Just as we had expected, the GeForce GTS 250 SLI configuration showed a very impressive performance in modern 3D games. It was considerably faster even than the GeForce GTX 285 across a number of applications thanks to its advantage in core clock rates as well as in the amount of ALUs (256 against 240) and texture processors (128 against 80). We are going to present the summary data to you now.
At a resolution of 1280x1024 pixels the average performance growth from switching from one GeForce GTS 250 to two such cards amounts to 64%. It varies from 18% to almost 100% depending on the specific application. In one new game (Tom Clancy's H.A.W.X.) there was a performance hit because the current version of the GeForce driver does not yet support SLI mode for this application.
The GeForce GTS 250 SLI configuration is also good in comparison with the GeForce GTX 285, enjoying an average 10.5% advantage over the latter. The single exception is Tom Clancy’s H.A.W.X. which again reminded us of the fundamental vulnerability of all modern homogenous multi-GPU solutions. We mean their dependence on software support.
It is not so easy to name the better one between the GeForce GTS 250 SLI and Radeon HD 4850 X2. If you calculate the average result, the former solution has a 5% advantage over the latter. However, Nvidia’s SLI configuration wins only seven out of the 15 tests whereas ATI’s solution wins the other eight. And we mean not only the extremely rare Radeon HD 4850 X2 which has only been released by Sapphire but also any Radeon HD 4850 CrossFireX tandem. Considering the recent price cut, the latter configuration is going to be a dangerous opponent to the GeForce GTS 250 SLI. Besides, CrossFireX-compatible mainboards are more widespread on the market than SLI-compatible ones.
When we switch to the resolution of 1680x1050, the efficiency of Nvidia SLI technology with respect to GeForce GTS 250 grows up to 69%, but the average advantage of the corresponding tandem over the GeForce GTX 285 drops to 9%. Besides Tom Clancy’s H.A.W.X., the SLI configuration is now slower than Nvidia’s flagship in Enemy Territory: Quake Wars, although by 3% only. The competition with the Radeon HD 4850 X2 gets tougher: the average advantage of Nvidia’s tandem shrinks to 1.5% but it wins nine tests now.
The display resolution grows up and so does the efficiency of the SLI configuration built out of two GeForce GTS 250 cards. The efficiency is 75% on average, but rises to 100% and more in three out of the 15 tests. The tested multi-GPU configuration outperforms the GeForce GTX 285 in most of the tests at this resolution, too. The exceptions are Tom Clancy’s H.A.W.X. and World in Conflict. The GeForce GTS 250 SLI equals ATI’s multi-GPU solution that has a similar price and capabilities in speed but wins eight tests and loses seven.
In the highest display resolution the GeForce GTS 250 SLI tandem is slower than the GeForce GTX 285 in four out of the 15 tests, namely Enemy Territory: Quake Wars, F.E.A.R. 2: Project Origin, World in Conflict, and Tom Clancy's H.A.W.X. The dual-processor configuration is on the winning side overall. We should note, however, that the single-chip card ensures more comfort in some games, e.g. in Far Cry 2, because it offers a higher bottom speed. The dual-chip solution from Nvidia loses in its competition with the ATI Radeon HD 4850 X2 but not by much: the ATI solution wins eight and loses seven tests. Moreover, the GeForce GTS 250 SLI can occasionally ensure comfortable conditions for the gamer where the opponent fails, for example in Fallout 3.
Summing everything up, the idea of uniting two GeForce GTS 250 1GB cards, each costing $149, into a SLI tandem is viable because such a configuration is generally superior to the GeForce GTX 285 in performance. The latter is also more expensive as yet. Its retail price starts from $340-350. On the other hand, it does not require a SLI-compatible mainboard as the GeForce GTS 250 SLI tandem does. And the choice will be limited to mainboards with nForce chipsets for both Intel LGA775 and AMD AM2/AM2+ platforms.
The performance benefits provided by the GeForce GTS 250 SLI tandem are generally not crucial and do not open new opportunities for the gamer that are unavailable with the single GeForce GTX 285. Therefore we consider the latter as a better product that does not depend on multi-GPU support in the driver. Building the SLI tandem will only make sense if you cannot spend more than $150 for your graphics card today, but you are going to increase your graphics subsystem performance in the near future. But don’t forget that you will also need an appropriate mainboard.