prime95 fail

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Joined
15 Dec 2007
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78
Location
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finished a new build last week and it's been running ok, had a few problems getting hold of a driver but that's sorted now.
i keep getting a few odd restarts and errors messages poping up:(.

So i set about stressing it using prime95.
I've run all three tests and the results vary, using small FFT's it'll run fine, large FFT's it will fail after about 2 mins and on blend it fails after less than 1 min:mad:, giving rounding errors as a reason:

FATAL ERROR: rounding 0.5 expected less than 0.4

I get the feeling that it may be to do with ram as blend stresses ram and CPU while small FFT's barley stress the ram accoring to their descriptions.

SPEC:

Intel E4600
Gigabyte GA-73PVM-S2H
Corsair XMS2 2x1GB http://www.overclockers.co.uk/showp...me=Corsair 2GB DDR2 XMS2-6400C5 TwinX (2x1GB)
Antec NSK4480 incl 380w PSU
NO GFX card

any pointers would be appreciated, there doesnt appear to be any options for upping the ram voltages :mad: so i'm going to have a go at under-clocking it slightly to 750mhz
 
Small FFT's is CPU only. Large FFT's and Blend focus a lot on RAM so I'd definitely be looking into the RAM if the Small FFT's pass fine but the other fail quickly. Underclocking is not the best option - it's a bandaid on a problem that will probably arise again at a later point.
 
with it being a gigabyte board, try pressing CTRL + F1 on the main BIOS page to see if it unlocks more ram options to increase VDIMM
 
tried that

ctrl-f1 does bring up a few options, enables me to set the ram timings and choose the fsb etc but no options for ram voltages.:rolleyes:

Had a look at the rail voltages from the PSU and there not great so thats the first thing i'm going to try and sort out. it the nsk4480 psu and the +12 and -12v rails aren't even within 40% of acceptable there running at 8v and -16v!!!!the -5 is running at -8v so it's possible that doddgy power to the MB maybe the cause of the ram errors.

I managed to get it 'Prime stable' for now, got the ram at 750mzh with
5-5-5-!!!17!!!!-T2 :mad::eek: timings and prime seems to be running fine in the other room no errors *crosses fingers*, *touches wood*, *starts looking for lucky pants* lol.

Hopefully it's just a power supply issue

cheers for the replies guys
 
It does Sounds like your RAM isn't getting enough juice, According the the OCUK spec, The RAM can handle between 1.8 and 2.2v

What is yours at?
 
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not ure what i'm looking for TBH it's my 1st new build, bit of a noob; i assume it's vdimm as mame suggested? I can't see anything in speedfan and i don't remember seeing anything in BIOS about ram voltages wannabedamned
 
Even so, the RAM should automatically boot and support 1.8v @ 5-5-5-15/18 due to standardisation. All DDR2 ram has to be able to boot and fully support 1.8v at given timings.
 
managed to find ram voltage in BIOS, its running at 1.84v but there's no option to alter it. could it be that the board may need more volts to make it stable using two sticks?
 
it always booted fine, just wouldn't pass prime. default settings were 5-5-4-17-t2 but wasn't stable
Aye but if it's not passing Prime then it's not working properly :-)

managed to find ram voltage in BIOS, its running at 1.84v but there's no option to alter it. could it be that the board may need more volts to make it stable using two sticks?
It shouldn't, but try at 1.9v, then 2.0, then 2.1v maximum. If you go into the root of the BIOS where you have all the main sections, press CTRL+F1 and the screen should flicker which opens up the advanced settings. Then go into the voltage controls and scroll to the bottom and there should be an option called "DDR2 Overvoltage Control", set that to "+0.1v" then try (that's assuming Gigabyte BIOS's are generally the same layout).
 
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