Final Words
It has taken a very long time for the first retail ATI Crossfire motherboard to arrive. However, ATI could not have done better than to have the first retail board come from DFI, the current leader in motherboards based on the nForce4 chipset. In every performance area important to overclockers and AMD hobbyists, the DFI is at least as good as the legendary DFI nForce4 motherboards. In some areas, the DFI RDX200 is even superior to their nForce4 boards.
DFI took many of the excellent overclocking features of the landmark ATI Crossfire Reference board and added their own unique mark in the final mix. This is the first time that we have seen 4 double-sided DIMMs able to operate at 1T, and it also works using either 1GB or 512mb DIMMs. We don't know how DFI achieved this impossible task, but we can tell you that it works, and the performance boost is very real. The DFI also has a working CAS 1.5 option in the RDX200 BIOS, which is also a first on the AMD Athlon 64 platform.
Buyers are still amazed at the incredible array of tweaking adjustments and voltages on the DFI nForce4 motherboards, and we can only say that the ATI chipset version is even better. Voltages still go to 4.0V to support any memory that you can buy in any overclock situation, but this ATI version has even finer granularity and there is no need for a jumper to draw off the 5V line. Memory control options are even better than the nForce4 version, with DRAM drive strength options from 1 to 15 (1 to 8 to support 2 DIMMs and 9 to 15 for 4-DIMM control).
Some of the new performance options required some compromises on the board. For instance, the highest clock that we could achieve was 305 instead of the 318 that we saw on DFI nForce4, but that is an acceptable tradeoff for the incredible 4DSx1T performance option. All-in-all, the DFI LANParty UT RDX200 has the aura of being a more refined overclocker's board than the outstanding DFI nForce4 boards. Part of the reason for this is ATI's own excellent Reference design, which had already refined many of the most desirable features from an enthusiast and overclocking point of view. The overclocking features work, very smoothly, and without surprises, which can only be a good thing if you are an enthusiast.
While we have no complaints in the performance area or in the overclocking options and controls, we do have some complaints in the features area. It is a total mystery why DFI chose to add the Silicon Image 3114 SATA1 controller to a chipset that lacks native SATA2 support. With a SATA2 controller, buyers would only have to forgive less-than stellar USB performance on a board that is absolute tops in every other area. With the 3114 choice, there will be too much to forgive for some users. Certainly, neither SATA2 nor the zippiest USB are critical to most enthusiasts and those buyers will find everything that they want in the DFI RDX200. However, if these features are very important to you, you will have to add controllers or look elsewhere.
Last, there is the choice of southbridge. The SB450 is out of date as it launches, missing both SATA2 and NCQ support, and showing USB 2.0 performance that is not really competitive. Otherwise, it is plenty fast and capable, but you shouldn't have to make excuses with a chipset as otherwise capable as the Rx480. The good news is that SB600 will fix these somewhat minor failings and is a pin-compatible drop-in for SB450. The better news is that the ULi M1575 southbridge fixes those issues today and is an available option for ATI chipset motherboards. The DFI RDX200 would have been close to ideal with the M1575 features and performance.
In looking at the larger picture, ATI has to be extremely pleased that a high quality ATI RD480 motherboard is finally on the market. This DFI RDX200 is a superb board for the overclocker, whether they will use air, water, or phase-change cooling. This board, like the ATI Crossfire Reference board, was designed to be pushed to the limits. This means that the talk and speculation is over, and NVIDIA does have a worthy AMD chipset competitor in ATI. In fact, ATI is showing that it can cater to the AMD enthusiast with options and performance that will set the tone for future AMD chipsets.
(4x512 cas1.5 2-2-2 )
