Note regarding ATI X1900 XT with Mac Pro, Leopard

Question

To all who are experiencing any of the frequently reported problems with the hardware/software combination listed in the subject heading:
I purchased the ATI X1900 XT as an upgrade fro my Mac Pro in January. I never experienced any issues with the card in OS X Tiger, but several months ago I began to experience overheating issues in Windows XP (Boot Camp) when playing graphics-intensive games. The overheating caused visible graphics corruption/artifacts, graphics system resets and even spontaneous system restarts. The frequency and severity of these symptoms actually increased over time, leading me to believe that the card was either defective or that the overheating was causing degenerative/cumulative damage to the graphics hardware.
I recently upgraded to OS X Leopard, and all **** broke loose. Immediately after upgrading, I began to experience frequent graphics corruption/artifacts (in the form of spurious horizontal lines), system lockups/freezes and spontaneous system restarts. None of these issues were present in Tiger. The system became completely unreliable and essentially unusable.
It was initially a popular belief that Leopard's graphics drivers were somehow buggy or incompatible with the X1900 XT. After my experiences, I don’t believe that’s the case. I think that the issues reported are symptomatic of hardware, not software problems. Leopard is merely a catalyst. Leopard's increased leverage of OpenGL stresses the graphics hardware in ways that Tiger did not, causing an overall increase in graphics hardware temperature. I believe that the glitches/artifacts/system freezes/restarts that I experienced were not due to buggy drivers, but due to the graphics card overheating as a result of the increased load placed on it by Leopard.
I brought my X1900 XT in to my local Apple store today and asked for a replacement. Fortunately, they had one in stock, and they gave me a new card on the spot. The technician was apparently well aware of the issues, and mentioned that they have had a lot of similar problems with new iMacs.
Since installing the new card, I have experienced no graphics corruption, system freezes or spontaneous system restarts, either in OS X Leopard or in Windows XP gaming.
I would urge anyone who is experiencing problems with the X1900 XT (in either Windows or OS X) to have their card replaced by Apple - assuming that their card or system is still under warranty, that is.
I suspect one of two possible scenarios is true:
Theory #1: The Rev 1 X1900 XT is inherently flawed and has problems with overheating, which is exacerbated in OS X by upgrading to Leopard. Due to Leopard's greater leveraging of OpenGL, there is increased thermal stress placed on the card relative to Tiger. The overheating is evident in Leopard as graphics corruption/artifacts, system lockups/freezes and spontaneous restarts. The Rev 2 X1900 XT has (theoretically) corrected the problems inherent in Rev 1.
Theory #2. The thermal management system of the X1900 XT (all revisions) is inherently flawed. The card will slowly cook itself over time, and the effects are degenerative and cumulative. As the age of the card increases, so will the occurrence of graphics corruption, system freezes and spontaneous system restarts, especially when playing graphics-intensive games or running OS X Leopard.
I sincerely hope that Theory #1 is the case. I’ll be watching my system closely as I continue to use the new card, and hopefully there will be no further problems with overheating.
If theory #2 turns out to be true, then Apple has a huge PR nightmare on its hands, as each X1900 XT for the Mac is essentially a ticking time bomb that will self-destruct within months of purchase.
The funny thing is, this isn’t the first time I’ve had graphics card trouble with one of Apple’s “professional” towers. I bought a G5 several years ago when they were first released. I had problems with the stock nVidia graphics card in the form of what came to be known as the dreaded “black screen of death.” This became a commonly reported issue, experienced by many owners of the G5 in its first revision. Apple replaced my card and the problem never reoccurred. I’m hoping that I’ll be as lucky this time around.
I think it’s apparent that Apple’s batting average with graphics cards isn’t exactly stellar. It’s curious, considering that Apple offers a very limited selection of graphics options for their towers. One would think that by Apple only offering 3 graphics options, they would be able to have fairly tight control over the quality of the hardware, and plenty of time and resources to devote to testing. Unfortunately, I’ve had more graphics hardware-related problems on my Macs than any PCs I’ve ever used. That’s embarrassing, and Apple needs to do much better than this.

Answer 1

I replaced my G5 Quad with a Mac Pro 8-core. The Mac Pro's thermal design is far superior to the G5's. The G5 Quad's liquid cooling system has a much bigger task (IBM doesn't publish the thermal dissipation numbers on their PPCs but I suspect they are high) than the more efficient Intel Xeons. The G5 liquid cooling units are troublesome and the issue is something I think Apple is quietly solving by replacing failed liquid cooled G5's (that are still under warranty) with Mac Pros (a very smart PR move). My primary concern when I switched to a Mac Pro was issues with the X1900 XT graphics card failure rates posted on the web and in these discussions. The very latest generation of the X1900 XT (July 2007) are reported to be more reliable. Many G5 owners are still reporting failed cards. Given the much higher thermal environment and the remarks in this thread, I can now see why. The interior of a G5, especially Quad, gets too hot for this ATi card. I had the nVidia GeForce 7800 GT in my Quad. That was a very good card. Still, the issues with the ATi x1900 XT may indeed be a thermal design issue that AMD may need to either address directly, or turn to a 3rd party solution.
I installed a 3rd party cooling alternative, Arctic Cooling's Accelero S1. It's a passive system that replaces that hairdryer fan with a large heat sink. The package includes upgraded heat sinks for the power regulator (much beefier than the stock), and for each memory chip. The heat sink is a large conductive cooling assembly that uses 4 heat pipes. The vendor claims that using this system increases the case temperature by 1°C, which is easily handled by the system cooling system. So far, their claim appears to be valid. Since there's no longer a fan, you can imagine how quiet the system has become. The only installation hitch is that the black support clips were made for the PC version and the Mac Version adds a beefy support rail on the spine of the card. The workaround is to trim off the lower tang of the clips so they just rest against the support rail.
After reading this, I'm tempted to add the "Turbo" option, a couple of high volume low speed fans that fit on the radiator. I'm trying to "stress" the system by running SETI@Home 24/7 while doing all the other work to see how hot and how loud I can get this system. So far, no disappointments. This is the quietest workstation I've ever worked on. Even when "hot", the fans are not loud. The passive cooling system seems to work very well. I left Star Wars-Empire At War up and running in the menu for hours one day and it didn't seem to suffer from any ill effects. I have owned this system for just over a month. I will add more thermal load after I crank the system memory up to 24 or 32 GB. If there are any real cooling issues, I will find out about them next summer. I really dread the prospect of plunking down another $2k for the nVidia 4500 FX (I really don't need the 3D audio support) to get comparable video support.