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.
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yacoub - Friday, July 22, 2005 - link
#17 - what native resolution "thing"? I quite often play at lower resolutions than my monitor's 1280x1024 and it windows it quite nicely on my over-two-year-old LCD (meaning the technology has been around for a while now to make it look good). It shows it at the actual resolution with black around it like a letterboxed movie on a TV screen. Or I simply play it in Windowed mode if the game supports that (most do) and that way I can keep an eye on my instant messenger messages while playing the game. :)yacoub - Friday, July 22, 2005 - link
I'm glad to see Splinter Cell: Chaos Theory in the benchmarks because that game alone could justify someone's purchase of SLI/Crossfire cards. As can be seen in all the SC:CT benchmarks at Anandtech, it's quite the GPU-taxing game. Only with Crossfire or SLI'd 7800GTXs, are you looking at smooth gameplay of 60+fps in 1600x1200 4xAA (although since Anandtech doesn't post "Min" "Max" and "Average" fps numbers along with a graph of the fps throughout the testdemo, it's hard to know for sure that it never dips into slower territory.rjm55 - Friday, July 22, 2005 - link
#15,16,17 - I just retired a 22" Diamondtron CRT earlier this summer. The REAL screen size was 20" and it did 2560x1600. This summer from hell made me realize how hot CRT's get. My computer room is at least 8 degrees cooler now.CRT's do fine in gaming, but they are declining. Most new sales are LCD. They may have to pry your CRT from your dead hands but LCDS are what people - and gamers - are buying. You don't have to like it, but it is still a fact.
Frallan - Friday, July 22, 2005 - link
#8[quote]SLI is a waste of money when you can buy a 7800GTX for $550 at newegg. The increase in power requirements, setup headaches, AA headaches is simply not worth it when you get basically the same kind of performance from a single card.[/quote]
Nope Ure wrong re: price I got my 6800gt when it was new Ill soon be buyin a second 6800gt and I will have played the whole time and still sopent less.
[quote]Finally, it's stupid to buy this setup just so you can run at 2048/1536 with 4X AA. No one with that kind of cash, runs on an old crt. Everyone with that kind of money has an LCD that's either 1280/1024 or 1600/1200 and for those, a single setup based on the 7800GTX is the cheaper and more reliable solution...unless you're an ATI fanboy. If so, then go waste your cash. [/quote]
BS - I have that kind of money and Im using my old CRT (EIZO F58) to goto 16*12@85Hz. So far have not seen 1 LCD that stood up to my standards re. color, responstime and resolution. So sorry Ure just plain wrong.
Kegh - Friday, July 22, 2005 - link
I will be replacing my current PC this winter with a new one. I do not see enough bang for your buck to go with xfire, especially since a single 7800gtx and presumability a single R520 will run within 5% of the xfire setup. Plus dealing with two cards = twice the heat / fan noise. Also xfire using 800 series gpu's is no bonus.I think this setup only makes sense if you currently own an 800/850 card. It "may" cost less to upgrade then. Wasn't the xfire 850 card going to retail for $550 (minus the $100 rebate which ati has going on) = $450... Plus $100+ for a new mainboard and we are back at $550... or you can buy a single 7800gtx for same amount and have an easy upgrade... Which would someone rather do?
Most likely I'll go with a single R520. They should be out by xmas! :)
zmanww - Friday, July 22, 2005 - link
#11"the performance increase from a single X850 XT to CrossFire is up 43% as opposed to SLI's benefit of 34% over a single card"
I just can't wait till R520 comes out, then ATI and nVidia will have a real showdown.
dmfcomputing - Friday, July 22, 2005 - link
i always laugh at "gamers" with LCDs... the whole native resolution thing makes real gaming a pain in the ass. my 19" high end viewsonic CRT can do 2048 (but i only have a 6800gt, so not many games i can push up that high). I play almost all games at 1600, but if i got battlefield 2 (im not interested in EA crap like that tho) id have to switch to 1280, which would screw up your LCD. besides it costs a hell of a lot of money to get a 1600 LCD, much less a high res one. and honestly, the picture just doesnt look as deep as a good aperture grill CRT. and unless your paying tons of money for some 8ms LCD, youll get ghosting at good FPS levels. i will never buy an LCD as long as theres a good CRT out there. They just suck for gaming.Turin39789 - Friday, July 22, 2005 - link
Agreed #15 - LCD's are nice, and getting nicer. But for gaming I don't feel you can beat a quality 21' crt. And with the way prices are falling ( I just got an off lease 21' for $100 + 50 shipping) you'll have even more money to drop on a nicer video card, or even a second monitor.MrSmurf - Friday, July 22, 2005 - link
#13, most hardcore gamers who Crossfire is marketed to play on CRTs and should be able to hit resolution higher than 1600x1200.Warder45 - Friday, July 22, 2005 - link
Nothing really that supriseing. Games where the X850XT beat the 6800 Ultra are the same games where X850XT crossfire beats the 6800 Ultra SLI, and vise versa. The 7800GTX is of course well as it's a next gen part; once the R520 comes out I'd assume to see some competition. I have to agree with those above, ATI really should have switched priorities and launched the R520 now and launched crossfire in aug/sept.