Upgrade to SSD drive with PT 10?

[mjbarry]

I just inherited my wife's late 2009 iMac. I'm going to upgrade the RAM to 16 so I can run Pro Tools 10.latestversion on it. I have PT 10 for PC but my PC has fan noise and the iMac is virtually silent, so I'm going to use the iMac for PT only.

I'd also like to upgrade the internal hard disk to an SSD. If I do this, is it possible that the system would then be running too fast for version 10 of Pro Tools? I am going to shift the MacOS back to 10.8.5.

I'm not that familiar with Macs, and I've seen this happen on PC's when there is older software running on a new OS and a fast machine.

Thanks!

Mike