Prime95 errors sure sound like RAM /CPU. This page, "Torture Test Your CPU With Prime 95" says that if you cannot decide whether the CPU or the RAM are causing the errors...
http://www.playtool.com/pages/prime95/prime95.html
Well worth reading through.
It's just not that easy to completely isolate the problem which causes Prime95 to fail. It's usually the CPU but sometimes it's something else. The only way to be 100% sure is to swap in replacement components until the problem is fixed. You just have to do as many tests as you can to make your best guess about which component is responsible before deciding which one to replace or adjust.
To help you make that guess...
When Prime95 fails in any way, the very first thing you should do is run a memory test to rule that possibility out. MemTest86 is a very thorough memory testing program. If your memory passes the tests then you're pretty much down to the CPU and the CPU/RAM interface as the most likely causes although there are some other possibilities.
And,
If you have the kind of CPU which accesses its RAM by communicating with a northbridge chip on the motherboard, then your CPU is probably the problem but the northbridge could also be responsible. The RAM data is passed in both directions between the CPU and northbridge and if the northbridge is a little weak, it may have problems communicating with a hot CPU. If you're not sure what to blame then you can try running only the "small FFTs" test. It does very few RAM accesses while running the test. If it fails, then it's very likely to be the CPU which is at fault. Unfortunately, that's not 100% guaranteed because even the small FFTs test still accesses RAM and does other things like read and write disk files.
It also mentions as another possibilty, overheating CPU. You are happy with heatsink size, placement, thermal contact, etc? Are you monitoring temps?
Prime95 fails on both large and small FFT tests, superpi cannot complete calculations over approx 128K, failing sometimes instantly and sometimes longer.
Memtest has been run on RAM and passed at least 2 runs, I also noted, looking at the RAM i purchased:
http://www.pp.co.nz/products.php?pp_id=MEM00092 that I was sent different RAM or a different revision of the RAM, because I distinctly remember not paying over $100, though the RAM looks more like this:
http://www.pp.co.nz/products.php?pp_id=AG00234, because it has smaller mem chips.
If someone wouldn't mind double checking my findings regarding Motherboard/CPU/RAM compatiblity here are their names:
Ram screenshot in CPU-Z
CPU Temperatures are always around 45-50celcius and in the short time PRIME95 runs it never gets above 55. I looked around in BIOS and cannot find any settings for Vcore and frequency is already at lowest. I tried turning off EIST and C1E, though no difference... Remeber I have NOT overclocked this machine AND the older
celeron D 336 works just fine when downloading/installing files and archives, and performing stability tests though
Pentium D 915 stuffs it up. Vcore on CPUZ jumps around from 1.248-1.256.
I have performed Prime95 and SuperPI tests with this new PSU, which has all 20+4 pin connectors.
I would try the CPU on my new machine, (in siggy) though the specifications are too different and I'm just not risking anything lol. Bad idea.
Heres a summary of what I've changed and what the problems are:
- Problems
- Downloading and/or installation/extraction errors with archives and moderately large .exe installers (~>5-10mB?, I know the nVidia driver never works, 35mB).
- Fails stability tests and reportedly has crashes/reboots without warning when playing moderate CPU intense games (Halo).
- Remember none, to my knowledge, of these errors have ever been replicated when running a Celeron D
- Changed
- Swapped RAM DIMM after recommendation from CPU seller after CPU was returned and returned... with no errors reported.
- Swapped PSU to 430W with 20+4
- Changed HDDs and IDE cables
- Ran Memtest68+ and Seatools/CHKDSK
- Changed BIOS settings, disabled C1E EIST, reverted to Fail-safe defaults AND downflashed bios to previous revison.
Finally, here are some queries, why does CPUZ report 266mhz ram when the sticker clearly states 533 and the motherboard supports that. Why are these errors not replicated with Celeron D processor?
Should I send the CPU back to Intel instead of retailer and run the Celeron D for the meanwhile, if recommended?
Thanks, I hope I haven't supplied too much information and that it is easy to understand.
@someone that will help esp. contrex, any chance you can add me on MSN?:
[email protected]
