A closer look at the 2900 Pro
If you were to judge by appearance alone, you could say that the HD 2900 Pro is a HD 2900 XT in some makeup.
You can see the pictures for yourself: the only thing that differentiates the appearance of our ATI HD 2900 XT and this PowerColor HD 2900 Pro are the stickers and serial numbers. We have the exact same cooler; same capacitors; same PCB down to every etch.

Good thing there is a sticker on'em so we can tell them apart!
The HD 2900 Pro has 16 texture units, 16 render back-ends, and 320 stream Processors -- just like the HD 2900 XT.
You almost get the impression that each HD 2900 Pro was fated to be a HD 2900 XT, but somehow, something happened and it just turned out to be a HD 2900 Pro instead.

As for under the hood, the HD 2900 Pro has a core clock of 600 MHz, and the 512 MB of GDDR3 memory operates at 800 (1600 effictively.) You can compare this to the standard HD 2900 XT speeds of 750 / 1650. That's a fairly big gulf between the XT and the Pro, in respects to the core clock speed, but the HD 2900 Pro should be in the same performance bracket as a 8800 GTS. Pricewise, the PowerColor HD 2900 Pro retails somewhere around the $280 USD mark, positioning it well against the 8800 GTS 320 MB, which retails right around this price.

The PowerColor HD 2900 Pro also has the standard features found in the more expensive HD 2900 XT, including: CrossFire support, DX10 support, built-in HDMI, ATI Avivo high-def video playback, and 5.1 surround audio.