Memory timings / errors help.

[pepsimax2k]

Hey all, I just got a GA-MA69G-S3H with a 4200+ and 2 x corsair xms2 667 4-4-4-12 (2.0v).

Having stuck it in, presumably because of the mobo's default support only for 1.8v ram, it loosens all the settings to 5-5-5-18, so my first question would be which of these lot should i change to get 4-4-4-12. there's quite a few other options there... I think it's cas latency, ras to cas r/w delay, row perchance time and min ras active time. but, see my second question...

http://www.pcstats.com/article.../GBTma69GS3H_bios1.jpg

second thing is, memtest86. when running it either at default settings or tweaked to the above to try and get 4-4-4-12, it says either 5-5-5-18 or 4-5-5-18 (tweaked). is there a problem with it reporting timings correctly? also, it gives the speed as 367MHz (DDR735) which suggests it's set to DDR800 in bios, but it's at 667. when changing to DDR533 in bios it reports this correctly. afaik cpu is set correctly but i'm not too sure what's used to calculate ram speed in the bios these days.

and then the biggest problem is, on test 2 at 20% it just starts increasing the error count and dont stop, and the program seems to freeze with a reboot needed to exit. so either one of the ram settings are wrong, previous wrong settings messed up the ram, ram's in the wrong slots or one/both of the ram are bad, though i have no way of testing the latter...


this is the error i'm getting on memtest, with 1 stick set to 533 / 5-5-5-18. and i'm also using 256mb assigned to onboard video; nothing to do with that is it?

http://inaudible.co.uk/temp/memerorrs.JPG

 

[BonzaiDuck]

Don't know how useful my remarks would be here.

I'm not all that fond of your Mobo's BIOS-screen layout.

I'm guessing that once you set "DDRII Timing Items" to "Manual," everything shows to be what it would be under "Automatic."

I can't understand why there are settings for four modules when you have only socketed two. (Trfc0 through Trfc3).

The six items that have the biggest value for tweaking are: tCL or CAS# latency, tRCD or RAS to CAS [R/W] Delay, tRP or Row Precharge Time, tRAS or min RAS ACtive Time -- for the four basic timings in that order. After that, notice that Row Cycle Time (which I BELIEVE is tRC also known as "bank-cycle-time") is already set to 21T, which (on the BIOS-screen-photo) nicely coincides with tRP + tRAS = 5+16= 21. Finally, the screen shows a default 2T for the command-rate. Under some circumstances, with the "right" memory and the "right" FSB speed and voltage, you can run command-rate = 1T, getting a hefty boost in bandwidth.

I don't trust MEMTEST86 lately -- and for a single pair of memory modules, I am much more comfortable with MEMTEST86+ v1.70 or later. You can also look at MicroSoft for the MS Memory Diag, installable on floppy and runs like the MEMTEST86 programs.

Your BIOS seems to have a setting for "Memory Clock" like some older boards I've seen allow you to set "DDR 333," "DDR 400," "DDR 500" etc. With that approach, and for DDR(1) memories, we would set "DDR 400" for a pair of DDR 500 modules, and then raise the board's FSB setting to achieve an effective DDR 500 memory clock.

So if your CPU defaults to 1,066 FSB, set the memory clock to DDR 533 and the lowest of SPD/EPP tCL,tRCD,tRP,tRAS timings. If the CPU defaults to 1,333 FSB, set the memory clock to DDR 666 or 667.

Test the memory at default CPU, FSB and timings with MEMTEST86+ (or other) before you start over-clocking the board and components. You'll re-test each time you increase speed or tighten latencies.

DDR2 is apparently a slightly different "ball-game" on "timing formulas," and it's been shown than tRAS can be set lower than the conventional rules dictate. The conventional rules, however, follow along these lines:

tRAS >= tCL + tRCD
tRC >= tRP + tRAS

With DDR2, tRCD gives even more significant gains than tCL for tightened latency, but stability is sensitive to both. You should be able to tighten tRAS to at least +1 over what the formula suggests, once stability is attained for tightening the first two, and without ruining stability. And you should be able to tighten tRC by formula or no higher than +1 over what formula dictates, with no impact on stability at all.

The other settings can be left alone, and may have larger impact on stability and virtually no impact or little impact on bandwidth.

 

[pepsimax2k]

thanks. that first pic isn't actually mine so the settings are different, though it is the same board. it's an amd processor and i think the fsb is 200, though i have all cpu settings on auto.

the reason i have mem settings on manual is that it doesn't use the correct settings automatically (defauts to 1.8v and lowers settings; i have a 2.0v pair with tighter settings).

and i've just swapped sticks about trying out different locations and that doesnt stop the weird errors, so i know the board's ok, and either both or neither of the sticks are ok, and the settings are presumably ok (though i can't figure out how to get 667; 533 gives 533 and 667 gives 800 settings :| )... mebbe should just try old memtest methinks...

edit: ahh good ole memtest. 1.70 is currently on test 4 50% through with no errors. a lot further than 3.x got but another stick and a few more hours to go yet... now i only gotta figure out this 667 thing. only took 24 hours to get this far...


edit 2:
my settings: http://inaudible.co.uk/temp/mem2.JPG
memtest reported settings @ 667: http://inaudible.co.uk/temp/mem1.JPG
memtest reported settings @ 533: http://inaudible.co.uk/temp/mem3.JPG

the 4-5-5-18 and 667 reported as 735 are my main concerns now...