Changing desktop wallpaper affects performance

[sakh]

Hey guys,

Running VB 3.0.8 with Windows XP on 32 Ubuntu 9.10 in headless mode using rdesktop to connect.

When I set a large wallpaper, systems becomes barely usable whenever I move a window. CPU goes to 100%. If I choose no wallpaper, system works a lot faster. I have 128 mb of Video memory dedicated to the virtual machine and run desktop in 1680x1050 16bit mode.

Flash is also pretty slow in both.

[Sasquatch]

This is because (V)RDP uses bitmaps to display the Guest. A single colour takes less memory and space in a bitmap than a complex, multi-colour image. When you move a window, the whole image needs to be redrawn and that takes longer with complex images. Flash is the same problem, it's an animation that needs to be redrawn in bmp so you can see it.

[sakh]

So I assume the native VirtualBox client works differently and does not rely on these bitmaps?

What do you think would be a bottle neck for those bitmaps? Is it my my hosts graphics card, cpu, memory? Or the amount of resource I allocate for the virtual machine?

[Sasquatch]

Windows native RDP server has build in limitations to conserve bandwidth and reduce resources, the VRDP server from VB doesn't. Sometimes it's smoother than native RDP, but on slow network connections or hogged down systems (heavy load on CPU) it's actually slower. You could open a bug report about this in the Bugtracker (separate account needed).

[sakh]

So basically native VirtualBox application also uses a VRDP server, just a more suitable version of it? And when I connect to Windows using rdesktop my system talks to a standard Windows VRDP server that is not very good for my needs? Sorry about all the questions, I'm just trying to wrap my head around how these things work. So if set up a different VRDP server on Windows, it may provide better connectivity with rdesktop and the system won't have to deal with those bitmaps?

[Sasquatch]

Now you're confusing me. How are you connecting to what? Is it your Host, or the VM? If to the VM, is it to the OS directly, or to the VRDP feature of VBox? From your profile information I see you use the OSE edition, which doesn't have VRDP, so you must be connecting to the Guest directly.

[sakh]

I'm confusing myself to be honest

Anyway, my problem from the scratch.

Host: 32bit Ubuntu 9.10 with Gnome
Guest: Windows XP SP3 Pro
VB: VirtualBox 3.0.8 PUEL
Computer: Athlon 64 X2 4800+, 3GB RAM, 512Mb Nvidea 9400
Monitor: Asus VW222U 1680x1050

Objective: To be able to span virtual Windows over two workspaces.

Original idea that worked: Run Windows on VirtualBox in headless, set Windows desktop to "3360x1050x16", connect to windows RDP using rdesktop, rdesktops window takes dimension of Windows desktop, or 3360x1050 and spans itself over two Linux workspaces.

Problem: Because of what you explained about Windows RDP server and bitmaps, this solution is really slow when I move windows, or set wallpaper, or run flash. And flash applications are critical for me. I don't need openGl or Direct3D. I just need to be able to run flash.

When I use VirtualBox native client, everything works fast and great. But VirtualBox always resizes its window back to the size of the screen or 1680x1050 in my case.

Thats the basic problem and I'm kinda stuck. I need to either:

1) Find a way for VirtualBox window to hold desktop bigger than the size of the screen.
2) Find a bottleneck in "rdesktop + VB headless" solution and try to fix it
3) Find a different RDP server or Virtualizing software to do what I want.

I'm confused

[Sasquatch]

What you need is to read the manual. That describes how to enable and use multiple monitors.

[sakh]

I don't think you understand what I am saying. I don't have multiple monitors. I don't need multiple monitors. Even if I did or if I had, I would still have to run VB in headless, connect to RDP and have the same performance issues with bitmaps that I have now.

What I need is a VirtualBox client window that is 3360x1050 and that stays this way.

I attached a little picture explaining what I want more clearly.

[Sasquatch]

You're not getting the point. You don't need multiple monitors to use multiple monitors in the Guest. You said yourself, you want something that spans over two virtual desktops. That can be done with VRDP and multiple monitors in VB. Each desktop will run an rdesktop session.

[sakh]

I can do that without a problem, but how do I connect to VirtualBox VRDP server instead of Windows native RDP server?

[Sasquatch]

That's in the manual . Open the VM settings, click on Display and tick the checkbox next to "Enable Server" on the "Remote Display" tab.
Then you connect to your local machine using rdesktop as described in the manual, chapter 9.6.

[sakh]

I enable the server. I start the VB:

Code: Select all

VBoxHeadless --startvm "Windows XP"

Program says:

Code: Select all

VirtualBox Headless Interface 3.0.8
(C) 2008-2009 Sun Microsystems, Inc.
All rights reserved.

Listening on port 3391

Then I connect with rdesktop:

Code: Select all

rdesktop localhost:3391

And its slow. Nowhere as fast as VirtualBox GUI.

[Sasquatch]

Hmm, I've never experienced any slowness when I used VRDP.

[sakh]

Ye, I don't know whats going on. When I start VirtualBox GUI, set a large wallpaper and move windows around - I do get slowed down, but its ok. CPU use is around 30-40%. But when I connect with rdesktop, and do the same - CPU spikes instantly to 100%. Its only workable in 16bit mode without any wallaper or flash programs running. I think I have tried every rdesktop parameter and lots of different VB settings, nothing seems to work.