1st-gen Mac Pro problems... Is it the GPU?

A little background: I'm running a first-generation Mac Pro with a PCI-Express GPU connector. My card is an ATI Radeon X1900 XT 512 MB. Originally, the card was giving me all kinds of weird artifacts during 3D gaming (World of Warcraft) and after much cajoling over the phone I was able to get Apple to replace the card under warranty. This solved the problem. Now I am running the revised edition of the same card.

Flash forward to a year or so ago. Out of nowhere, the computer has begun shutting itself off. It doesn't happen every day. It doesn't even happen every week. I'd say once a month at the worst. But still, out of nowhere it just powers down. In addition, when running pretty much ANY full-screen app, such as a game that involves 3D graphics, the screen simply blanks out while the rest of the computer continues to function.

When this behavior began, I took the computer to the genius bar, thinking it was the power unit. They ran tests and the power unit came up peachy.

However, I have begun wondering if perhaps it's the GPU that is to blame. I had this problem with my previous computer, a Dell desktop. It would shut the computer down during certain games, and when I bought a new DVI-based LCD monitor to replace my CRT, it fried the connection between the GPU and the logic board and bricked the computer.

So after all that, my question is this: Do you think I would be able to solve my issues by replacing/upgrading the GPU? I could theoretically buy a new iMac this summer when they're updated, but I really think my current computer is still filling my needs. I don't really game on it anymore, and after I recently doubled the onboard RAM it really has been able to chug along nicely in performing its other duties.

Here is the card I was looking at as a replacement:

MACPalace, Inc. - 661-4724-Video Card, NVIDIA GeForce 8800 GT 1st Generation 512 MB Mac Pro 2-2.66-3 Ghz A1186 MA356LL/A

or possibly:

MACPalace, Inc. - 661-4911-Kit, Video Card, NVIDIA GeForce 8800 GT, 512 MB and Cable

(I'm not sure how they're different)

Do you think this would solve the issue? I'd hate to sink another $200 into an old computer and not help things, but if it DOES solve the issues, then I could easily get another 2 years or so out of the computer, which would wind up saving me money since when I DO replace it, I'll get more computer per dollar, PLUS I'll be able to sell this as a functioning computer and not a defect.

Thanks.

Doctor Suarez said:

Flash forward to a year or so ago. Out of nowhere, the computer has begun shutting itself off. It doesn't happen every day. It doesn't even happen every week. I'd say once a month at the worst. But still, out of nowhere it just powers down. In addition, when running pretty much ANY full-screen app, such as a game that involves 3D graphics, the screen simply blanks out while the rest of the computer continues to function.

Click to expand...

My first thought after reading your post (and factoring that the computer is a 1st gen. Mac Pro...i.e. 5-6 years old))...is that maybe your computer is overheating & shutting itself off automatically.

Have you ever opened this thing up...and checked it out for dirt/fuzz? Many areas can get clogged...such as the fans & the cooling fins on the cpu heat sinks (including the fan on the video card).

- Nick

I recently cleaned it out during the RAM install, which wasn't that long ago. It was dusty, but not spectacularly so. I will give it another cleansing and see if that helps. Still, I would love to hear more answers about other potential problems.

Doctor Suarez said:

I recently cleaned it out during the RAM install, which wasn't that long ago. It was dusty, but not spectacularly so. I will give it another cleansing and see if that helps. Still, I would love to hear more answers about other potential problems.

Click to expand...

If you didn't already...check the large fan(s) at the back of the Mac Pro...AND (with a flashlight) try to look thru the cooling fins of the cpu heatsink. If you can't see thru them...they're blocked.

The issue may not be dirt/fuzz buildup...just trying to make sure 100%, so we can cross this possibility off the troubleshooting list.

- Nick

Will do. Just restocked on air canisters and will do a full cleaning later.

However, assuming that's not it, what else could it be?

Doctor Suarez said:

Will do. Just restocked on air canisters and will do a full cleaning later.

However, assuming that's not it, what else could it be?

Click to expand...

Computers usually don't just "shut-off" randomly...and after a given period of time can be turned back on and they work normally...unless something like over-heating is the issue.

- Heat builds up>>temps increase>>temps hit critical>>computer shuts off.
- Computer cools down>>computer can be turned back on>>computer acts normally for a while.

So sticking with the over-heating theme...other than being dirty inside...are you sure all the Mac Pro's fans are operating properly?

- Nick

I believe they are. I'm running iStat and it lists the fans as spinning.

It's not that I don't think something is overheating, my question is more whether it's simply dust or a certain component might be overheating for another reason.

But at what speed are the fans rotating? Cool late autumn AM down under and all fans between 499/699rpm. Maybe SMCFanControl may help but suggest Nick's thoughts may be the go. Dust collects in particular over the DVR, clogs the from fan blades, rear main fan and memory cage fan.

Perhaps a 1" paint brush would be the go. At least annually strip my Mac Pro down, remove all the fans and give them a real good clean out. Front fan always seems the worst.

Now that I'm home I can tell you: Power supply and exhaust fans: 599 RPM. CPU and HD/Expansion, 499 RPM.

About to shut down and do a thorough cleaning... or as thorough as I dare.

Doctor Suarez said:

I believe they are. I'm running iStat and it lists the fans as spinning.

It's not that I don't think something is overheating, my question is more whether it's simply dust or a certain component might be overheating for another reason.

Click to expand...

I guess if I was to go out on a limb...you could consider the power supply as well.

The bottom line is...we can mostly only guess at what the problem may possibly be. Without known "good" parts to swap for potentially bad parts...there's no way to know for sure. The alternative is to take the computer to a repair shop...and pay BIG BUCKS for troubleshooting & repair.

If the video card was the problem...then you would probably have one of two situations:

- no video whatsoever
- video artifacts or "glitchy" video (lines across the screen, pixelation, wrong colors, etc.)

You also mentioned that the problem seems to happen mostly when you are pushing the computer hard. Which heats the computer up more than normal (e-mail & web surfing)...and if the computers cooling system is not working efficiently and/or if the computer is in a warm room...the computer may overheat.

I've given all I can give...good luck!

- Nick

Nick may in fact win the cupie doll. While it's only been on for a few minutes, I'm already noticing a difference.

To recap:

Shut the computer down and opened the side panel. The front fans were actually very clean. However, the GPU, while it LOOKED clean, spit out a pretty sizable dust bunny under air pressure. It was hiding in the large white fan/heatsink component on top of the card. In addition, I was able to scare a few dust bunnies out of the rear fans that service the RAM bays.

Turned the computer back on and it's operating much more quietly now.

I didn't remove the necessary parts to access the CPU heatsinks, but according to iStat they're running at about 90 degrees F, so my guess is that's relatively normal.

If it conks out later, I'll see what kind of dust accumulation there is. For now, however, the much, MUCH quieter operation is a good sign.

Thanks, Nick!

Doctor Suarez said:

I didn't remove the necessary parts to access the CPU heatsinks, but according to iStat they're running at about 90 degrees F, so my guess is that's relatively normal.

Click to expand...

This was going to be my next suggestion...if you had not found any dust/fuzz...which was to monitor your temps (often & closely) to determine any trends.

I have quite a bit of experience with used computers (I'm not a computer professional...just a serious hobbyist)...and the first thing I do with a used computer (new to me)...is inspect it for dirt/fuzz buildup...and clean as necessary.

With the "shut-off" issues you described...it sounded like over-heating could be the problem. Hopefully what you found was the major stuff...but I wouldn't underestimate how much dirt/fuzz can accumulate in the cpu heat sink cooling fins.

Please keep us updated...good or bad.

- Nick

Will do, though if you don't hear from me it's likely that things went swimmingly.

Right now I'm just enjoying the mild hum that has replaced the high-speed whine.

Doctor Suarez said:

Right now I'm just enjoying the mild hum that has replaced the high-speed whine.

Click to expand...

That's a good sign!

- Nick