I'm running Sabayon 5.1 (Gnome, x86) as a guest in the latest version of VMWare Fusion on my 13-inch MacBook Pro (5,5) with Snow Leopard. It's performance is absurdly slow, even when using a light window manager such as Openbox, and I can't figure out why.

VMWare settings for Sabayon VM:
-2 processor cores (it's even slower when set to use 1 processor core)
-880 MB RAM
-3D enabled

MacBook Pro hardware specs:
-Processor: 2.53 GHz Intel Core 2 Duo
-Memory: 4 GB 1067 MHz DDR3

Any advice? Maybe I'm missing a driver or something? I can provide more detailed specs if necessary. Thanks.

Try setting the IO scheduler to noop by adding elevator=noop when booting into Sabayon. Also try to setup a ramdisk in MAC OS X and use that for VMware logging and other temporarily files that VMware creates. Putting the virtual machine in full screen should provide you more performance.

Try to turn off Quartz Extreme in Mac OS X because it uses the video card to handle some processing.