Acceptable Voltages

[Yst]

So I had my Athlon 64 system with its six hard drives, Radeon 9700 Pro, three case fans and various bells and whistles and I was and am getting crashes to desktop and reboots during use (not just games which push the vid card's power reqs- firefox crashes intermitently as well). Occassionally, a reboot will result in an "Overclocking Failed" message at POST. The system is not overclocked, so I would tend to blame that on temperature or power issues. So I'm trying to evaluate whether it is one of those:

My CPU and case temperature are fine. It's a very well ventilated and cooled case and CPU temp sits at around 36 degrees celsius with case temp at 30 degrees. The CPU is using the heatsink/fan combo that came with the boxed retail Athlon 64 2800+ CPU. Memtest86 reported no memory errors, and the DDR266 I was using was working fine in my previous system. I upgraded to new DDR400, ran Memtest86 again, and no errors, so I don't see that it could be the memory causing reboots and crashes to desktop.

As I understand it, the CPU, the six hard drives, the large case fans and the Radeon 9700 Pro will all be drawing heavily off the 12v rail. So to be sure, I upgraded my Enermax 430W, which was speced for 20A on the 12v rail to an Antec TruePower550 ATX12V, which is speced for 30A on the 12v rail.

Currently, my BIOS and Asus PC Probe are reporting my +12v rail as operating at around 11.71.

+12V = 11.712
+5V = 4.95
+3.3V = 3.264

Is this within a reasonable range, or might this low +12v voltage be the reason for my reboots during use? Those figures do not appear to drop during heavy use (i.e., looping Doom 3 timedemos at max settings does not cause any visible lowering of those voltages, although it will crash or reboot the system after a random period of time).

So why am I getting 11.71 on my 12V rail using a 550W high-end Antec PSU speced for 30A on the 12V rail? And is that acceptable?

 

[dmw16]

Those 12V rails seem low to me. I think you may just have too much stuff. Six hard drives is a lot. Can you get dual power supplies?

 

[BW86]

yea those voltages are kinda low, but dont trust the bios. If your going to get a new psu bc your bios shows low voltages go buy a multimeter and try it yourself.

 

[Matthias99]

Originally posted by: BW86
yea those voltages are kinda low, but dont trust the bios. If your going to get a new psu bc your bios shows low voltages go buy a multimeter and try it yourself.

ding ding ding!

BIOS measurements are, until proven otherwise, *completely* unreliable in terms of absolute accuracy (and often even relative accuracy).

 

[TwoBills]

Your voltages/amps are fine. I don't think your reboot problem is power related. I would suspect the memory.

 

[Yst]

Unfortunately, I tend to agree that memory is my likely culprit, seeing as only it and power are universal enough problems to be associated with all my issues (Windows installer failing to find files resident on the disc, reboots during heavy use, crashes to desktop during any sort of use). That would be an extremely frustrating conclusion to have to come to, however, seeing as I'm already sitting here with four 512MB DDR DIMMs in my hands, none of which produce errors in Memtest86, and under all of them I face this crashing/rebooting problem. Buying another gig of DDR while having 2GB already would be kind of a financial heartbreaker. Especially seeing as I can't establish there's anything wrong with the existing DIMMs.

<sigh>

Every time I build a new system from independently purchased components, I swear I'll never do it again. And I always do.

 

[TwoBills]

Hmm, maybe you better stick a meter in your atx and confirm those voltages.

 

[Yst]

I'm using a cheap-ass multimeter, but I'm getting dead on 12V by its measurement on the 12V and dead on 5V on the 5V. One more reason to discount power as a probable cause. Back to the drawing board.

 

[TwoBills]

Could it be related to the video card? I'd try unplugging every thing except the bare minimum (1 stick of ram, vc, 1hdd) and go from there.

 

[thermalpaste]

11.7 volts is okay. For a stable overclocked system the tolerance limit is +/-5% for the 12 volts rail (11.4volts-12.6 volts).
Main culprits:
(1) memory.(but you said you ran diagnostic tests)
(2) windows-xp is a fuss pot, and is very sensitive to hardware changes in some cases. Disable the auto restart. my computer>properties>startup &amp; recovery>settings>system failure. Let me give you an example: I had a p-III 650 Mhz running at 866 Mhz by overriding the PLL settings using software. I had a dual boot with windows-98 and xp. When the PC was overclocked win-98 ran Sisoft burn-in wizard 600 times without any glitches, but windows-xp would keep restarting. People claimed that the software (CPUFSB) was incompitable with xp. But whenever the PC rebooted, the PLL setting never changed because of the warm-reboot. Despite of disabling this software after reboot the freq. remained 866Mhz and xp couldn't take it. (though this is a rare case.)
(3) a typical 7.2 drive (ATA) requires 0.7A to 1.2A when running. (0.75 for a 80 GB seagate barracuda).
6 drives means 6*1.2 = 7.2 amps approx.(this is only on the 12 volt rail mind you).
CAse fans take a measly 0.17-0.40 amps so that doesn't matter. say you have 10 case fans. that equals to 0.4*10=4 amps. Mobo processor RAM combo will take a maximum of 14AMPs(thats way to optimistic....) so we have the major components consuming about 25.2amps max(optimistic figure here)
So we are left with 4.8 amps for other components like DVD-RW, GPU et al. Use the multimeter in series with the 12 volt rail and check out the reading on the ammeter for an accurate figure.
The radeon is power-hungry. Try running your PC with a low-end video card which is frugal when it comes to consuming power and check the stability of your system. (this outta work)
OR Get yourself another PSU........

 

[TwoBills]

Originally posted by: thermalpaste

(3) a typical 7.2 drive (ATA) requires 0.7A to 1.2A when running. (0.75 for a 80 GB seagate barracuda).
6 drives means 6*1.2 = 7.2 amps approx.(this is only on the 12 volt rail mind you).
CAse fans take a measly 0.17-0.40 amps so that doesn't matter. say you have 10 case fans. that equals to 0.4*10=4 amps. Mobo processor RAM combo will take a maximum of 14AMPs(thats way to optimistic....) so we have the major components consuming about 25.2amps max(optimistic figure here)
So we are left with 4.8 amps for other components like DVD-RW, GPU et al. Use the multimeter in series with the 12 volt rail and check out the reading on the ammeter for an accurate figure.
The radeon is power-hungry. Try running your PC with a low-end video card which is frugal when it comes to consuming power and check the stability of your system. (this outta work)
OR Get yourself another PSU........

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My 160g seagate pulls .35a max/12v and the optorite cd/rw is 2a (5v and 12v combined) so I calculate 1.5/unit. Other people calculate 2a/unit (including opticals) which is probably more accurate, but let's stick w/my 1.5 number: (6) hdd = 9a. (2) opticals (guessing here) = 3a. The 1.5 number is way high, so that takes in everything else (like fans and video cards) that's not in the calc. So, we have 8 units x 1.5 = 12a on the 12v,which is more than enough. That psu that the op is using has 30a available, under load (which he has), so he should be fine.

The mobo, cpu, and ram use the 3.3 and 5v rails, mainly, so they're not in this calc. and the high 1.5 adverage number takes in anything I'm missing. The reason you need a strong 12v rail is to prevent a loss of amps on the 3.3 and 5v, which will happen when you reach a maximum point on the 12v requirements. The 3.3 and 5v will drop in order to provide more on the 12v, in an overloaded situation, causing cpu, mobo, and other data related stability problems.

I use the 1.5a/unit (unit = hdd and opticals) number in an attempt to calculate amps needed for a particular system, instead of the overused watts number. So, that's the formula that I came up with: 1.5 x units = amps required on the 12v rail. It's not entirely made up of whole cloth, but there might be a little spin involved.

Comments on my math?

 

[Yst]

Originally posted by: TwoBills
Could it be related to the video card? I'd try unplugging every thing except the bare minimum (1 stick of ram, vc, 1hdd) and go from there.

Bingo. To quote the manual (someone on alt.comp.periphs.mainboard.asus finally pointed this out to me):

"If installing the ATi 9500 or 9700 Pro Series VGA cards, use only the card
version PN xxx-xxxxx-30 or later, for optimum performance and overclocking
stability."

And of course I have...an early run 9700 Pro...

Swapped it with a GF4 4200 and suddenly everything works.

9700 Pro: everything from Firefox to XP itself crashes after a while, drivers fail to load half the time, weird boot errors.
GF4 4200: no issues of note.

How a vid card could cause all this, I have no idea, but it seems to be the case.

 

[thermalpaste]

Gf-4 Ti-4200 YUCKH!!!!!!!!!