virtualbox.org

Hi.

I am running Virtual Box 3.0.4 on Windows Server 2008 R2.

The guest os is Windows 7 64bit with the guest additions installed.

I have the experimental 3D support disabled.

When connecting with VRDP the CPU will spike from 3-5% to approximately 35-40% even though the VM isn't doing anything. As soon as I disconnect the VRDP session the CPU drops back to idle again.

As well, it seem the bandwidth usage is pretty significant when doing a RDP session.

Any ideas on what could be causing this?

As well, what is the bandwidth usage one should expect with vrdp?

thanks,

Geoff

I think that you will find that this is usual and expected results if you are monitoring the processor and bandwidth. This forces the refresh time to be fast and constant. Which will require more bandwidth and processor ticks. I am posting a couple of screen shots to show you what I am talking about. Look at the drop in bandwidth as soon as I stopped monitoring, but still had connection. The unit I was connected to is Debian with (2) Ubuntu servers running in VBox.

Thanks Perryg.

Definitely, I would expect something like this if I were monitoring inside the VM, but I was monitoring on the host OS itself, and it doesn't seem right attaching a VRDP session would spike the CPU like it does. I attached a screenshot of what happens when I attach a vrdp session. This VM is just sitting idle and there is no desktop activity going on that would trigger an screen redraws.

I also did a wireshark sniff and the traffic is 30 MBit/sec, which sounds too believable to even type it. I attached a screenshot of it, and I am filtering for only the port where vrdp is registered (3390).

So it seems all this unnecessary traffic is driving the CPU spike. It seems that it isn't able to determine changed pixels, and instead is just doing a complete screendump.

thanks,

Geoff

Sorry but I don't have this happening here. I will look into this more tomorrow though and see if I can find out what might be causing your problem.
See next snapshot with the remote under my process explorer running.

I figured it out. I had the remote audio enabled in the rdp session. As soon as I disabled it, the traffic went down to a more reasonable figure.

thanks,

Geoff