Tim, one of the Parallelsteam members, made a post about new Parallels Desktop builds they’d like Mac Pro/iMac owners to try out:
We are on the way to deliver a Parallels Desktop for Mac version that supports Mac Pro and iMac Core 2 Duo without RAM limitation.
There’s an internal build that is available for early testing which can be downloaded from here.
Please don’t forget to backup any sensitive data on your Mac before proceeding to evaluation.This version does not limit Mac Pro and iMac Core 2 Duo RAM amount and removes the limitation set by previous update. Please don’t forget to restart your Mac after installing this update and ensure that RAM reverts to its original amount.
As usual, we’re extremely interested in your feedback about this build and any issues you might face.