAM tighter timings?

Does this mean that i can compensate for freq loss by tightening the timings?

Yes. Timings as you can guess are given in time (all but one, CAS). e.g. when left auto you will notice BIOS scales them automatically.

To make things short, devide the new frequency by a known frequency, in this case 1392 by 1600 = 0.87, now mulriply this value by the known timings and you get the new timings. If they are not far above the rounded down value it may work, otherwise you may need to use one value higher.
6-7-6-18 might work with current voltage.

[earthdog]

Re: Corsair RAM tighter timings?

The kind of answer i was looking for..

Thanks a lot...!!!

[Psycho101]

Re: Corsair RAM tighter timings?

This is certainly not a definite yes answer. Even if you are running your RAM at a lower speed, ther is no guarantee you can tighten the primary timings. I know thi sbecause I have a 4GB kit of the exact same Corsair RAM (7-8-7-20 PSC). Even at 1250 they will not run at CAS6 and the tightest I have had them running at that speed is 7-7-6-18 without either a BSOD or getting a corrupted OS.

Using a mathematical formula to tell you if you can tighten timings is pretty hit and miss and IMO not valid for every set of modules. The primary factor is quality of the RAM, not the numbers spat out by a formula. Corsair XMS lines of RAM are notoriously tightly binned and IMO not the best of the bunch by a long shot.

Having said that, you may be able to tighten the timings, as like I say, it depends entirely on the modules you have as well as on pure luck that yours will run tighter.

Try lowering values one at a time too. Merely punching in an arbitrary value like 6-7-6-18 is too much too soon. Change the CAS timing down one value FIRST, then see if you can boot, then if the system is stable. If you get a boot failure or fail LinX, you know *almost* certainly that the RAM will not tolerate a drop in CAS latency.

If a drop in CAS fails, then by all means move to the next value and try dropping that, and so on. Do note that those PSC modules are particularly sensitive to tRCD which is the second primary timing value or the 8 in your 7-8-7-20 modules. Some PSC is more sensitive to tRCD values than it is to CAS values and performance increases more pronounced with these types of PSC when it's lowered, even out stripping the impact of CAS.

I also noticed the GTX 580 in your sig so I assume you play games quite a bit. IMO for gaming you really want to be sticking to as high a Bclk as you can, with as high an uncore multi as possible, IF that means that your uncore will be running as fast as it possibly can while you maintain your desired CPU speed. Uncore speed has a strong effect on gaming performance.

[earthdog]

Re: Corsair RAM tighter timings?

yeap i thought that luck hazs to do something woth this one also....

so during the past hours i have tried an dsuccedded in overclocking to 4.00ghz with 23x174 @ 1.312vcore (1.280 cpu-s) level1 llc 1.35qpi AND 6-7-6-19 timings in RAM

i have just comepleted an one hour occt test with temps not above 73....

I would like to succeed in 21x191 but it goes up to 78 temp max and it crashes in 35 mins....this probably mean that i should raise vcore thus more temp...i dont know, i havent decided yet..

I ll try to finilize with this setup and my memory at 6-7-6-19 and we will see..

And as far as Gaming is concerned..I do game BUT i dont consider the app to be a game because it is old and bad written and cpu oriented..

I mostly build the rig for MS FSX...For other games i dont care if i have to run them a little bit with less options in details....:))))

Thanks for the long answer mate...

[Psycho101]

Re: Corsair RAM tighter timings?

Sounds good so far :)

Ye, FSX is very CPU bound, especially with lots of air traffic turned on etc.

With your setup and GPU don't worry about having to turn down any detail settings on other games, you will be fine, unless you use a very large resolution or multi monitors.

In fact, if you haven't already, here's a good guide on how to force Anti Aliasing and Anisotropic filtering, along with TrSS-AA (transparancy Anti Aliasing) using nVidia Inspector, as I know FSX has AA and AF issues. With your card, and because the game is CPU bound, enabling 8x MSAA (8xQ) and at least 4x SS TrAA along with 16x AF won't be an issue and will make things look so much nicer too.

http://forum.avsim.net/topic/291720-how-to-set-aa-in-fs9-and-fsx-for-nvidias-2xxxx-drivers-now-with-working-transparency-aa/

[Chike]

Re: Corsair RAM tighter timings?

Having said that, you may be able to tighten the timings, as like I say, it depends entirely on the modules you have as well as on pure luck that yours will run tighter.

I'll add the BIOS factor to those as there are some other settings to memory besides the main timings that unlike XMP we depend entirely and dare not touch(except very few who actually know what they do).
Yes I did mention that CAS does not come as time (but as fixed cycles value,) and still different frequencies in the profile have different CAS values.
Who knows maybe at the next "Enhanced memory compatibility" BIOS update you'll be able to lower the CAS to 6 up to, and beyond DDR-1370.

[earthdog]

Re: Corsair RAM tighter timings?

@psycho..I am running these settings already... and some other new tweaks too,thats why i was convinced to go to i7..First i sold my GTX295 which was a bad card for fsx and then my quad hold me back :))))) so after 1000+ euros here i am :)))


thanks...

next step is to try the dvid option with this setup

[Psycho101]

Re: Corsair RAM tighter timings?

I'll add the BIOS factor to those as there are some other settings to memory besides the main timings that unlike XMP we depend entirely and dare not touch(except very few who actually know what they do).
Yes I did mention that CAS does not come as time (but as fixed cycles value,) and still different frequencies in the profile have different CAS values.
Who knows maybe at the next "Enhanced memory compatibility" BIOS update you'll be able to lower the CAS to 6 up to, and beyond DDR-1370.

BIOS definitely is a factor, again which is why some "luck comes into it". Not pure chance OFC, I include in the "luck factor" anything a user can't really control. DFor most, BIOS programing is a complete mystery, myself included, so unfortunately we get what we're given on that.

I'm still hoping for a P55A-UD4 BIOS that will let me use my COrsair PSC RAM at all. All tests with regards to what my kit could do were on an ASUS board, sadly.

@psycho..I am running these settings already... and some other new tweaks too,thats why i was convinced to go to i7..First i sold my GTX295 which was a bad card for fsx and then my quad hold me back :))))) so after 1000+ euros here i am :)))


thanks...

I thought you might be. Most people into FSX are aware of the tweaks, but I am always surprised at the odd one or two (my uncle included, he's a Sesna pilot and loves FSX) who were running the game on a powerful rig with it looking awefull.

DVID is a good idea. If you pass Prime95 and LinX at those settings, then definitely give it a go.

On a side note, having the uncore as high as possible should bring some benefit in FSX, being so so CPU bound. The difference may be minute but it can be worth it for some. If you do lower Bclk, try and keep uncore as high as is possibe.

next step is to try the dvid option with this setup

[earthdog]

Re: Corsair RAM tighter timings?

yeap thats the road i am thinking..i tested dvid just..but i am getting stable when cpuz is using 1.296 as vcore......without dvid i am stable with 1.28 and lower temps.....

i think i ll go with fixed for now and try getting uncore higher...

but i see that if i raise uncore multi to 20 i have to put ram to 20 and thats getting my 1600 ram to 1740....do you think it will handle it if i get ram to 1740 and advance the timings to 8-9-8-24 from 7-8-7-20? and dram v as it is 1.66?

[Psycho101]

Re: Corsair RAM tighter timings?

You could try it. You should get at least DDR1700 at stock timings if you're lucky. Maybe 1740 will be possible too.

[earthdog]

Re: Corsair RAM tighter timings?

no i didnt get 1740 :))))

i went back to 23x174 and tighten timings to 6-7-6-18 and all is ok until now...will test her more with prime and some flying..:)))