AnandTech Exclusive: CrossFire Benchmarks Revealed
by Derek Wilson on July 22, 2005 6:00 AM EST- Posted in
- GPUs
The System
The GA-K8AMVP Pro is based on the ATI's latest RD480 chipset paired with a ULi south bridge and features CrossFire support. We'll be taking a closer look at this board as well, as Gigabyte tells us that it can even support 2x 3D1 cards. The board looks very similar to Gigabyte's NF4 SLI boards, including the selector paddle for configuring the PCI Express ports. Flipped to single GPU, the first PCI Express slot gets 16 lanes, and flipped to multi GPU mode will run each slot at x8.
The board itself is stable and runs well. We had no problems with the platform while running our tests, and performance seems to be very solid. On this board, the master card had to be plugged into the slot closest to the CPU.
Our CrossFire master card looked very similar to a regular X850 XT. The port furthest from the motherboard connects to the dongle, which plugs into the monitor as well as the port closest to the motherboard on the slave card.
The card really does look a lot like a normal X850 XT, but we can see that the solder points for the Rage Theater chip are missing and there are quite a few components on the board in its place. All this circuitry (along with a couple of surface-mount LEDs) is likely part of the hardware needed to combine the output of both cards for final display. NVIDIA's parts don't need quite as many additional board components, as the GPU has die space committed to multi-chip rendering and all the work is done on the GPU and in the frame buffers.
That's not to say that ATI's solution is less adequate. Since the DVI port is inherently digital, the external dongle does nothing to lower image quality like the old analog dongle that 3dfx used to employ for SLI.
Before we get to the benchmarks, we will note again that with the early hardware and drivers, we had some trouble with some of the games and settings that we wanted to run. We tested most of the games that we ran in our recent 7800 launch article, but we ended up seeing numbers that didn't make sense. We don't have any reason to think that these problems will remain when the product launches, but it does shorten the list of games that we felt gave a good indication of CrossFire's performance.
For our tests, we used numbers from our original 7800 GTX review. The system (except for the motherboard) is the same as the setup used in the 7800 review (FX-55, 1GB 2:2:2 DDR400, 600W PSU, 120GB HD).
And what are our results? Take a look.
Facebook
Twitter
RSS
65 Comments
View All Comments
CP5670 - Friday, July 22, 2005 - link
It depends on the person. I can notice a considerable amount of ghosting in a fast paced game like UT2004 even on an 8ms LCD.I would never go with an LCD for any kind of gaming for a number of reasons, but anyway I got a top notch CRT a month ago and don't need to worry about LCD limitations for a couple of years at least.
Guspaz - Friday, July 22, 2005 - link
I'm a laptop gamer. I've got an older Mobility Radeon 9700 Pro, so I can't run everything at the native screen size of 1400x1050. As such there are many games that I play at 1024x768, or even 800x600 in the more extreme cases.Games look just fine with modern LCD scaling. That is to say, a 1024x768 game looks very good scaled up to 1400x1050. When ATI was designing their scaling algo, they obviously focused on making the pixels look square, rather than just doing a simple bilinear transform.
The point of scaling on LCDs may be moot to serious gamers though, as modern desktop cards often don't need to run games at below native res. And when they do, I can report they still look good scaled up.
I can also report that the response rate ("motion blur") is totally overblown. I've got a laptop, which obviously means I've got a pretty high response time (Probably 25ms to 30ms). Motion blur is noticeable, but isn't really distracting except in very bright areas. Desktop LCDs have improved a great deal beyond this with significantly lower response times to the point where it isn't an issue at all. I understand contrast ratios have also improved. All that is really left is colour saturation/accuracy (as a thing that CRTs are better at).
Most gamers I know with modern PCs have LCDs now. CRTs are dying, slowly but surely, much like DVDs slowly replaced VHS. LCDs already outsell CRTs, and adoption among gamers is possibly even higher than the regular computer buying public.
jkostans - Friday, July 22, 2005 - link
#23 no serious gamer would play in a window, and how can you not see the drawback of shrinking the screen size to get a lower resolution? Why turn a 19" display into a 14" display? I'm sorry but my 21" crt can do any resolution and still use all of the screen space and not interpolate. LCDs can't period and that's a big deal for 99% of gamers. Oh and #21, CRTs will be around until there is a technology that is fit to take its place. LCD panels are not even close to the quality of a good CRT display.blwest - Friday, July 22, 2005 - link
Can we do this benchmark on a NON ATI chipset?Samadhi - Friday, July 22, 2005 - link
This article shows the need for a lot more reviews of high resolution LCD devices from a gaming perspective.fungmak - Friday, July 22, 2005 - link
Anand or Derek - two quick questionsWhats the configuration of the slave and master card. Is it an XT as master and XT PE as the slave?
Obviously the speedup for crossfire would be a little bit more if you just used regular XTs instead of XT PEs for the single, if it was just two crossfired XTs.
Finally, in the Far Cry benchmarks, the single ATi card is labelled as the XT, but in the others, the single ATi card is an XT PE. Is this a typo?
Sea Shadow - Friday, July 22, 2005 - link
Seems like they were CPU limiting most of the benches, only 1600x1200 isnt demanding that much from the 6800 Ultras, x850s, and 7800s in SLI.BuddyHolly - Friday, July 22, 2005 - link
This is not quite a paper launch, but more like a paper review. Almost useless in helping me decide what my next video purchase will be other than to show that Crossfire does in fact work.How about the important stuff? When will it ship? How much? And where is the next generation ATI card and when will it ship?
I want more competition so I can retire my 9800pro and get a PCIe card, motherboard and processor without having to morgage my house or go without eating for a month...
Shodan2k - Friday, July 22, 2005 - link
To Derek WilsonWhich ATi driver did you use for the CrossFire setup?
yacoub - Friday, July 22, 2005 - link
So the point of this is that Crossfire with two last-gen GPUs (XT850s) doesn't perform quite as highly as SLI with two current-gen GPUs (7800s)? That makes sense. If/when the next-gen (current-gen) ATI cards are released I would expect them to do as well or better when Crossfire'd compared to SLI'd 7800GTXs. We shall see. :)