110 nm Manufacturing Process, 8 W TDP
Looking at just the silicon, ATI is the clear winner over Nvidia this time. The Crossfire Xpress 3200 Northbridge - aka RD580, or 'Skeletor', as it is called internally at ATI - is produced by TSMC using a 110 nm process, making it the smallest core logic building block today. Its 22 million transistors require only 39 mm2. In addition to that, ATI states a Thermal Design Power (TDP) specification of only 8 W. As a result, the chipset does not require active cooling, nor a sophisticated (meaning expensive) heat pipe solution, as can be found on more and more enthusiast class motherboards with high-end chipsets.
Another benefit of the modern manufacturing process is that the RD580 overclocks pretty well without the need to increase voltage - and without creating high heat dissipation. We were able to run the Asus A8R32-MVP motherboard with a system base clock of up to 390 MHz, which represents an over 90% increase when compared to the 200 MHz stock speed. We could also achieve similar speeds with the A8N32-SLI, which uses the nForce4 SLI X16 chipset - although this achievement relies on sophisticated cooling.
As you will see in the power consumption section of the test results, the RD580 definitely offers an advantage over the Nvidia chipsets here, although the RD480 (aka Radeon Xpress 200) required less power.