CrossFire With Radeon HD 4870 OC
The overclocked values are slightly better for two Radeon HD 4870 in CrossFire mode. At a resolution of 1920x1200 pixels with anti-aliasing, the MSI overclock results in an 18.6% performance increase in Crysis (where a single MSI HD 4870 OC card is 13%). If you consider all games in the benchmark suite together, the 3D performance over the standard card increases by 3.8% (a single MSI HD 4870 OC card is 3.5%).
Paired in CrossFire mode, the cards are no longer quiet. The noise level on the Windows desktop rises from 41.8 to 42.4 dB(A), but the higher fan speed drops the temperature to 63 degrees Celsius. In 3D mode, temperatures drop by 10 degrees compared to a single card. However, the noise level at 54.5 dB(A) is extremely loud, at roughly the same level as Nvidia’s GTX 260 or GTX 280.
The entire system in 2D mode consumes 242 watts, while in 3D mode this leaps to 460 watts. Anyone who wishes to use a HD 4870 in CrossFire will need a reliable power supply with somewhere between 380 and 420 watts and 32 to 35 A on the 12 volt rail.
In terms of performance, the HD 4870 CrossFire competes against the GeForce GTX 260 at 1680x1050 pixels with anti-aliasing. Backed by a more powerful CPU, we’d expect 3D performance to increase by a fair amount. The Core 2 used here means that the overall results—namely, a gain of 3.8% at double the price for two cards—is of less interest.
If you use the single card with the default clocking rate as the basis, the overclocked MSI models only show a 7% to 10% increase. If you look at the resolutions separately, the increase gained by CrossFire at 1920x1200 pixels with anti-aliasing is nearly 20%. At 1680x1050 pixels with AA, it is 18%. And at 1280x1024 pixels with AA, the gain is limited to around 6%.
These values are not unexpected. Only the new CPU classes are able to free up more performance with two cards. Older CrossFire combinations like the HD 3650, running current games and matched up with our CPU, are now able to achieve an increase in overall performance of over 60%. If you look at some of the games and resolutions carefully, CrossFire can be worth spending extra money on today. Mass Effect at 1920x1200 and 4xAA with the HD 4870 runs at 38.6 fps, but with the HD 4870 CrossFire it hits 74.0 fps. World in Conflict at 1920x1200 and 4xAA with the HD 4870 achieves 34.8 fps, yet with HD 4870 CrossFire reaches 44.6 fps.
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Looks like the results for SLI and Crossfire were switched with the single card results. . .Reply
Not a bad article, really comprehensive.Reply
My one complaint? Why use that CPU when you know that the test cards are going to max it out? Why not a quad core OC'ed to 4GHz? It'd give far more meaning to the SLI results. We don't want results that we can duplicate at home, we want results that show what these cards can do. Its a GPU card comparason, not a complain about not having a powerful enough CPU story.
Oh? And please get a native english speaker to give it the once over for spelling and grammar errors, although this one had far less then many articles posted lately.
No 4870x2 in CF so its the worlds top end Nvidia vs ATI mid to low end.Reply
It'd be a good article if you'd used a powerful enough CPU and up to date Radeon drivers (considering we're now up to 8.8 now), I mean are those even the 'hotfix' 8.6's or just the vanilla drivers?Reply
Version AMD Catalyst 8.6? Why not just say i'm using ATI drivers with little to no optimizations for the 4800's. This is why the CF benchmarks tanked.Reply
at 1280, all of the highend cards were CPU limited. at that resolution, you need a 3.2-3.4 c2d to feed a 3870... this article had so much potential, and yet... so much work, so much testing, fast for nothing, because most of the results are very cpu limited (except 1920@AA).Reply
WTF, hd4850 SHOULD be a lot faster than 9600 GT and 8800 GT even tough they have 1Gig of ramReply
No 4870X2 and 1920 X 1200 max resolution tested. How about finishing the good start of an article with the rest of it...Reply
I agree, the 4870 X2 should have been in there and should have used the updated drivers. Good article but I think you fell short on finishing it.Reply
@pulasky - Rage much? It's called driver issues you dumbass. Some games are more optimised for multicard setups than others, and even then some favour SLi to Crossfire. And if you actually READ the article rather than let your shrinken libido get the better of you, you'll find that Crossfire does indeed work in CoD4.Reply
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