Here’s a couple of key points on VDI scenarios:
- RemoteFX requires a GPU on the server. This GPU is then virtualized (a new capability of Hyper-V in 2008 R2 SP1) and presented to each VM just like any physical hardware component. What we don’t know at this point is how many VMs a single GPU will be able to support. Microsoft has said that they’ll eventually come out with sizing guidance and pointed out that the sizing is not based on VMs but rather the number of screens and pixels a specific GPU can support. And of course you’ll be able to add multiple GPUs to each physical server, either via the PCI riser card in the server chassis or via external PCI chassis that could house lots of cards.
- RemoteFX can use a custom chip (called an “ASIC”) on both the encoder and decoder side. This is conceptually similar to Teradici’s implementation of PC-over-IP but with one main difference. Teradici sells chips to hardware partners that they put into their own products. Microsoft has merely designed the chips which they’ll license to partners to be implemented in whatever ways the partners see fit.
Update: Brian Madden just published a follow-up email from the Teradici CTO, Randy Groves, who explained in details the technical issues related to the use of one or more GPUs on virtualization hosts. It’s a highly-recommended reading.