Depends a lot on your computer specs. Like is it a 64 bit os, how much ram do you have, what kind of graphics card and processor, and such.

Snow Leopard is completely 64-bit, unfortuantely I've got a shitty video card. It's an ATI Radeon x1600. Next to a C2D @ 2.33 and 4Gig of DDR2 RAM. It's my hawt for most stuff (including Maya), but those ginormahuge© poly counts are getting pretty serious.

I'll probably end up borrowing my roomie's () new gaming rig for Mudbox stuff.

Unless you know how to get distributed computing working between a Macs and Windows 7 boxes :)
...that would probably make me cream myself :D

It's most likely your video card. I googled and there's both a 256 and 512 mb version of that card so I don't know which one you have.Also check your status line in mudbox which is at the bottom right of the screen, specifically gpu mem. If that number becomes higher then your video card mb then your writing to disk and will get slow down.

One thing you can do is go under preferences and in the file drop down set enable preprocession on load to 1. It may increase performance. Also keep in mind, just because you can sculpt on 67 million (my maximum) doesn't mean you should. Take your map sizes into consideration. For example, if your using a 2k map texture the most theoretical polys you'll be able to capture would be a little over 4 million polys. Any details above 4 million wont be captured.

Yeah, I wouldn't be surprised if it's my card. I've got the 256MB version.

I start getting terribly sluggish around 4 or 5 subdivs. (5 is obviously worse). And I've been using 2k maps.

I'll definitely try those new settings. Thanks!! :D