Funny problem (funny hmm, not funny ha ha)

[Wombat]

Got any fans plugged into the motherboard's fan supplies? Try unplugging them, I had a system where that was enough to restore stability.

[schmosef]

I'll check but I think they are all plugged into my power supply.

My PS has power leads specifically for case fans. It has its own thermal sensor and adjusts the speed at which the fans connected to those leads run accordingly. It works out to a pretty substantial noise reduction.

My CPU fan is connected to a regular power lead but has a sensor cable that connects to the CPU fan header on the motherboard.

This morning I was thinking that maybe when I installed the new cpu I moved some power cables around and maybe something is dangling too close to the Parhelia now. I'll crack it open when I'm back in the office tomorrow to take a look.

This is really frustrating. On the surface it would seem like a cpu upgrade from a 2800+ to a 3200+ is hardly worth it but I've noticed the speed improvement. When programming ASP.Net one has to do a lot of "compiling->testing->compiling->testing" and anything to increase the speed of a compile is worth it.

Anyway, thanks for the ideas guys. Keep 'em coming!

[G400SG16mb]

maybe your AGP bus is at 80MHz?

[schmosef]

My AGP bus is set to "default" in the bios. I assume that means 66MHz. I did try setting it to the lowest setting, 50MHz, just to see what would happen. It caused my PCI video card to run extremely slowly. But the problem with my AGP Parhelia was still evident.

[Nappe1]

Originally posted by schmosef
My AGP bus is set to "default" in the bios. I assume that means 66MHz. I did try setting it to the lowest setting, 50MHz, just to see what would happen. It caused my PCI video card to run extremely slowly. But the problem with my AGP Parhelia was still evident.

usually,
Default sets AGP based on dividers.
on 133MHz FSB divider is 2, 166MHz it's 2.5, in 200MHz it's 3

so for example, if you have FSB set to 146MHz, Divider is still 2 which means your AGP is running at 73 MHz (which is way beyond the spec.)

[schmosef]

Well My FSB is 200MHz so divide that by three and you get 66MHz. I'm not trying to overclock anything.

I just tried upping the AGP voltage in minor increments and it didn't help the problem either.

[schmosef]

Hmm... My +5V is low, about 4.5-4.6.

Could this be causing my problem?

Is it more likely my motherboard or Power Supply?

[Goc]

Could be both, but I would check the PSU first...

[Wombat]

3.3V is made by the motherboard from the 5V line, but 5V is made by the PSU. And in all but the most premium PSUs, the 5V and 12V are made from the same source.

ATX spec technically allows you +/- 10% of voltage, so you're pushing it. Maybe your motherboard is shorted and affecting your PSU, but it's more likely that the PSU is just being stressed out.

Could you, at least temporarily, run without your CD/DVD/extra HD drives? Maybe that will free up enough juice to try your CPU at full speed. If it does, then I'd rule out the motherboard as a source of your problem.

[schmosef]

Good idea. I'll try running without my CD, DVD, CDRW, and one of my hard drives, to see if there's a difference.

If there is a difference, does that mean my PSU is bad, or that I need a bigger PSU? I should think 480W is enough!

[Greebe]

most AMD mb's use the 12vdc rail to produce te cpu voltage

[Wombat]

Well, you haven't posted full system specs, so it's hard to say. 480W sounds like "a lot" but if it's poorly built, then it isn't much at all. Also, if you've got a lot of things running off of that circuit breaker, you may be underpowering the system.

[schmosef]

System Specs:

Motherboard->Asus A7N8X 2.0 DLX bios rev 1008
CPU->OEM AMD Athlon XP 3200+ (Barton core)
CPU Fan->Cooler Master Aero 7 Lite (set on max speed)
AGP->Matrox Parhelia 128MB (Cornerstone p1750 @ 1920x1440, Viewsonic P225f @ 1600x1200)
Slot2->ATI 9200 base PCI card (Viewsonic P225f @ 1024x768)
Slot4->Adaptec 2940U2W (pure SCSI system, no IDE, ATAPI, or SATA Devices)
Hard Drives->2 Seagate 10K Cheetahs
Optical Drives->Plextor 32x, Pioneer DVD, Yamaha CDRW
RAM->2xMicron 512MB DDR PC3200
Power Supply->Antec 480P
UPS->APC 1000XL

I have a USB scanner and printer hooked up too.

[schmosef]

Well, my problem seems to be solved.

Throughout the week my system became increasingly less stable. Finally, today I had a chance to swap the PSU and all is well!

Thanks for everyone's help. Much appreciated.