I've been an unashamed fan of the old "cheese grater" Mac Pro due to its sturdiness and expandability. Yes, they're not the most elegant bit of kit out there but they are well built. And most importantly for me, they are expandable by plugging things inside the case, not by creating a Gordian Knot of hubs, Thunderbolt cables, USB cables and stacks of external disks all evenly scattered around a trash can. Oh, and they're designed to go under a desk. Where mine happens to live, right next to my dual boot Linux/Windows development box.
Mine is an early 2009 model, so basically the third-to-last iteration of the cheese grater design. It's a bit of a Frankenmachine in the sense of it having been refurbed from bits of an early 2009 Mac Pro (the chassis) and bits of a 2010 Mac Pro (the quad core CPU module). None of this was my doing, I bought it like that - yes, it's the box that came with the "interestingly mounted" SSD.
It replaced an even older six-core Mac Pro that was in turn a replacement for a 27" iMac and has done a pretty stellar job for four years. It's not overly taxed as I barely ever run games on it - my development PC also fills that hole - but it was getting a bit long in tooth. I didn't want to replace it with the current, utterly non-expandable Mac Pro so the decision was between migrating completely to a Windows/Linux PC or try to squeeze some more life out of the old warhorse. Most of the software I use is dual-licensed or -licensable for Windows and Mac, so that wouldn't be a big issue, but I wasn't overly keen on migrating music libraries, photo libraries and other assort large amounts of data.
In the end I decided to spring for a CPU upgrade and I'll probably get a bigger SSD for my home made Fusion Drive as well. There are plenty of sellers who'll upgrade the CPU tray for you - I picked macmotive on eBay, based on the feedback. He sent me a CPU tray fitted with a 6 core Xeon running at 3.33GHz and 32GB of RAM, as a replacement for my 4 core 3.2GHz Xeon with 16BG RAM. Fortunately changing the CPU tray on a cheese grater Mac Pro is a very simple undertaking - pull out the old tray, push in the new. I already had the upgraded 2010 firmware in mine so no additional changes needed to be made.
For those who haven't had a Mac Pro apart, this is what a CPU tray looks like:
The whole thing connects to the backplane inside the Mac Pro. Basically, changing out the CPU takes less time than crawling under the desk and opening the case.
So I went from this:
The performance improvement is noticeable after the upgrade as soon as CPU intensive tasks come into play, especially with photo or video editing software. From that perspective the upgrade is money well spent and it will hopefully extend the useful life of this machine by a few more years.
While I'd guess that upgrading the processor on the tray would've been DIYable, I'm happy to support a cottage industry that keeps these older, still powerful machines alive.