Here is the scoop. Yes it will run Einstein. However it runs them pretty slow. I am going to go out on a limb here and say that Einstein must be intensive on the GPUs ram as I have a Zotac 430 GT PCI-e with 2048 MB of Ram and it is running 10x faster than the PCI version which only has 512 MB of Ram. I am not running any optimized app or anything.
I have 2 PCI and 1 PCIe in the same rig and have dedicated a core to them for running the Einstein as they are grabbing .20 CPU per card to run it.
I hope this helps. If you want any other information or want me to test them in a different configuration just let me know.