I had all sorts of issues with my Mac Pro yesterday. It's one of the first generation Intel towers, and over the last couple of months, I have been seeing the video card get very hot. After installing Leopard, the card has actually been overheating to the point where I see artifacting on the screen. If I run Spaces for any extended amount of time, the machine locks right up. It's got an ATI Radeon X1900 XT card in it, and it seems these cards are prone to overheating. Using iSlayer's awesome iStat menus (pictured above), I watched the Northbridge temperature in the machine go North of 170 degrees F.

My first inclination on this overheating, since it's something I had only started to see over the last couple of months, was that the video card cooling system might be clogged with dirt. I took the machine apart last week to put some RAM in, and cleaned the card, which was, in fact dirty. However, this did not make the problem go away. Yesterday, I stayed home from work, so I was using the tower all day. Sure enough, last night it started overheating. I searched on Google a bit, and it seemed that most of what I found were references to MacBook Pro's overheating. Thankfully, one of the solutions employed to fix that issue on the laptop also solved my issue. There's an excellent piece of software named smcFanControl. It lets you manually control the fans in your machine. The stock fan settings in my Mac Pro seemed to be around 500 rpm. That was clearly not enough to cool my machine, which also has 3 SATA internal drives in it. I bumped (no pun) the fan rpm's for two of the fans up to 750 rpm. The cooling issue seems to be completely solved. I highly recommend both iStat menus and smcFanControl to other Mac Pro owners.

Also yesterday, I noticed a strange constant read pattern from the drive bays. Some of my apps were lagging. I would type something into an iChat window, but the text wouldn't appear for several seconds. I spent some time with the Activity Monitor, and couldn't find an obvious culprit. So I rebooted my machine from the Leopard disk and ran Disk Utility. As is sometimes the case, it found a ton of errors that it coud not repair. My theory became that all the crashing from the overheating problem was slowly damaging my hard drive file system. Not the physical drive, but the directory information on it. In the past I have used Disk Warrior to fix this issue. Currently, Disk Warrior is not compatible with Leopard in that it has issues if you run it while booted from a Leopard disk. Laziness paid off in that I have not upgraded the external utility disk I use for such tasks. I booted from that disk (Jeter) ran Disk Warrior, and fixed all of the issues. I recommend keeping an external disk with Tiger on it for such ocassions until the verious troubleshooting vendors update their software, and I highly recommend Disk Warrior.