Prime95 failing even on stock settings!

willg95

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first off, I felt this was the best suited category.

I have a recently upgraded machine from XP to vista premium and on XP I was running a DFI x38 board with 4gb (3gb in XP), 1gb each in each slot 1066/5-5-5-15 patriot RAM with an e8400 intel chip. I had it at about 4ghz (445FSB x 9) and the memory still at 1066. The overclock ran 48 hours in prime95 with the default blend test with 2 threads. stable in XP; but now in vista it fails within minutes overclocked, and fails in under 2 hours on stock settings! what could possibly be the problem???

and before anyone asks, on stock settings I did manually set the RAM to the correct voltage after defaulting to stock settings in the BIOS.

any help is greatly appreciated!
 

kyeana

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when you say 3gb's of ram in XP, are you implying that you added a fourth gig when you upgraded to vista? Or something along the lines of going from a 32 bit OS to a 64 bit OS?

I would download and run memtest 86+ and see how that fares. My initial guess is that it is the memory that is the problem
 

tmike

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have you checked the actual voltage when the box is up? my x38 (gigabyte) board's memory voltage sags once it boots, even if i have it set to the "correct" voltage, if i have all 4 slots occupied. i have to nudge the memory voltage up one extra notch with 4 sticks (along with my usual FSB and MCH increases).
 

ryanytchan

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i think memtest and super pi is a better program than prime 95 for testing your stability
 
^Wrong!

1. Memtest 86+ only tests RAM
2. SupperPI does NOT stress the CPU like Prime95 Small FFTs. P95, Ortho, OCCT are all about the same for stress testing. SupperPI is a benchmarking program and not meant as a true stress testing program.

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@OP:
Like said check RAM first. Also check temps. If your CPU is over heating even at stock (due to incorrect HSF mounting) then P95 will fail. Also are you running Vista x86 or x64?
 

ryanytchan

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no,you are wrong
for memtest i am talking about memtest 3.8,not the old version
if you activate 8 memtest in 64bit system then you can stress your system to 100%
i am using that now
for superpi i guess you don't know a low about it too
there's something called hyperpi which could stress all 8 cores and complete the test in a short time instead of running for the whold night like prime 95
it does not have to be a true stress program to know whether or not your system is stable.
 

willg95

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no. i had the 4 1gb sticks in with XP too. xp only read 3 out of 4gb since that's how it worked.
 

willg95

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and i have also tested memtest86 both in the operating system itself overnight as well as the deluxe version that runs off of a floppy on bootup and there were no errors in the tests. and i'm just running the 32-bit version of vista, fyi
 

kyeana

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so it doesn't sound like the memory is the problem (assuming memtest86 worked. It does great about catching bad DIMM's but is weaker in the bad timings department).

What i would do next is manually set all your voltages, CPU, North/Southbridge, ect, and manually set your cpu speed to stock settings (not using auto). Also for the time being set the Ram at a 1:1 ratio. This may underclock it a little bit, but will be helpful for determining what your problem is.

Another thing to check is if there are any new bios out for your board.
 

willg95

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it's a 700W thermaltake. and i'll try manually setting everything in the bios
 

willg95

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nope... set everything manually (what i could manually, most of the default settings were already correct). and now it just freezes up while running prime95. i even had he multiplier at 6x for 2ghz and it still froze. i even upped the voltage a bit while underclocked and it made no difference. :-\
 

kyeana

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Even if the auto settings has everything correct, go ahead and manually set them.

Any word on the bios update?

Also go ahead and try re downloading the newest version of prime95 and running it at stock settings with only 1 DIMM in.
 

willg95

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ok. i'l try the 1 DIMM and newer prime95 later. i have to go to work :(

i'll keep you posted

oh. and i do have the lastest bios update
 

ryanytchan

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how do you know? Memtest could run for days too
 

randomizer

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Memtest86(+) stresses jack all other than your RAM. It writes to RAM, reads it back and compares. Your CPU would have to be quite unstable to be unable to compare a bunch of patterns, in which case any real CPU stress tester would fail within seconds.

SuperPi is not HyperPi, you talk about one then the other. SuperPi is singlethreaded and inefficient; any barely stable CPU can pass it.

Prime95 Small FFTs provides a constant near-100% load which is why it is generally considered the best.
 

willg95

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well i took out all but one stick of ram and ran prime 95 on stock settings and now windows just freezes about 5 to 10 minutes in. sometimes it BSODs but it doesn't stay up long enough for me to read it. i'm starting to think this is hopeless. :(
 

randomizer

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You do know that (although quite rare) some people can run for days in Memtest yet can't boot Windows, right? Memtest is exactly what it sounds like: a Memory Test. It is not a CPU stress tester, and should not really be used as one.