Memory errors on XP 2500 unless core voltage lowered

Hi,

I have had problems with my computer ever since I bought it. My original parts were:
Athlon XP2500 barton, Abit NF-7s, Maxtor 80gig SATA, 512 meg no name memory, club 3D Radeon 9200, cd, low quality 350 watt psu

I got a lot strange shutdowns etc - knowing that low quality memory can give problems it lead me to do memtests (using memTest86). As guessed I got a lot of errors - trying to get around this problem I lowered cpu speed to 1100 where it ran stable for a few months.
Not happy with the situation I bought a stick of 256 meg Kingston memory, but it gave just as many memory errors. After that i bought an Antec True power PSU, but without improvement (after a suggestion in a forum - concering low quality in the PSU).
Then I found out by chance that if I lowerd CPU core voltage to 1,525 (instead of default 1,6) I could run my CPU at 1800 or even up to 2000 without any memory errors.

Happy enough I used the set for a few months - however, during a move the MoBo died (i guess through physical violence)...
Soon to send it off to repair/refund I have bought an Asus A7V8X-X MoBo... but my problem here is that the bios wont let me lower the CPU core voltage below 1.6 - forcing me to lower speed to 1467 to run stable without mem errors....

Does anyone have any ideas concering my problems?
Does anyone know if its possible to get another bios that allows me to lower the cpu core voltage (have upgraded to Asus latest)?

Thanks for any help!

Strange. Are you sure you're running the memory at the correct voltage?

did u replace the 512 altogether or just add that new stick to the memory you already have? just wanted to make sure

Tried it both ways... First I tried with the 256 Kingston alone - same prob - since then I've used them together as they both "bad".

I'm pretty sure that I have tried to change memory voltages as well... But most of the time I've had it on default - the lowest selectable (2.5 or 2.55 ... ? can't remember).

I've also tried moving the stick(s) in all possible mem socket combinations.

Thanks for your posts
/kalblo

Try upping the voltage (Vdimm) in your bios, so you can be sure of the effects. And what memory speed you are using?

I've tried different memory speeds - seems to work best with 400. Also - I spent some time today experimenting with mem voltage - raising seemed to help a little bit - I can now have lower delays on the memory (I raised them to max before).... It might also be the case that I got fewer errors at 1.833 - but I'm not sure. So still running at 1.4

"seems to work best with 400"? Is that what the memory is rated or not? "lower delays on the memory" is that referring to latencies? What are the specs of the ram?
Try clearing the CMOS to get everything back to normal, then look in the bios and be sure that the memory settings match the memory specs.

The memories are both 400 fsb. Thing is that I've tried most settings - I've also had the memories set at "By SPD" at most times - and yes "lower delays" was referring to latencies.
I have cleared CMOS many times before. And the frustrating thing is that the default settins are definitly less stable than my current settings as settings for AGP and the graphic card can also make it a lot less stable - stuff like "AGP Fast Write" is disabled etc.

Can you try this ram in another motherboard? This many problems with different parts might suggest that the ram itself is not the issue, maybe your board is not doing so well.

Well, I have tried it in two motherboards... Since the first one I had died (must have gotten bump as it was dead after I moved)... The problem is that the new motherboard doesn't allow me to lower CPU Core Voltage - the old MoBo (same parts) worked perfectly when I lowered it to 1.525 (instead of default 1.6)...


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I did however notice that the cpu temperature is "unnaturally" high (I think). The box had been on all day - running normal office stuff and the cpu temp is 60c/140f... Isn't that a bit to high? Could it be that the lower core voltage/clock keeps the temp down and it becomes unstable when overheating?
The cpu fan was rated to be able to handle Athlon XP 3400 - and it's happily running at about 2720... And I've got two fans for the box itself running as well...

That temp is perhaps on the high side of normal, but definitely not where I would expect problems. AMD's run hotter than Northwood P4's, so 60 isn't so high. Check that the heatsink makes good contact with the cpu. You could try taking a side off the case and blowing a fan on it, and see if it makes a difference.

I'm sure it makes good contact and opening the box doesn't make any diffence in cpu temp - I guess thats says that the box is ventilated enough. I havn't had any shutdowns due to high temp and it is stable at 60c... And if that isn't too high then the temp doesn't seem to be the problem...

Thanks for your posts

Glad to (try to) help. I'm of the opinion its the mobo, searching the web has shown other examples of this behavior that can be traced to the mobo. There are also examples of cheap memory not working well with athlons though, so it could be that as well. Can't tell unless you have another mobo handy to try.