How many hours of Prime 95 is considered "acceptable"?

[imported_Sincity]

Just completed my first overclocked A64 system. I have been running Prime 95 for 16 hours and 36 minutes before it failed. What would most people consider "acceptable" for a stable running system?

My specs:

HTT 4x
CPU 260 x 10 @ 1.475V (E6 3200+ week 50)
Memory Divider 333 @ 216mhz
Timing: 2.5-3-3-6 1T @ 1.7V (Corsair 3200C2PT)

Should I pump the Vcore to 1.5V?

 

[thecoolnessrune]

To be stable i would have to say it shouldn't fail after 24. Actually, it really just shouldn't fail.

 

[imported_Sincity]

I ran the blended test. But it looks like Prime 95 even overclocked the amount of time it was testing. I started 1 pm this afternoon and it is now almost 9pm. It really only ran for 8 hours or so. That is strange.

I am now running the Large FFTs test and bumped voltage to 1.5V.

Shouldn't fail even after 24 hours? Maybe my OC goal should be 2.4-2.5 ghz.

 

[BOLt]

I get 2.52GHz (280Mhz x 9) @ 1.6V on my A64 3000+ (Venice) E6 stepping. You should be able to get 2.6GHz with 1.5V, which is a very reasonably voltage. Try for 267MHz+ on the FSB so that you can get 200MHz out of your RAM. I'd say put 2.8-2.9V (which is a safe for all RAM) in the RAM, 1.525-1.55V in the VCore, and set the memory to 2-2-2-7 CAS latency at 1T at PC2700 speed. Then crank up the FSB until you don't post. Drop it 10MHz and run Prime95. Done. I'm thinking 2.7GHz easy, 2.8GHz possible. The E6 chips are tough because they don't go as high as they should (as compared with E3s or even E4s). In any case, good luck, and I hope you'll realize that even 1.55V on the VCore is still acceptable and will not compromise the life of your CPU to a great extent (hey, practically any overclocking will shorten the life of the CPU, but they are designed for over a decade of use -- are you planning to hang onto your processor for that long?).

Good luck and let us know what your results are like!

EDIT: Don't forget to bump up your chipset voltage by .1-.2V!

 

[mrkun]

Eight hours is generally considered to be stable. There's no reason to raise your voltage.

 

[BOLt]

Originally posted by: mrkun
Eight hours is generally considered to be stable. There's no reason to raise your voltage.

The E6s need more volts in the VCore to get more than a 500MHz increase in my experience and from what I've heard as the general concensus (sp.?).

 

[nealh]

Originally posted by: Sincity
I ran the blended test. But it looks like Prime 95 even overclocked the amount of time it was testing. I started 1 pm this afternoon and it is now almost 9pm. It really only ran for 8 hours or so. That is strange.

I am now running the Large FFTs test and bumped voltage to 1.5V.

Shouldn't fail even after 24 hours? Maybe my OC goal should be 2.4-2.5 ghz.

I will bet the ram is the issue...lower the settings....blend test..tests ram more than cpu

try 2.5-3-3-7-1t..I bet she does fine

also...there are many who feel 24hrs of Prime 95 is a must, some say 48hrs
Personally I like to 12hrs, small, large fft and memtest(6 hrs)...A custom torture test from DFI is a very good compromise

http://www.dfi-street.com/forum/showpost.php?p=158518&postcount=1

My last 2 A64 setups that were 15 hrs Prime 95 stable never had any issues for gaming, video encoding etc

Prime 95 in readme says 6-24hrs....so whatever you feel best suits you....

8hrs is good spot as well....when will you ever place your setup under full load for 8hrs

remember instabilty can be drivers, apps not playing well together too..winxp is a monster so many places for issues

Someone posted why would you run small fft this is no test of stabilty...well I want to know where my cpu fails...if it does 12hrs plus then I know cpu is ok, I test ram separately to make sure I know it will be ok(now memtest stabilityy does not always equal winxp/game stable sometimes you need to lower speed a bit or timings a touch)

then I run large fft (but a blend test or custom torture test maybe better) to check for xp stability at a given overclock.....

The Problem with stabiltiy, is any time you change something ..stability may change

I have Opteron 165 I was testing. I ran it with ATI Omega Cat 5.12 for 12 hrs Dual prime95 stable..decide to update to 5.13 for better dual core support and CCC..well tried to run prime95 and it would die
it seems it had to do with my monitor power save feature..I set my monitor to turn off after 20min and these drivers...rollback no issue

then i installed 5.13 with old CP and no .net and CCC and ran dual prime for 12 hrs again

It was not my cpu or ram but video driver/system issue...damn it was frustrating

 

[nerp]

In theory "stable" would mean Prime could run forever without failure. This is always my goal. ANY failure in Prime, no matter how long it takes, is a sign of instablity to me. I want to be able to leave my machine running 24/7 with no concerns.

Many people view things differently and are satisifed with more than 8 hours prime stable before a failure, and will accept that failure. Sure enough, in most cases, you won't get errors in Windows and games won't crash.

But imagine the following scenario: Prime fails after about 10 hours.... You're fine with that. . . Two weeks later a program crashes and you lose the taskbar, having to CTRL-ALT-DEL to bring up task manager and reboot.

Was it buggy software? Or your overclock?

That kind of question can drive you nuts. By making sure that the machine is 100% Prime stable, you won't agonize whether the weird quirk in a program or the one-time flicker of green ****** in a game is your hardware crapping out or a software bug.

Besides, doing a long encode might cause a crash or failure if Prime fails.

 

[Mrvile]

For testing the CPU itself you should run the Small FTTs test. It stresses the CPU harder and doesn't use any ram. For ram testing you should use Memtest instead of the Blended Test in P95 - Memtest is more complete and doesn't use the CPU.

 

[nealh]

Originally posted by: Mrvile
For testing the CPU itself you should run the Small FTTs test. It stresses the CPU harder and doesn't use any ram. For ram testing you should use Memtest instead of the Blended Test in P95 - Memtest is more complete and doesn't use the CPU.

Agreed but in windows environment Memtest stability does not equal video/prime stresss stable always

often memtest will give stable ram settings with slighter mhz than may run in winxp or video games....


Nerp ...
the problem with you theory is you can have a stable cpu,ram and Prime95 runs forever but video games will crash, or another app..I see it posted on the forums all the time

Prime95 does provide a secure sense things should be ok but once apps, drivers go on our OSes stablity can and often does change...not alwyas hardware

In my recent experience if I pass memtest, small and large fft..I have had no hardware failures...I like to run 15hrs with Prime95 and 6hrs of memtest

This may not be acceptable to you but I do not run Prime95 in background forever...no reason too and this would be the only way t oprove 100% stablity all the time(I guess)

I had an opteron 165@2610 that never failed prime 95 once I installed the ATI cat 5.13/CCC/.NET....it would not run dual Prime....unloaded this software no issues with dual prime

I can install cat 5.13/old CP no .NET and turn off my monitor power save to never and Prime95 runs ..for some reason this power management caused issues

 

[nerp]

Yeah, you bring up good points. I guess to clarify, I wouldn't accept any problems in regular software either. If prime was stable but I had persistent issues, I'd keep reducing my overclock until they AND prime both operate without a hitch.

The true test of any overclock is whether the machine will hold up to YOU.

 

[nealh]

Originally posted by: nerp
Yeah, you bring up good points. I guess to clarify, I wouldn't accept any problems in regular software either. If prime was stable but I had persistent issues, I'd keep reducing my overclock until they AND prime both operate without a hitch.

The true test of any overclock is whether the machine will hold up to YOU.

I agree 100%...I test stablity early on but do not go back every month after screwing around and recheck..which is probably necessary but the only crashes I have had recently have been due to software changes..I always keep a good Acronic TrueImage backup around

 

[blackangst1]

Originally posted by: Sincity
But it looks like Prime 95 even overclocked the amount of time it was testing.

ROFL this caught me as funny

 

[thesurge]

6hours.

 

[qoou]

ten minutes. really what difference does it make if it crashes after 16 hours? playing games and if it only crashes once per day thats no big deal. Its not going to keep you from running that oc effectively.

 

[richardrds]

Originally posted by: qoou
ten minutes. really what difference does it make if it crashes after 16 hours? playing games and if it only crashes once per day thats no big deal. Its not going to keep you from running that oc effectively.

Hope your current job has nothing to do with Quality Assurance!!! I had my winnie set at 2.5Ghz and it failed Prime stress test after 13 hours, i was going to just say F@#4 it and consider my PC stable, but i just couldn't sleep at night wondering if i was really 100% stable, so i backed my OC down to 2.4G and ran prime stress again and reached 24 Hours, i immediately stopped the test ( with my luck it would have failed at 24hours and 1 minute, LOL).

 

[DrMrLordX]

Originally posted by: qoou
ten minutes. really what difference does it make if it crashes after 16 hours? playing games and if it only crashes once per day thats no big deal. Its not going to keep you from running that oc effectively.

Same crap as you posted in the Presler thread. Meh.

To the OP, go for 24 hours with no crashes. If you can't get that, something's wrong somewhere. Also, I would highly recommend running Prime at stock settings in small FFTs before you try overclocking at all to see if your rig has any defects.

 

[CP5670]

I use 12 hours with small FFTs. It's good enough for me, anyway.

 

[themusgrat]

If you don't want stability, 10 min is ok. I test 24 hrs small FFT, 4 hrs large FFTs, and 4 hrs memtest. That is considered stable to almost anyone. BTW, I have had a core fail after 10 hrs and like 45 min, so be careful.

 

[designit]

Originally posted by: Sincity
I ran the blended test. But it looks like Prime 95 even overclocked the amount of time it was testing. I started 1 pm this afternoon and it is now almost 9pm. It really only ran for 8 hours or so. That is strange.

I am now running the Large FFTs test and bumped voltage to 1.5V.

Shouldn't fail even after 24 hours? Maybe my OC goal should be 2.4-2.5 ghz.

Most of the time prime fails if cpu gets too hot. It could be you ran it during colder hrs and your room temp raised during the day thus making the case ventilating warmer air.
It could also be your home electricity peak and your power supply fluctuated to a lower end. I suggest using the power surchrge and only plug the cpu to it. Also use minimal electricity in the house (the HVAC units use a lot of amperage).
Do above and let see if helps.

 

[alex1122]

I usually run prime95 for 12 hours or more. I just start it before I go to sleep and leave it running overnight and into the next day whenever I get back to the computer. Usually comes out to about 12 hours maybe a couple more sometimes. If it runs for that long without errors then I consider it stable however, if I see programs or games crashing and prime passed, I usually back down a bit and try re-testing prime again overnight. Prime isn't the only way stability issues will show.

 

[MADMAX23]

Steps to test stability:

1) Run Memtest86+ 1.65 tests 5 and 6, 25 times each, then run 5 times the whole Memtest tests.
2) Run Prime95 24.14 blend test for at least 12 hours, although 24h or more are recommended.
3) Run Prime95 24.14 blend test for at least 6 hours with 3DMark2001 running at the same time in loop mode again and again for at least 6 hours too so that all your system gets stressed to the MAX.

If your system passes succesfully through those tests it can be considered 99,99% stable!!!

 

[govtcheez75]

I usually run for 48 hours at priority 10 (meaning that it's pretty much useless for 48 hours).