Although their performance is largely equivalent, the CrossFire Xpress 3200 AM2 and nForce 590 SLI really couldn't be more different. ATI's chipset is a rather simple affair, with a solid spec but few frills or extras, while NVIDIA's latest nForce is jam-packed with peripherals and additional features, some of which are more gimmicky than others. Fortunately, both are easy to recommend, but for different reasons.
The CrossFire Xpress 3200 for AM2 is the first all-ATI chipset we have no qualms about recommending. ATI's new SB600 south bridge appears to have resolved the I/O performance issues that afflicted the SB450. With a solid Native Command Queuing implementation, support for 300 MB/s transfer rates, and RAID 10, the chip's feature set doesn't leave us wanting. However, the SB600's lack of integrated Gigabit Ethernet does leave the door open for motherboard manufacturers to use cheaper GigE chips with less appealing performance characteristics, specifically higher CPU utilization. Some will get it right, but as we've seen with Xpress 3200 platforms for Socket 939, others will almost certainly get it wrong.
Fortunately, motherboard makers shouldn't be able to mess with the Xpress 3200 AM2's exceptionally low power consumption and conservative cooling requirements. Those characteristics make this chipset ideal for low-noise applications, although you probably don't need a dual x16 CrossFire board in a home theater PC.
While ATI has created a relatively lean high-performance chipset with the CrossFire Xpress 3200 AM2, NVIDIA has gone in the other direction with the nForce 590 SLI. This latest nForce packs loads of connectivity options, including an impressive six Serial ATA RAID ports and two Gigabit Ethernet controllers. Extra features are what really make the nForce 590 SLI stand out, though. Things like FirstPacket and hard drive performance profiles are particularly intriguing. LinkBoost comes across as little more than a gimmick, though, especially since its compatibility is currently limited to GeForce 7900 GTX graphics cards. NVIDIA's much-improved nTune system utility has more potential, but as with earlier versions of the software, it's up to motherboard manufacturers to take advantage of the app's capabilities. Few mobo makers have fully exploited nTune's capabilities in the past, leaving us doubtful that many will fully support the app this time around.
Features aside, the nForce 590 SLI's peripheral and gaming performance are generally excellent. The chipset's disk controller, Gigabit Ethernet, and USB components are particularly impressive, although our nForce 590 SLI test rig stumbled in a number of WorldBench application tests. We're also not enthusiastic about the nForce 590 SLI's higher power consumption and cooling requirements.
Ultimately, motherboard manufacturers must properly implement the latest AM2 core logic offerings from ATI and NVIDIA. Those using the CrossFire Xpress 3200 will have to be careful to include the right auxiliary Gigabit Ethernet chips, and they will probably want to throw in an additional Serial ATA controller with RAID 5 support. Others implementing the nForce 590 SLI will have to pay special attention to chipset cooling and would do well to include all the BIOS hooks necessary to support NVIDIA's nTune system utility. Which chipset is right for you depends largely on whether you prefer extra peripheral connectivity or lower power consumption and heat output. I suppose if we view these chipsets as individual components, the nForce 590's more extensive array of integrated features and peripherals make it a more impressive product. However, with the right mix of auxiliary peripherals, motherboards based on the Radeon Xpress 3200 will be very competitive.