Cas timings

[Hew Jazz]

Ok, I got two sticks of Infinion ddr400 cas 3 ram. I am running my Barton2500+ on a 400fsb(=3200+). I'd like to try to bring my ram down to 2.5 timing but I have no idea what the settings would be for that. 2-2-2-5? Appreciate any info.

 

[Thorny]

If you take your settings that low, prepare to clear your cmos. Check what your timings are now in bios and and lower them one at a timel. The ones you want to look for are (in order x-x-x-x) Cas-TrcD-Trp-Tras. With value ram running at rated speeds you probably won't get to much lower timings. Be sure to use memtest and only change one at a time. Good luck.

 

[sbuckler]

Note: if you performance test using something like 3dmark01 you'll find cas timings have very little effect (contrary to popular belief) - order of importance for lowering timings I think are c-a-b-d (i.e. 'a' is the most important timing). Forget cas for now and slowly try lowering the middle two numbers.
Oh value ram does run at tighter timings sometimes, my old crucial value DDR400 with timings of 3-4-4-8 would run happily at 2.5-2-2-6 believe it or not!

 

[Hew Jazz]

Ah man, this all sounds so complicated. So I want to bring the #'s down? Doesn't cas 2.5 ram at 400MHz have all the same timing? Im not sure what mines at. I have the bios set as Auto.

 

[sbuckler]

Its not really - you just need to turn it off auto which should hopefully default to the correct timings (if it doesn't you could try and find the manufacturers timings or just start on something safe like 3-4-4-8, or maybe 3-3-3-8) and slowly tighten the timings - i.e. lower one of the numbers, test to see if it crashes (lots of free mem test apps around), lower another, etc.

 

[Navid]

Use CPU-Z to see what your current timings are.

 

[suszterpatt]

Go to Corsair's homepage. The RAM guy there has very good explanations about timings and how RAM works in general.

 

[Hew Jazz]

Originally posted by: Navid
Use CPU-Z to see what your current timings are.

Sweet program. It states that my slot one ram is running at 2.5-3-3-8 and my slot 2 is 2.5-4-4-8. There both 512megs, CAS 3 and DDR400 sticks. Both made by Infinion.(Identical Ram) Is it ok for them to be different like that or can that cause hiccups? The motherboard has it setup like this automatically. I haven't tried making my own adjustments yet. Curious about the difference between the two. ?

 

[coomar]

shouldn't the ram be running the same timings?

 

[Navid]

Originally posted by: coomar
shouldn't the ram be running the same timings?

As far as I know, it should. I don't understand either. Waiting for someone to offer an explanation!

 

[coomar]

i would have thought he's telling us the spd reading that cpu-z gets from the chip, whats its default settings are, in cpu-z, the spd tab gives you the memory's rated speeds, the memory tab tells you what it is actually running at

 

[Amaroque]

AFAIK It's impossible for two sticks of RAM running in dual channel to be using different timings!

 

[Gophermofur]

Try looking at the memory tab instead of the SPD tab. I'm not sure why the numbers are different for your sticks in the spd tab. Anyways, in the memory tab there will only be one set of numbers, or should only be one set of numbers, and make sure you are running dual channel, which will be indicated by the word 'dual' in the top right corner of the memory tab.

Mo

 

[monster64]

I think he mightve been looking at the spd the first time. Make sure you are looking under the memory tab. You can't get two different readings if you are looking at the memory, because there is only one set of timings to look at and no way to select another slot, but you can do those things in the spd tab however. Check again and make sure you are looking at the memory tab.

 

[Hew Jazz]

Nope, its in the memory tab. I tried setting up the ram in the bios as 2.5-4-4-8 but cpuz still shows the first stick running as 2.5-3-3-8. By the way, its "not" a duel channel motherboard.