what causes errors in prime small fft cpu test?

Tempered81

Diamond Member
Jan 29, 2007
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I'm running orthos @ 4400mhz 1.376v. It's giving me an error during small fft test, but the computer is not freezing up. Do i need more vcore, northbridge, vtt, vdimm, or sb?

 

yh125d

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Dec 23, 2006
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Gonna need more info.

what... FSB/NB voltage/Ram volts/Ram speed?
 

n7

Elite Member
Jan 4, 2004
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Small FFTs is nearly always CPU, assuming Memtest86+ passes.

So i'd look at vcore, or lowering CPU speed.
Blend does both small & large FFTs, but it first runs larger FFTs, which means if it fails right away it's generally either FSB, NB, or RAM issues.
Large is basically a good board test, as well as RAM somewhat.

At high FSBs, you might need to work with GTLs as well, depending on board, etc, but those should should up as errors within minutes of running either Large or Blend before they'll show up in small...
 

Tempered81

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Jan 29, 2007
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my error happens at about 50 seconds into small fft. I'll try more vcore - or try blend as you suggested N7, and see what happens. i ran 19 hours prime at 4000mhz...
 

n7

Elite Member
Jan 4, 2004
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LOL...4000 to 4400 isn't a small jump.

1.376v is really low...i'd be surprised if that's enough for 4.4 GHz.

Upping vcore is most likely all you need to do.
 

Tempered81

Diamond Member
Jan 29, 2007
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Well, blend is 5 minutes in and hasn't crashed. So if small is crashing, it must be v-core then? Thanks for your post, N7 - it was very helpful.
 

n7

Elite Member
Jan 4, 2004
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Well, blend not crashing likely means the FSB/NB/RAM is stable, or at least close to.
Blend doesn't really stress the CPU much till it switches to the smaller FFTs, so if you keep running Blend, watch it fail when it switches from 1024k to 8k...it'll likely fail once it hits 8k.
 

Tempered81

Diamond Member
Jan 29, 2007
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almost 10 mins in and blend still doing fine. small fft was crashing around the 50 second mark every time. This has to be v-core. And this board friggin sucks for vdroop / vdrop. 1.48v in bios, 1.42v idle, 1.376-1.39v PRIME, 1.360v Linpack.

WTF?

edit: what program is it that monitors vcore and reports in in a graph/log (so you can see spikes)?

 

Tempered81

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Jan 29, 2007
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How far into it does it hit 8k?

@ yh125d : vdimm is at 1.95v @ 441mhz 2x2gb g.skill. nb @ ~ 1.5v, vtt & sb @ auto

 

n7

Elite Member
Jan 4, 2004
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On my quads, it hits 8k at about 18 minutes in.

Can't remember if it's the same for duals.

But if you cannot wait 20 minutes, just go reboot & bump up vcore; then do some more small :p
 

dbcooper1

Senior member
May 22, 2008
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Originally posted by: jaredpace
almost 10 mins in and blend still doing fine. small fft was crashing around the 50 second mark every time. This has to be v-core. And this board friggin sucks for vdroop / vdrop. 1.48v in bios, 1.42v idle, 1.376-1.39v PRIME, 1.360v Linpack.

WTF?

edit: what program is it that monitors vcore and reports in in a graph/log (so you can see spikes)?

OCCT