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cgc · Jan 12, 2012, 01:15 PM

My beloved 2006 MacPro (w/ 2 x 2.66GHz Xeon 5150s) locked up after a bit or Portal 2 playing. I could see the top 1/10th of the screen, the mouse worked fine, but the bottom 9/10ths were FUBARed and mostly black with some white. Everything was blocky, not looking like noise per se.

I restarted and the screen looked normal but after about 45 seconds the spinning nondeterminate progress thing froze. I waited a bit and after no change I restarted again. Same thing. Did this two more times then zapped PRAM with no change. Took out memory in pairs with no change but then I noticed my CPUA and CPUB (#2 and #3 LED from left on motherboard) were lit red. I looked online and saw a SYS-RST has fixed this with others so did that to no avail. Tried booting from CD and at same point it froze again. Booted to single user interface and ran fsck w/ no errors but when it tried rebooting it froze in the CLI (right after loading Parallels plugins if that means anything).

Finally broke down and took out nVidia 8800GT and replaced it with my wonderful nVidia 7300GT but also removed my #2 and #3 hard drives and sleds. System booted up like a champ.

My question is what do you think is bad? I'm asking this because the video was only bad once. My thoughts are it could be two things:

1. Bad GPU
2. Bad PSU

For option #2 I'm thinking the GPU does something to draw power at 45 secs-ish into boot; the much less powerful nVidia 7300 doesn't cause the problem as it draws less power. How would I check the PSU or GPU to be certain without having an extra Mac or PSU laying around? Thanks.

reader50 · Jan 12, 2012, 02:06 PM

Add more drives, bus-powered USB / FW peripherals, etc. Increase the PS load with something other than a GPU to see if anything happens. You can reach at least 5 drives, 6 if you remove the #1 optical.

Install a distributed computing app to max out the CPUs. They're good power users too. Avoid a DC app that uses GPU acceleration.

angelmb · Jan 12, 2012, 02:43 PM

I bet it is the 8800. You can find topics about dead Mac 8800GT here (searches are not working for me right now) or at the nVidia boards; it happened to me too. I did the bake trick (in a nutshell, putting the nVidia inside an oven for some time in order to fix failed solder joints, there are videos about this) and it worked, died again, did the trick again and worked again… I got bored of doing that once and again and ended buying the ATI 5770 which still is a excellent performer for a Mac Pro 1,1 like ours.

My beloved 2006 MacPro (w/ 2 x 2.66GHz Xeon 5150s) locked up after a bit or Portal 2 playing. I could see the top 1/10th of the screen, the mouse worked fine, but the bottom 9/10ths were FUBARed and mostly black with some white. Everything was blocky, not looking like noise per se.

Kind of this?

I restarted and the screen looked normal but after about 45 seconds the spinning nondeterminate progress thing froze.

Same thing happened to me:

And a video I took that day… 180 Kb on size.

http://dl.dropbox.com/u/1763527/halfthefun.mp4

cgc · Jan 12, 2012, 07:14 PM

Originally Posted by angelmb

I bet it is the 8800...And a video I took that day… 180 Kb on size.

http://dl.dropbox.com/u/1763527/halfthefun.mp4

Exactly. I have my three HDDs, extra keyboard and mouse connected, Logitech Headset, two iPods, and a USB thumb drive connected and am running Parallels 7 while running HandBrake doing a conversion, a Time Machine Backup from drive 1 to 2 and a large file copy from drive 1 to 3. Got it up to ~230 watts according to iStat Menus which is a 1/5 of the PSUs max. If you swapped your 8800 and your symptoms were the same as mine then I'll bet you're right and my 8800 died.

While it sucks something failed I was hoping it would be the video card so at least the replacement 5770 will be an improvement...a replacement PSU would be no difference/benefit and probably cost more than my MacPro. BTW, if my MacPro did die I was considering replacing it with a Mac Mini w/ discrete GPU as it's essentially the same as my MacPro in terms of speed. Sad but true (according to BareFeats).

cgc · Jan 12, 2012, 07:36 PM

I was looking for a GPU to potentially replace my 7300GT (ugh) and was curious if anything new is coming from CES. The 5770 seems great, up to 70% faster on some tests vs 8800, lower power consumption, quieter, etc. but hate to pull the trigger on 5770 is something's coming out soon. My 7300 is acceptable so I'm not in a rush. Any opinions? Oh, I play MS Flight Simulator 2004 in Parallels, do Aperture, play Portal 2 in OSX and other minor stuff. I read ATI's cards are much better when using Aperture than nVidia's. Thanks again.

P · Jan 13, 2012, 04:29 AM

AMD is launching the 7000 generation now, using a completely new architecture called GCN. Only the top card, the 7970 is out now (at a silly price), but the mid-range cards should come.

angelmb · Jan 13, 2012, 07:16 AM

Do we know if those new AMD 7000 GPUs would work on a Mac Pro 1,1 ?

P · Jan 13, 2012, 09:14 AM

Of course not. We don't even know if there will be Mac drivers for it. The perennial rumors say that the next Mac Pro will get a Radeon 7970, which should imply drivers, and there are supposedly signs of it in 10.7.2 drivers, but EFI compatibility... Who knows. The new 7700 series looks like a pretty nice midrange card, though.

cgc · Sep 4, 2012, 04:30 AM

After waiting for a new GPU to be released to either drive the cost of the ATI Radeon 5770 down or replace it altogether, I decided to try to fix my nVidia 8800GT.

Following directions posted online, I removed the heatsink/fan assembly and baked the card in the oven for 10 minutes at 300F, then another 10 mins at 385F or so. After letting it cool I put some thermal paste on it and popped it back in. Seems to be working but only time will tell.

SierraDragon · Sep 4, 2012, 03:15 PM

Wow. Let us know if the fix holds.

cgc · Sep 18, 2012, 10:51 AM

The baked 8800GT worked perfectly until about ten minutes ago when it died. I'm back on my 7300GT until I buy a new computer.