PDA

View Full Version : CPU voltage affecting memory stability.

mysterfix
07-02-07, 11:36 PM
If anybody else has heard of this before please share your experience.

OK, I've been recently testing some new ram lately (Crucial Ballistix PC2-8000). Originally I could not get this kit to run stable even at default settings running DDR928 which is 1:1 with my CPU @ 3.7ghz 1.5v.

Now keep in mind that this CPU has been tested Orthos stable for a little over 18hrs. which was stopped by me due to impatience.

SO changing memory voltage and using various timings had no affect on stability at all, the longest I could get this kit to run stable was about 2 minutes with orthos. It tested fine using memtest86+ v1.7, superPi 32m, and various 3d benches but would not run orthos for more than a few minutes. It also would not run Stalker for more than 5 minutes without crashing.

After playing around with MCH and FSB voltage I decide to up the vcore a little. Imagine my surprise when orthos actually ran for 45 minutes before it crashed! So I have reset MCH and FSB voltage back to default and vdimm to 2.2v and am so far an hour and 15 minutes into the testing with vcore set to 1.53v and rams running @ 1160mhz 5 5 5 15.

I'll update this in the morning whether it crashed or not during the night.
Roisen
07-03-07, 03:34 AM
I have never heard of this happening, nor can I figure out how it could...
mysterfix
07-03-07, 06:51 AM
Update: The test ran till 5am, till my kitten decided he needed to play with all the nice wires behind my desk. Needless to say I plugged the computer back in and will be restarting the test.
mysterfix
07-03-07, 06:18 PM
Well this kit ran stable for 8+ hours while I was at work after a simple vcore boost up to 1.53v all other voltage set to normal except vdimm which is set to 2.2v, gonna go for 24hr. orthos next.
EmAn
07-03-07, 06:24 PM
hmm... this is definately weird but may it be a signal for failing hardware?
MadMan007
07-03-07, 10:31 PM
Maybe the CPU cache or the part of the CPU which interfaces with the FSB and thus the memory needed a touch more voltage to run those speeds. Even though Intels don't have on-die memory controllers which directly affect the memory oc'ing like A64s it's still within the realm of reason that CPU voltage could affect Ram stability, the CPU still interfaces with the Ram after all. I suppose one could argue that's really the CPU stability but when looked at as a system :shrug: stable is stable ;)
mysterfix
07-05-07, 10:00 PM
Alright guys I finally got around to cmpleting my 24hr. stability run. passed with flying colors but when I booted into Vista the fsb speed shows it being off by 2 but I assure you it is set to 464mhz in bios.

http://img366.imageshack.us/img366/5013/stability1gy9.jpg (http://imageshack.us)
Enablingwolf
07-05-07, 10:09 PM
The only way I would think that it would effect the RAM would be Gigabyte decided to automagically link the voltages in sync for easier managment of them. Sometimes Gigabyte does strange things like that. Their BIOS and boards are stable, but quirky.

Do the Intel variants do the Ctrl+F1 like the AMD counterparts? Why they do that and slightly overvolt. I have no clue. It has been ages since I seen the innards of a Gigabyte Intel BIOS.
mysterfix
07-05-07, 10:30 PM
The only way I would think that it would effect the RAM would be Gigabyte decided to automagically link the voltages in sync for easier managment of them. Sometimes Gigabyte does strange things like that. Their BIOS and boards are stable, but quirky.

Do the Intel variants do the Ctrl+F1 like the AMD counterparts? Why they do that and slightly overvolt. I have no clue. It has been ages since I seen the innards of a Gigabyte Intel BIOS.Yes, exact same process for unlocking extra features in bios. The CPU voltage is spot on with vdroop being almost nonexsistant. I haven't quite figured out which mosfet to measure the vdimm from. One shows an overvoltage of .5 on the vdimm while another right next to it shows only .05 overvoltage. Maybe each one is for a different memory channel?:confused:
Enablingwolf
07-05-07, 10:38 PM
Yeah, Gigabytes are strange critters. The one thing I did find out about the maker. If you call the LA(USA) number. They try to answer any questions you may pose. They are pretty darn good about that usually.

If you don't mind making a long distance call. You could probally call them and find out what you seek.
mysterfix
07-05-07, 10:41 PM
Well, that's good to know, maybe I'll give them a call tomorrow after work and if they can't shed some light on this.