Kuma 7750 wont pass prime95 UPDATE

1333 Views 19 Replies 6 Participants Last post by GMcDougal, Mar 23, 2009

GMcDougal

Discussion Starter · Mar 17, 2009

Ok, i just received my new 7750 and its doing the samething. runs in prime95 for about 25 minutes then one core fails out. Im not sure whats going on. Ive ran memtest86+ plus for 7 hours with no errors. Im running G SKILL 2x 2gb at 5-5-5-15 at 2.1 volts, 1066 mhz. im running the cpu at stock speeds and 1.325 volts.

Also, my temps are topping out at 55c with stock cooler. im running the large fft test.

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Dopamin3

· #2 · Mar 17, 2009

I'm thinking power supply. Check your PSU rails.

TheProfiteer

· #3 · Mar 17, 2009

yeah, if the RMA comes back with the same thing, I am thinking your 12v rails are drooping a little too low.

look at the way the voltage jumps while stressing. Try upping the vcore a little see if that helps.

TheProfiteer

· #4 · Mar 17, 2009

use a voltmeter to check your PSU, if that comes out ok, its your mobo.

GMcDougal

Discussion Starter · #5 · Mar 18, 2009

Ok, i just tried the small fft and it went an hour, no errors. i stopped it at one hour so who knows how long it would of gotten. any ideas as to why my system has no problems with this test but fails the others fast?

TheProfiteer

· #6 · Mar 18, 2009

small FFTs stress the CPU the most and produces the largest amount of heat. So a large vdroop (a falling and then rising of the vcore) might cause it to fail, thats why I suggested you should try upping the vcore a smidge.

Dopamin3

· #7 · Mar 18, 2009

2

Quote:

Originally Posted by Dopamin3

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I'm thinking power supply. Check your PSU rails.

Quote:

Originally Posted by TheProfiteer

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yeah, if the RMA comes back with the same thing, I am thinking your 12v rails are drooping a little too low.

look at the way the voltage jumps while stressing. Try upping the vcore a little see if that helps.

Read?

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vwgti

· #8 · Mar 18, 2009

Large ffts stresses more ram and chipset, so its either your ram or your motherboard.

GMcDougal

Discussion Starter · #9 · Mar 18, 2009

im thinking its my psu. the 12v rail just moves around too much, plus this psu has a bad past history. ill try to upgrade in the future and see what happens. thanks for all the help.

EDIT: well, this cpu must be better than the last one. ive been running prime95 for 2 hours, no errors...i just went to 3.0gigz and no errors as of yet. before as soon as i get 3.0gigz it would crash hard.

GMcDougal

Discussion Starter · #10 · Mar 20, 2009

I think i found the problem. I ran prime95 blend test for 4 hours, no errors. Bumping either the memory or the nb fixed my problem. my question is, if its the memory, do i rma it for .1 v off the advertised? same with the mobo?
i boosted memory from 2.1 to 2.2 and nb from 1.3 to 1.4. i just dropped the memory to 2.1 and see if it still passes.

elito

· #11 · Mar 20, 2009

should be your NB that needed the extra volt. cus that kit does 2-2.1 and it'll work.

GMcDougal

Discussion Starter · #12 · Mar 20, 2009

3 hours with mem at 2.1 and no failure. must of been the nb. should i rma the mobo over .1 volts? im thinking its the psu not being as stable as it should.

hellr4isEr

· #13 · Mar 22, 2009

hmm.. go to ur ACC seting and set that to AUTO.. i should help give ur cores the extra volts it needs to stay stable..

i belive its DISABLED by default..

GMcDougal

Discussion Starter · #14 · Mar 22, 2009

upon further testing, it appears its the ram, not the nb. i boosted the ram up to 2.2 and nb at 1.3 and it passed. when i tried the nb at 1.4 and ram at 2.1, it failed still. should i be concerned running my ram at 2.2? ill try the acc setting.

GMcDougal

Discussion Starter · #15 · Mar 23, 2009

thanks hell. the acc was disabled, im trying prime95 now to see if it fails blend test at stock voltage and speeds for everything.

hellr4isEr

· #16 · Mar 23, 2009

jus givin my 2cents

but for you memory.. if ur running it at stock.. go on newegg and see what voltage it should be at the advertised timings and set that.. my OCZ mem runs at 2.1.. and bios default is 1.9.. so make sure u set the advertised amount.. possibly check cpu-z "memory" tab to see what voltage to set for a specific timing..

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GMcDougal

Discussion Starter · #17 · Mar 23, 2009

im running it at 5-5-5-15 and 2.1 volts which is what its rated at. what should be my max temp for the cpu when trying to overclock on a stock hsf? also, what should be my max voltage?

hellr4isEr

· #18 · Mar 23, 2009

Quote:

Originally Posted by GMcDougal

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im running it at 5-5-5-15 and 2.1 volts which is what its rated at. what should be my max temp for the cpu when trying to overclock on a stock hsf? also, what should be my max voltage?

max temp for cpu.. i wouldnt go above 55C.. should jus get a new hsf.. fairly cheap.. around $20 for a decent one.. mine isnt even made for dual cores and it runs very nice.. max voltage.. on air.. dont go past 1.50.. otherwise get some very very nice hsf.. aka TRUE or Xigamtek..

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hellr4isEr

· #19 · Mar 23, 2009

go here: http://www.overclock.net/amd-cpus/45...0-oc-club.html

for your overclocking needs

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GMcDougal

Discussion Starter · #20 · Mar 23, 2009

ive got a problem....at 3.0 gigz its stable without going much over stock voltage...at 3.1...first few minutes during prime95 windows reboots. weird

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