Having the support of Asus has contributed much to the success of nForce4 SLI. Its A8N-SLI Deluxe was the first SLI board to arrive, but though early, it was an astonishingly polished design. It was also, right from the beginning, surprisingly affordable.
Asus hasn't been quite so evangelical about ATi's CrossFire chipset.Its first CrossFire board, the A8R-MVP, was a disappointment, but with the new A8R32-MVP, it looks as if Asus is taking CrossFire far more seriously. Firstly, there's the price tag; the A8R-MVP was one of the cheapest Socket 939 boards on test, the A8R32-MVP costs almost £150 and sports a 'Deluxe' tag. Secondly, the PCB is jet-black, rather than the grubby corporate yellow of the A8R-MVP.
It also uses ATi's new Radeon Xpress 3200 chipset, which provides two 16x PCI-E slots for dual graphics cards, just like Nvidia's nForce4 SLI X16 chipset. ATi uses a single chip to provide the 32 PCI-E lanes, whereas nForce4 SLI X16 uses two chips. ATi claims that its approach reduces latency, and increases bandwidth between the graphics cards. That said, in our tests we found that, like nForce4 SLI X16, there was no noticeable performance difference between two X1900-series cards in CrossFire on Radeon Xpress 3200 compared to Radeon Xpress 200.
Asus has also used a ULi M1595 Southbridge, which offers four S-ATA II ports. A fifth S-ATA II port is provided by a Silicon Image chip, although the port itself is marooned between the CPU socket and the motherboard's back panel. There are also two EIDE ports and a floppy port, plus three PCI slots and a 1x PCI-E slot. If you install two X1900-series cards in CrossFire, you lose access to one PCI slot and the 1x PCI-E slot. The on-board sound is 8-channel HD Audio via a Realtek ALC882 chip, a welcome improvement on the A8R-MVP's AC97 audio.
At stock speeds, the A8R32-MVP's performance wasn't exactly brilliant when compared with its Socket 939 peers. Its score of 1.03 in TMPGEnc DVD encoding was behind the 1.07 scored by the A8R-MVP, and it was similarly tardy in both the image editing and multitasking tests. The culprit was perhaps the M1595 Southbridge, which ran our S-ATA II Samsung test drive in 'Emulated PATA mode'. Attempting to switch to 'ACHI' mode caused all manner of problems, including corrupted Windows installations. Performance in Battlefield 2 was similar to the boards in last month's Labs test, supporting the theory that poor S-ATA performance scuppered the Media Benchmark scores.
ATi has talked up the overclocking prowess of the Radeon Xpress 3200 chipset, and in some ways, it's right. With our test CPU's multiplier reduced to its minimum, the A8R32-MVP benchmarked stably with a 350MHz FSB. This is much better than the 275MHz that the A8R-MVP managed, and the same as DFI's excellent CrossFire board. However, discerning overclockers will be disappointed by the level of voltage control that the A8R32-MVP offers. It has four-phase power circuitry, not the eight-phase seen on the A8N32-SLI Deluxe, and while it can send a useful 3.2V to the RAM, there's only an extra 200mV over the VID maximum available to the CPU. In the case of our 2.2GHz Athlon 64 X2 4200+ test CPU, this means just 1.55V. In practice, this meant the A8R32-MVP could only overclock our test CPU to a 235MHz FSB (2.59GHz) at its default multiplier before instability crept in. Even worse, it refused to run the RAM at a 1:1 ratio with the FSB. Hopefully, new BIOS revisions will sort out the memory issues, although the limited CPU voltage control probably won't change.
CONCLUSION
The A8R32-MVP is a big improvement on the A8R-MVP, but had it been in the Labs test at its current price, it wouldn't have changed our recommendations for people interested in buying CrossFire. It costs the same as the DFI Lanparty UT RDX200 CF-DR, which is a better overclocker. And if you're less interested in overclocking, then the MSI RD480 Neo 2-FI is much better value, despite having fewer features. The Radeon Xpress 3200 chipset clearly has potential, but sadly Asus hasn't managed to get the most from it.
Author: Alex Watson
Asus A8R32-MVP Deluxe