Any Mac Pro that suffers a logic board failure is going to be an expensive repair, only ones covered under the Apple Care will be covered, yet I don't think many die anyway. I already pointed out that he doesn't state what he's going to use the machine for, but that being said, the Mac Pro 1,1 is still a powerful machine. I've had one for almost a year, its been on 24/7 and I've had no issues with it, and its coming on 6 years old now.

It's nothing new that old hardware comes with a certain amount of risk, however how many Mac Pro 1,1's have you heard of dying? Have you ever used a Mac Pro 1,1? You can find them for sale all over Ebay and Craigslist, they are 'tanks' as someone else put it. I just came across another one of your replies in another thread where you are basically saying the same thing about old hardware. Buy an imac designed to reduce desk clutter, and place a big noisy box beside it. The thunderbolt raids are extremely noisy relative to the computer. Also have you ever seen one of those Promise enclosures? Many people hate computer noise, and Apple is always trying to build silent machines. I've seen many imacs where the display gets that purple cast around the edges within a couple years. Imacs have a lot of problems, and that display isn't so great. If you're not really going into any really heavy software, your problem is probably in one of those areas. The biggest things that slow the average user down are typically related to hard drive speed, drive clutter, lack of ram, and in gaming often the gpu. A logic board could be $600+ unless you find a salvaged one. Replacing the gpu (7300GT and X1900XT both had issues and either could die) roughly $200 or so for a Mac version of the 5770. Any significant repair is going to cost you quite a lot. The other issue I see here is that purchasing older hardware you're taking a risk.

Just buying an older tower is not an automatic fix here, and geekbench scores aren't going to help without identifying the current source of his problems. It can be ram, cpu, gpu, the hard drive, etc. The OP hasn't even given any real details on how he uses it, so there's no way to tell the source of bottlenecks in his current machine.

Five year old hardware isn't necessarily going to be smoother and more powerful.

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