Prime95 stable for 12 hours - crashes in games

M

meatfestival

[H]ard|Gawd
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Apr 5, 2005
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Overclocked my San Diego 3700+ to 2.8ghz. I primed it for 12 hours with no problems, it's also been folding away as usual and Windows in general is fine.

But any games will make it crash or blue screen after a short while. If a game crashes to desktop then the rest of the system starts getting unstable, eg programs running in the background seemingly doing nothing will also start crashing.

Increasing vcore didn't help so I backed down to 2.7ghz and it seems OK in games so far.

Anyone else had this behaviour? I'm using a Lanparty SLI-DR with 2x 7800GTX. My ram is on the 166 divider. I've bumped up memory voltage to 2.9v and chipset to 1.6v. Memtest is also OK at 2.8ghz.
 
Sounds like the CPU is stable...

so maybe PSU issue, GPU issue, Memory issue...

Thats where to start.
 
It's an enermax noisetaker 600w (SLI cert). Dunno about power, I mean it should be drawing the same amount at 2.7ghz vs 2.8 since I'm not changing the vcore or anything.

I can certainly get by alright with 2.7ghz, I mean it's a huge difference from 2.2ghz anyway. Would just be nice to match an FX-57. :)
 
You should be fine with that PSU (more than enough power) - what kind of temps are the GPU and CPU hitting in games?
 
Under load, CPU about 55c (1.6vcore), GPUs 80c. Fairly hot I know, but should be well within limits.
 
Actually i dont think the 7800GTX's work well that high, mine never went above like 60C, now my X1900XTX is another story.
 
0V3RC10CK3D said:
Actually i dont think the 7800GTX's work well that high, mine never went above like 60C, now my X1900XTX is another story.
Click to expand...

actually my GTX loads arounds the same and its been fine for year+
 
I doubt it's your psu. My system is using SLI 7900gt's vmodded 1.5 and oc'd to hell: 640/840. Cpu will burn at 2930-2950. But when it comes to games I've got to knock it down to 2880 to run completely stable on all games. Some games I can get away with 2900-2920 mhz but most I can not. My psu is only a 500 watt enermax Liberty with dual 22a rails. My system pull a consistent 340-425 watts and peaks about 470 watts for a breif second or two. See my post
http://www.hardforum.com/showpost.php?p=1029600317&postcount=20

Sometimes a chip just cant run 3d as high as non-3d. Regarding pulling more watts, overclocking itself pulls a little more out of the system, but it's the vcore increase that I've noticed that yanks the watts out of the wall. You can really decrease your energy use when you knock the vcore down to like 1.0v when downloading, I get about 120 watts pull even with both video cards, 2 drives, dvd-rw, swiftech water pump, 2x120mm fans, & fan controller in at that low vcore,
 
Seems more like a memory timing issue, depending on your memory divider and how strong your CPU mem controller is it can cause issues. Please list your memory and timings. Usually instability in games at least for me means I need to tweak my drive strength and data drive strength's. Also just because memtest passed doesn't guarantee stability in windows especially in games. Good resources for DFI mem timings are http://dfi-street.com/, http://www.xtremesystems.org/forums/. :)
 
Here are some options that might help you out.

1) Run 2 x Prime95 select test as blend

2) Run Memtest from bios, and only select test #5 and require to pass up to 40 times.
 
My system is like the exact opposite. The blend test in Prime failed after like 20min, but I can run any game out there and I've never had a crash.

I don't wanna hijack this thread but is not having a prime stable system 'bad' for it?
 
Ah OK, couple of things there that I never thought to try - thanks. Will let you know what happens.

I have 2x 1GB OCZ Platinum EL PC3200. With the current settings it's running at 210mhz 2-3-2-5. At 2.8ghz it was roughly 213-214. I've tested it successfully at up to 215mhz at those timings. I did try some tweaks for that particular ram off the DFI-Street boards, but then I couldn't even get it to boot up. However it was a while ago, so I will have another look and try again.
 
Definitely sounds like a HTT/HT issue, but I've had sagging VCore cause CTD in 3D. Like bail_w recommended, test #5 can get the memory warmer than any other stress IME and is very sensitive to overclocked speeds. That'll stress the memory particularly well. Usually 40-50 passes is a good benchmark to call it stable, even if it errors out at say 75 or 100 passes.

Have you also tried bumping the NB/LDT voltages? Perhaps different RAM slots?
 
This happened on my sons PC i overclocked and it was the GPU.

I used www.passmark.com and they have a burn test and a performance test and on the preformance test it always crashed on the 3d plane bit and i thought i took the overclock a bit too high.

But after checking all the components it turned out to be the GPU.

His system still runs a 4.15ghz to day (pentium d 930)
 
Optic said:
My system is like the exact opposite. The blend test in Prime failed after like 20min, but I can run any game out there and I've never had a crash.

I don't wanna hijack this thread but is not having a prime stable system 'bad' for it?
Click to expand...

This could be due to insufficient voltage. I have a 2800+ Barton running @2.5GHz that is not prime stable, but it is stable in games and other apps. At 1.8v, Prime freezes the system. At 1.85v, I am stable, and Prime simply returns wrong answers (but doesn't hang).

OP: 12 hours of Prime (or so I have heard) will not catch every conceivable possible instability. 48hours of prime, plus some Sandra would be more thorough.
 
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