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Computer stable?

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December 11, 2008 10:53:00 AM

I have a new home built system:
-AMD Quad 9950 Black Edition, with a Noctua NH-U12P heatsink
-Gigabite GA-MA-790X-DS4
-2x 2Gb DDR1066
-Thermaltake 750W toughpower modular
-ATI X800XL (I ordered a HD4870, but it was defective..., waiting for a replacement)

Anyways, I wanted to test stability using OCCT stress test. The result is that it always fails after about 1-10 minutes, although there is no overclocking, and the temps are stable at 45 degrees (Should be stable...). I get error code 4: Calculation error.

Other stress test pass with high colors.
I have seen in other forums not to stress, as sometimes OCCT will bug, so it's a software, and not hardware problem.

What did bother me is that some time ago, my HD4870 fried after my PSU tripped, so I wanted to monitor my power supply, during the stress test. My Vcore and 5V is rock solid stable, the 3.3 is alright (bit of fluctuation), and the 12V fluctuates a lot.

So here are my three questions:
1 - Should I be worried about OCCT errors? Can I just shrug it off to software bug?
2 - Is my power supply stable enough for my components? Is what I am seeing alright?
3 - Even if what I am seeing is OK, should I expect this kind of behavior from a High-End PSU? It's supposed to be very good quality.

Thanks!
PS everything is up to date, bios & everything

Pictures attached




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a b à CPUs
December 11, 2008 11:29:29 AM

Down load Prime95 and run Small FFT for ~ 8+hrs and see. Also you might want to check your PSU if the voltages on +12 changes a lot. Could be a very good cause. Imo, replace that PSU ASAP.
December 11, 2008 12:49:21 PM

No offense, but could you justify your "Imo, replace that PSU ASAP"? What is it you are seeing as an imminent threat to my system exactly? I'd be glad to do as you say, but I'd also like to know why.

The changes I'm seeing are 0.1V, so it's acceptable for the ATX, right? Is the fact that it is oscillating a tell-tale sign of death, even though it works?
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a b à CPUs
December 11, 2008 1:37:22 PM

That's only 100mv !!!
Even the best power supplies in the worild have a tiny amount of ripple.
Typically the 12V rails are 120mv to 150mv. So what you are seeing is that ripple.
So I would not be concerned with it.
As for software, Shadow nailed it! Use prime95 it's the best and will stress your system!
Hope this helps.
December 11, 2008 1:46:08 PM

Quote:
That's only 100mv !!!
Even the best power supplies in the worild have a tiny amount of ripple.
Thanks for your input.

Just curious though, isn't the "ripple" supposed to be fluctuations in power over a millisecond time period? Like noise? What I'm seeing is more of a power fluctuation on a 30 second time scale...

Or I could be wrong :pt1cable: 

But as long as my PSU seems fine, I'm happy!
a b à CPUs
December 11, 2008 1:52:56 PM

also run memtest86+ to make sure it's not anything memory related...
December 12, 2008 8:26:39 AM

I ran prime95 in mixed mode, and after 30 minutes or so, one of the workers stopped due to a round-off error. This happened 3 times.

So I guess there is definitely something wrong. The test was in mixed mode (FPU+RAM), so I tried the small FFT test (FPU only), and the test ran overnight for 8 hours with no problems. Guess this probably means the culprit is the RAM...

I'm going to run a Memtest86+ tonight to see.

I'm not sure whether or not I hope my ram is defective :sweat: 
a b à CPUs
December 12, 2008 1:38:12 PM

if you get errors with memtest you could increase the volts a little or loosen the timings, it might make it stable...

run memtest for several hours though, overnight if possible, to get multiple clean runs. The errors might not show up on the first try.
December 12, 2008 2:02:34 PM

Could you link me to a topic or thread about that?

Why would I change the voltages if I am not overclocking or anything?
I know DDRII specs are supposed to be 1.9V, but PC8500 is usually 2.1-2.2V right? Do I have to do this myself, or is my mother board smart enough for that?

For info, I have this memory: OCZ Reaper, 2x2Gb PC8500 (rev2)
And my mobo is an Gigabite GA-MA790X-DS4

Is there anything else I should know about memory stability, other than the obvious? My system works quite well, except for an occasional stress test failure, so probably only tweaks.
a b à CPUs
December 12, 2008 2:14:12 PM

JEDECs normal voltage for DDR2 is 1.8V. DDR2-800 is usually rated at 2.0-2.2V, DDR2-1066 is pretty much the same, maybe slightly more. But some DDR2-1066 modules can't even reach their rated speeds no matter what voltage is used.
and yes, you'll need to change it yourself in the BIOS. The mobo defaults likely to something slower and lower voltage, so it might cause some instability.
a b à CPUs
December 12, 2008 10:05:43 PM

@OP: I mis understood the question. You will NOT need to replace the PSU.
December 14, 2008 7:26:49 AM

Thanks for the replies.

Several tests using memtest86+ revealed that one of my two PC8500 sticks couldn't take 533Mhz settings.

Running it in PC 6400 fixed the problem. Apparently, they were PC6400 sticks to begging with, but were supposed to be overclockable to PC8500.

I have a few questions about ram now, but I think I'll go create a new thread, To ask questions about timings and such (but if you have any clue now). My mobo sets all these settings itself, but I manually changed the frequency mode (533 -> 400)
In PC8500, memtest displays the timings as 5-3-3-3-26; BIOS Voltage:2.160
In PC6400, memtest displays the timings as 5-5-5-15-41; BIOS Voltage:1.960
Aren't the PC8500 timings WAY too aggressive?

Anyways, I want to thanks everyone. You've helped me pinpoint the problem and solve it. But more importantly, I sleep better at night now :sleep: 
December 14, 2008 8:36:16 AM

well that's why! 5-3-3-26 (whats with the extra 3? oh do you mean 13?) is an extremely unbalanced timing to begin with, and nigh impossible even with 800mhz! manually set the timings to 5-5-5-18 and im sure it will pass memtest at 1066 or "PC8500" as you call it. then just lower it to 5-5-5-15 and one notch at a time till it fails stress testing...
December 15, 2008 6:46:26 AM

Alright, I'll try.
As for the extra three, I'm really just reporting what memtest said (which looked odd, I admit), but there are indeed 5 numbers (instead of the usual 4), and it displayed:
533Mhz: 5-3-3-3-26
400Mhz:5-5-5-15-41

I'll try to change the timings again, but I'd like to test the stability of the current 800, as OCCT still gave me an error, but prime95 seems stable. Guess it's all about tinkering now.
December 15, 2008 7:29:50 AM

yeah they are pretty retarded timings... im not surprised at all that failed. 0% chance of success in my books...
December 15, 2008 7:54:57 AM

Just how retarded are we talking about though? Because even with these timings, the computer worked fine, it took OCCT 10 minutes to fail, and prime 95 about 1H.

One would have though the computer wouldn't even boot!
a b à CPUs
December 15, 2008 8:32:08 AM

It shouldn't even boot with the 4th number as a 3. Something's definitely wrong there. Ignoring that, it is possible that they are almost stable at something like 5-3-3-26, as although those are odd, they are almost doable. I'd go for something like 5-5-5-18 though, as stated above.
December 15, 2008 8:41:07 AM

Thanx for your reply, I'll try that
December 15, 2008 8:45:54 AM

5-5-5-15 should also be attainable.
!