This board is called the P5RD2-MVP Deluxe, and it combines the ATI Radeon Xpress 200 CrossFire north bridge with the ULi VT1573 south bridge. Asus says the demo system is running a Pentium 4 670 3.8GHz, Kingston DDR2 DIMMs at 750MHz, and a pair of Radeon X850XT cards. Note that all cooling on the board itself is passive. That should keep onboard noise limited to two screaming video cards and the massive CPU cooler, thank goodness. Asus told us this would be the only live demo of a CrossFire board that we would see at Computex, and they were rightfor about 30 minutes.
Then we visited DFI, who is working on a LANParty version of ATI's Radeon Xpress 200 CrossFire chipset for the Athlon 64. They have this Socket 939 board hanging on the wall in their booth, like so:
This is a six-layer, Socket 939 board that boasts an ATI south bridge with High Definition Audio support, a Promise SATA controller with four ports of 300MB/s SATA, PCI-E switch chips to redirect PCI Express lanes to one or two video slots (one x16 or two x8) without jumpers, and DFI's nifty mag-lev fan to keep noise levels low.
We were whisked away upstairs in DFI's booth, away from the show floor, where this mobo was running in a live demo with a pair of graphics cards.
Curiously, the first thing DFI showed us was what they described as a pair of slave cards running together cooperatively. The DVI output to the LCD display was only hooked to one of the two video cards, and the system was running 3DMark05. I asked how the cards were sharing data, and the gent pointed to the north bridge chip between the two cards. When 3DMark finished, the score came out like so:
So, uh, I suppose a CrossFire master card with an image compositing engine isn't strictly necessary for multi-card acceleration. He said that you could hook up the monitor to the DVI output on the secondary slave card and see only half of the frames when the cards are rendering in alternate-frame mode, but I utterly failed to force him to show me out of foolish politeness. He also told me that the two cards must be an exact match in order to run in dual slave mode.
The dude from DFI then swapped in a true CrossFire master card from ATI alongside one of the the X850 XT PE cards and proceeded to flash the slave card to what he said was a Radeon X800 BIOS, so it would match the CrossFire card. Both had dual-slot coolers that looked for all the world like X850 XT cards, but whatever. He then ran 3DMark for us again, this time with the video cables daisy chained as one would expect for a CrossFire config:
This master-slave configuration with slower cards produced a slightly lower score than the dual-slave X850 XTs, but it was still crazy fast. I noted, as 3DMark's Game 3 test ran, that there was some slight frame-to-frame jumpiness that seemed rather out of place, since everything else looked so very smooth and fast. Apparently, this setup still isn't working 100% as it should, but the performance promise is obvious.