DFI LANParty UT RDX200: ATI’s Crossfire AMD for the Bleeding Edge

Performance of Features

When you receive a board Friday afternoon that will go on sale Tuesday morning, there is sometimes just not enough time to complete all the tests that you initially planned. In the interest of bringing you the most significant test results on the DFI RDX200, we concentrated on two areas of interest, specifically USB Performance and CPU utilization of the Karajan audio module.

For additional information on the performance of other Storage, Ethernet, and Firewire, please go to other recent ATI Rx480/482 reviews at "ATI's Crossfire: Best Overclocker on the Market?" and "Sapphire PURE Innovation - ATI's Chipset for the AMD Enthusiast". The performance of the feature accessory chips present on the DFI RDX200 are tested in those reviews.

USB Performance

USB has been a problem area for the ATI SB450 chipset, so we decided to see if anything had changed. We ran our standard USB throughput test on the DFI using an external USB hard drive.

Our test method uses a RAM disk as our "server", since memory removed almost all overhead from the serving end. We also managed to turn off disk caching on the USB and Firewire side by setting up the drives for "quick disconnect" and our results were then consistent over many test runs.

We use just 1GB of fast 2-2-2 system memory set up as a 450MB RAM disk and 550MB of system memory. Our stock file is the SPECviewPerf install file, which is 432,533,504 bytes (412.4961MB). After copying this file to our RAM disk, we measured the time for writing from the RAM disk to our external USB 2.0 or Firewire 400 or Firewire 800 drive using a Windows timing program written for AnandTech by our own Jason Clark. The copy times in seconds were then converted into Megabits per second (Mb) to provide a convenient means of comparing throughput. Higher Rates, therefore, mean better performance.

Nothing has really changed with USB performance since we looked at the issue in tests of the Sapphire Grouper and ATI Crossfire Reference boards. Sustained USB performance remains at about half the expected performance level. ATI tells us that this will be fixed with SB600 early next year.

There is an alternative in the ULi M1575 southbridge, which we recently tested. The ULi SB provides competitive USB performance and the SATA2 ports, which are missing from the ATI SB450 - and it is available today. We asked DFI why they chose the SB450 instead and they responded that the design work for the RDX200 was far along when the M1575 became an alternative. DFI also pointed out that M1575 and SB450 are not pin-compatible, thus making a last minute change in southbridge to be a very costly option. The SB600 should be pin-compatible with SB450, as M1575 is pin-compatible with M1573. When the SB600 is available, DFI will use the SB600 instead. They may also consider an SB change in their upcoming ATI dual x16 motherboard.

Audio Performance

For audio testing, we used Rightmark 3D Sound CPU utilization test, which is the same benchmark run in our earlier nForce4 SLI and Ultra roundups. This benchmark measures the overhead or CPU utilization required by a codec or hardware audio chip. We tested performance both with the earlier version 1.24 that we had used for past testing and the latest version 2.1. As you will see, 2.1 does yield different performance numbers.

None of the onboard audio solutions were quite as low in CPU utilization as the hardware Creative SoundBlaster Live! chip, which is used on the MSI K8N Neo4 Platinum. However, ATI's High Definition Audio on the DFI Karajan audio module turned in excellent performance in all the utilization tests. Results for Karajan HD Audio module were, in every case, almost as good as the hardware solution. Abit's separate Audio Max board and the nForce4 DFI Karajan Sound Module appear to lower CPU utilization of the ALC850 codec substantially. Azalia HD is apparently even more demanding of CPU power, but CPU utilization remained below 6.5% even in 3D audio rendering as tested with RightMark 2.1. The earlier version 1.24 still shows CPU utilization at 8.4% and below.

It is very important to point out that the DFI LANParty UT RDX200 is the first Athlon 64 retail motherboard to deliver Azalia High Definition audio. Those who have been complaining about the poor AC'97 audio present on most AMD boards should be very pleased to find Azalia HD on the ATI chipset boards.

DFI claims that the Karajan module lowers noise using an on-board audio solution. We did some subjective listening tests with the DFI's version of Azalia HD through a Dolby amplifier and a 5.1 speaker setup. We really couldn't hear a huge improvement over our last listening tests of ATI Azalia HD. Perhaps that was because our last experience with Azalia HD on AMD was so good. HD really is in a completely different league from the other audio solutions that we have tested on Athlon 64. Noise was virtually non-existent, and imaging and depth were superb when listening to demanding CDs. The same CD sounded thin, noisy, and artificial through a more common ALC850 fed to the same Dolby amp and 5.1 speakers. This is not to say that the Azalia HD is at the same level as the very best audio cards, but it is a lot closer than you might think.