Board analysis

Looking over the two X1900 cards we received (a Radeon X1900 XTX 512MB and a Radeon X1900 CrossFire) our first thought was how surprised we were to see how closely they resembled the X1800 cards they’re replacing. Even an experienced Radeon X1800 card owner would barely be able to tell the difference between the Radeon X1900s and the X1800. ATI even uses the same shot of Ruby on the card’s heatsink/fan unit. Here we should actually note that ATI plans on using a black heatsink/fan unit with a different Ruby sticker for final, shipping Radeon X1900 CrossFire cards. The card ATI sent us for testing is a pre-release engineering sample X1900 CrossFire card. Final X1900 CrossFire boards should look like this:

Final design of Radeon X1900 CrossFire

ATI’s using the exact same board design and components for the X1900s (in fact, ATI uses the same board level components for the Radeon X1900 XT as they do the XTX, right down to the memory modules). We could only spot a couple of minute differences between our Radeon X1900 CrossFire and the Radeon X1800 CrossFire card we just reviewed a month ago; we couldn’t see any differences between the Radeon X1900 and the X1800. It literally looks like for the most part, ATI just dropped R580 onto R520’s PCB and went into full production.

This should help make the R520 to R580 transition that much easier for ATI and their board partners, as the exact same parts can be used for both cards. ASUS for instance shouldn’t have any trouble taking the same heat pipe-based Arctic Cooling VGA cooler used on the Extreme X1800 XT TOP and moving it over to the X1900 XT/XTX (Arctic Cooling has basically already confirmed this, so as long as ATI continues to sanction overclocking for R580, the chances of seeing a 700MHz Radeon X1900 card at some point in the future could be bright.

Also like the Radeon X1800, ATI runs the Radeon X1900 in two different modes. A 2D mode, which runs at slower clock speeds of 500MHz core/594MHz memory, and a 3D mode, which runs at the X1900’s full clock speeds.

Back of the X1900 XTX card

The CrossFire boards

The heatsink/fan unit on the X1900 operates identically to the cooler used on the X1800 since it’s the same cooling unit. The fan sucks in the air within your PC from the right side of the card, passing it across the VPU and its memory before it finally exits outside of your system’s case. ATI uses a combination of copper and aluminum to cool the graphics core and memory modules, while a bank of VRM circuitry is cooled with a second aluminum heatsink. If you stick your hand behind the card when it’s running, you’ll literally feel the hot air as is passes from the X1800’s back plate. It’s an effective system that works pretty well, but as we’ve noted in the past, it does run louder than NVIDIA’s GeForce 7800 GTX, particularly when two X1900 cards are combined for CrossFire mode.

The fan spins at varying RPMs that depend on the GPU’s current temperature. At full speed, the X1900’s fan can get pretty loud, but fortunately we only saw this speed when we were first booting up the system. Even when running with two cards in CrossFire mode, the fan on either card never ran at full speed.