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Guest RDP vs VRDP

Posted: 1. Sep 2009, 22:53
by Waylon McFlailin
I have a WinXP VM running in VirtualBox on RHEL5. I have configured the VM with a bridged adapter and to accept RDP connections directly, as well as VRDP access on the real interface. When I connect via VRDP and play a video, the performance is "ok" - degraded but not terrible. However, when I RDP connect "direct" to the VM on the bridged interface, the video performance is unusably choppy. The GUI response via the "direct" connection is just fine, it's just the video that is terrible. I realize the virtualization layer adds some overhead, but I wasn't expecting it to be this bad with video playback. Is there any tuning I can do to improve this?

Re: Guest RDP vs VRDP

Posted: 1. Sep 2009, 23:46
by Sasquatch
Even I have terrible video playback on native RDP, so it's not a VB issue. The problem is the Remote Desktop protocol itself. It sends bitmaps of the screen to the client and when you play a video, a large amount of data is generated and can cause slow playback like this.
I don't know how VRDP works exactly, but it seems that it uses a continuous stream of images, perhaps compressed or something, and that results in a smoother experience.

So, not much VB can do about, it's just the protocol that's causing this. Check the bandwidth that's in use, and the CPU usage on the Guest. Maybe that works too. My last guess is that MS build some restrictions in their RDP to make sure it doesn't take up so much bandwidth, and VRDP doesn't have that restriction.

Re: Guest RDP vs VRDP

Posted: 2. Sep 2009, 01:38
by Waylon McFlailin
You're right, RDP from native linux to native XP gives the same unusable behavior. Thanks.