There are some pre-tests about CrosfireX scaling in Anandtech. The 3 cores seems to be sweet spot at this moment, but maybe we will see more benefits from additional cores in the future. The best part is that even at this moment the CrosfireX seems to work ok with selected aplications. We will see some more supported aplications added before CrosfireX is officially released in the next month.
Game Resolution AA AF Detail Settings
Half Life 2: Episode Two 2560 x 1600 8X 16X Highest in-game
Unreal Tournament 3 2560 x 1600 0X 16X Highest in-game
Bioshock 2560 x 1600 0X 1X Highest in-game
Call of Duty 2560 x 1600 4X 16X Highest in-game
Crysis 1920 x 1200 0X 1X High Quality defaults
Number of GPUs HL2 UT3 Bioshock CoD4 Crysis
1 x Radeon HD 3870 39.3 46.7 36.9 25.3 14.0
2 x Radeon HD 3870 (1 X2) 71.9 84.1 63.2 50.0 26.2
3 x Radeon HD 3870 (2 X2 + 1) 93.3 112.7 86.7 72.2 26.4
4 x Radeon HD 3870 (2 X2) 102.2 114.6 92.5 93.2 27.7
Single to dual GPU scaling is similar with SLI as CrossFire, but the 2-way to 3-way gain is better on CrossFireX. NVIDIA's quad-SLI is not yet available so we're not sure how the 4-way scaling will compare, but so far it seems like CrossFireX is doing quite well in the pure numbers game.
Due to the state of AMD's driver optimizations DX10 games currently only scale well to 3 GPUs and not much beyond (Crysis/Bioshock), while DX9 games will generally scale better all the way up to 4 GPUs.
Drivers, drivers, drivers... Nice to see some improvement in Crysis minimun frame rates. But if the driver does not support multible GPU cores in particular game, you have got big room heater and nothing else!
I wanted to know if this crossfirex would improve scaling on 2 cards voer teh current method. AMD are very sketchy about this.
I think not, because CrosfireX is just ATI's way of doing xGPU driver. Of cource there will be some improvements in 1 GPU and 2 GPU, because ATI cards are so driver dependable, so any improvement in this area should improve the overall speed allso. IMHO
With multi-GPU configurations, avoiding CPU limitations is a very important issue at driver level - at the end of the day, enough CPU horsepower is still required to deliver frames to multiple GPUs in a timely fashion, an issue which becomes more important the more graphics cores (and thus the more frames required to be 'stacked up') you add. If the CPU can't keep up with providing those frames to the GPUs to work on, your multi-GPU scaling and performance begins to dip. ATI have worked hard to load balance everything as much as possible to avoid these CPU limitations, while also optimising the communications and calls between the graphics driver and CPU to be as efficient as possible.
Just to clarify, I want to pick up two HD3870X2's now, and I have an Intel Q6600. So I need a motherboard that supports the Intel processor and CrossFireX. I have no idea what to look for. Does the X38 chipset support CFX?
i am waiting for crossfirex benchmarks to go up ( thought there would be tons by now ) I have an x38 board with two 3870s now.. what I want to see is the scaling of my set up now compared with 1 3870x2, and one 3870 as well as against 2x 3870x2s. if the gain between 3 GPUs and 4 is not that much.. ill just get a 3870x2.. but if the 4th gpu adds enough of a boost.. ill sell both my 3870s and get 2 X2s
The test system was running Windows Vista Ultimate 64-bit with all available Microsoft updates including the hotfixes required for enthusiast video cards to run correctly. The CrossFireX testing was done with CATALYST 8.3 beta drivers and CATALYST 8.1 drivers were used on all the other Radeon HD graphics cards. NVIDIA Forceware 174.12 drivers were used on all GeForce graphics cards. All results shown in the charts are averages of at least three runs from each game or application used.
If the Beta is the same as the final release there is much good to be said for this release!!!
If you want our honest opinion, right now CrossFireX is sitting way out on the razor-sharp bleeding edge. When it works, the results can be very impressive. When it doesn't, the headaches, BSODs, uninstalling, reinstalling, and hacking that may be required is enough to make the best geeks cower in fear.