INSIGHTS and OBSERVATIONS
a) 3D accelerated games run faster under Windows Vista than under Mac OS X. (See the Apple OEM cards tested under Mac OX Leopard.)
b) The Radeon HD 3870 X2 has two processors on a single card (a la 3Dfx Voodoo5). It would make an excellent Mac Pro upgrade if ATI/AMD would offer it in a Mac OS X compatible version -- compatible all versions of Mac Pro. Ditto for the GeForce 9800 GX2 from nVIDIA.
c) Notice how the dual Radeon HD 2600 XTs in CrossFire mode run twice as fast as the single Radeon HD 2600 XT. However, two are no match for the single GeForce 8800 GT.
As of April 15th, 2008, Apple started shipping the "legacy" version of the GeForce 8800 GT in a kit form for 2006/2007 Mac Pro owners. When you visit the Apple Store USA, click on "Displays" in the left column and look for the Geforce 8800 GT labeled "1st Generation." Let me remind you that our testing has shown this to be a strong 3D OpenGL gaming card but a weak Pro App card (Motion, Aperture, FCP). We believe a Mac OS X compatible Radeon HD 3870 would perform better for Pro Apps. We are urging ATI/AMD to release such a card and will alert you if and when that happens.
The GeForce 8800 GT functions fine under Windows XP or Vista but don't plan it jumpering two of them to run in SLI mode. It won't work on the Mac Pro. However, two ATI Radeon cards will run under Windows in Crossfire mode as you can see from the graphs.
FLASH! -- ATI Radeon HD 3870 for Mac will ship the end of May. We have received confirmation from a reliable source that a ATI will definitely offer a retail version of the ATI Radeon HD 3870 with 512MB DDR4 that will boot OS X on both current and legacy Mac Pros. It will, of course, boot Windows XP or Vista in your Boot Camp partition.
This is significant in that the Radeon 2600 XT beat the GeForce 8800 GT in Apple Pro App Core Image intensive testing. So the HD 3870 will do even better in Pro Apps but also be a strong gaming card. And, like the 2600, we expect it to support CrossFire mode under Windows if you have two installed and jumpered.