virtualbox.org

Hello! My machine is medium level - CPU AMD Sempron 2200+, overclocked from 1500 to 1800 MHz, Video adapter Nvidia GeForce 6600 with driver 191.07, and 2 Gb RAM. Host OS is Win Vista Business. I'm using VirtualBox 3.0.8, with guest OS Win XP Professional SP2. Additions are installed. Guest runs smooth and easy, except of video playback. When playing video on any player, CPU load is 100 even with small window size. Host RAM allocated is 512 MB, host video RAM allocated is 12 MB, increasing video RAM won't help. Can anyone tell me what settings can I try in order to increase video performance? Thank You!

The video overlay in the VM is being done without hardware assistance, hence the high CPU overhead. You could try enabling 3D acceleration, and see if that helps. You need to have installed 3D acceleration support with the guest additions for this to work (I suggest you backup the VDI file or create a snapshot before trying this, in case you want to undo this step).

I don't know that enabling 3D acceleration enables hardware overlay as well: let us know if it helps or not.

Well, that's what I did:
-checked 3D support in VM settings
-booted in safe mode
-uninstalled guest additions
-rebooted in safe mode
-reinstalled guest additions with 3D support option checked in installer
-rebooted normally

After this video plays a little bit faster (or it's just seems to me), but still jerky, and with 100% CPU load.
I use Media Player Classic for playback.

And, I opened task manager and noticed, that player process "mplayerc.exe" consumes only 50-80% of CPU even in allmost full-screen size. Other resources are consumed mainly by process called "System" (15-25%). And, when I pause player, CPU load from both "mplayerc.exe" and "System" drops to near zero simultaneously. To be clear, I'm talking about "System", not "System Idle" process. Any ideas what's going wrong?

vovanius wrote:player process "mplayerc.exe" consumes only 50-80% of CPU even in allmost full-screen size. Other resources are consumed mainly by process called "System" (15-25%). And, when I pause player, CPU load from both "mplayerc.exe" and "System" drops to near zero simultaneously. To be clear, I'm talking about "System", not "System Idle" process. Any ideas what's going wrong?

That's normal. Without hardware assistance the video overlay is being done by graphics routines inside the operating system, hence the OS and mplayer between them would be using CPU.

From the results of your experiment it looks like 3D acceleration does not yet include a hardware assisted video overlay, which I find a bit surprising. I'm afraid that performance will always be poor until that changes.

What type of videos were they anyway? What codec?

Video was .avi (xvid * mp3) and .mpg (mpeg1). About 400x300. Media Player Classic 6.4.9.0. Video & audio decoders - ffdshow revision 2527 (latest official from Dec 17 2008). Same player with same decoder & same settings shows very good performance on host Vista. Of course, the only difference is I set output to overlay mixer on guest XP, and on host Vista it's set to VMR9.

vovanius wrote:Media Player Classic

MPC is known for that(insufficient buffering), try vlc player.