The older 2008 Apple Mac Pro tower computers use a crude and prone to vibration mounting bracket system to hold the hard drives upside down in the case.
When I changed to use an Intel SSD drive last year I had to fix the drive into place with cable ties to hold it up in the apple drive trays.
Last week I ordered a Corsair Force 3 240GB solid state drive to use as a Windows 7 boot drive and use the older 160GB Intel SSD just for OSX.
Fitting the second drive with cable ties wasn't possible as the front drive bay doesn't give you any access to get the ties in place so machined some brackets from 10mm aluminium and these screw into the side of the SSD drives and into two of the mounting brackets on the Apple drive trays. Its not the best solution as the drive is only held up on one side but it allows the fitting of a 2.5" SSD drive into bays 1 and 2 on the Mac Pro (3 and 4 have 1TB 3.5" normal drives fitted)
Drilling the side mounting holes for the SSD drives
The photo below shows the parts ready for assembly.
New mounting bracket next to SSD drive.
Corsair Force drive fitted to new bracket.
Intel SSD drive fitted to new bracket.
Since fitting the new drives and reinstalling both Windows 7 and OSX, the Corsair drive has failed with repeated IO errors. I tried both Windows 7 and OSX Lion and OSX Snow Leopard on the drive but they all failed after a few hours use. The drive has now been returned to ebuyer.com and just waiting to get a refund now!