Comparing Microsoft RemoteFX to VMware PCoIP

RemoteFX and PCoIP have similarities and differences, but the real battle between Microsoft and VMware's VDI protocols is at the hypervisor level; It's Hyper-V versus vSphere.

Now that Microsoft's first service packs for both Windows 7 and Windows Server 2008 R2 are available, the new Remote...

FX enhancements to RDP are available to the general public. Last week, I compared RemoteFX to Citrix HDX and discussed how RemoteFX would affect Citrix. This week, I'm going to focus on VMware, specifically, how RemoteFX will affect VMware View's PC-over-IP (PCoIP) protocol.

Comparing RemoteFX and PC-over-IP
From a technical perspective, Microsoft's Remote Desktop Protocol with the RemoteFX enhancements enabled is actually pretty similar to the PCoIP protocol. Both are what Jon Rolls, Quest Software's vice president of desktop virtualization products, calls "bitmap streaming protocols," as are HP's Remote Graphics Software and Virtual Network Computing (VNC). These bitmap-streaming protocols actually do 100% of their encoding on the remote host and transmit a series of "final" bitmaps to the client. So from the client perspective, it's almost like the client is watching a movie of the desktop that's being created in real time based on its activities.

The advantage of bitmap-streaming protocols like RDP with RemoteFX and PCoIP is that they handle multimedia and extreme graphics well, and they have very low client-side hardware requirements. But the downside is that they basically shift all of the processing over to the remote host, which leads to an increased CPU load on the remote host.

RemoteFX and PCoIP handle this increased load requirement differently. With RemoteFX for virtual desktop infrastructure (VDI), Microsoft requires the remote host to use a graphics processing unit (GPU) to perform all the bitmap encoding so it doesn't "waste" CPU resources on it. VMware PCoIP, on the other hand, does all of its encoding via the regular server CPU.

Which is better?
Which method is better? It depends. Microsoft RemoteFX requires an expensive GPU add-in card for servers, but you won't increase the overall server load. VMware can do PCoIP encoding with normal hardware, but at the expense of bogging down the server with users with heavy multimedia needs (which leads to fewer users per server).

Both protocols require a decent amount of bandwidth and aren't the greatest over the WAN, although PCoIP is actually more refined and better (or "less worse") than RemoteFX.

PCoIP, for example, transmits only regions of the screen that change from frame to frame. RemoteFX, at this time anyway, transmits entire frames. PCoIP also has a "build to lossless" feature where it can send lower-quality snapshots faster, whereas RemoteFX is limited to dropping entire frames when things get backed up.

Interestingly, both Microsoft and Teradici (the maker of PCoIP that licensed it to VMware) have announced that they'll release hardware acceleration add-in cards for servers later this year, so they'll both raise the bar to the same place at the same time.

Should VMware worry about RemoteFX?
The real story of the battle between RemoteFX and PCoIP is actually at the hypervisor level. It's a battle of Hyper-V versus vSphere.

For VDI environments, Microsoft RemoteFX is available only to remote desktops running on Hyper-V. Likewise, VMware View (with PCoIP) only runs on VMware vSphere. So if a customer wants to use RemoteFX, it has to be on the Microsoft stack, and if it wants to use PCoIP, it must be on the VMware stack. This means that we'll see very little switching from PCoIP to RemoteFX. Instead, Microsoft will just try to convince potential customers that their stacks with RemoteFX are just as good as VMware's stack with PCoIP.

So I don't think that VMware will "lose." (In fact, the company can now claim that Microsoft's RemoteFX bitmap-streaming approach actually validates what it has been doing with PCoIP for years.) But when it comes to a "win," that will actually go to the customers, as we now have another bitmap-streaming protocol choice.

Brian Madden is an independent industry analyst and blogger, known throughout the world as an opinionated, supertechnical desktop virtualization expert. He has written several books and more than 1,000 articles about desktop and application virtualization. Madden's blog,, receives millions of visitors per year and is a leading source for conversation, debate and discourse about the application and desktop virtualization industry. He is also the creator of BriForum, the premier independent application delivery technical conference.

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