NVIDIA GeForce GTX 260M vs NVIDIA GeForce GTX 285M SLI

NVIDIA GeForce GTX 260M

The NVidia GeForce GTX 260M is a high-end graphics card of the 200M series based on the G92b core. Therefore, the 55nm chip is essentially a 9800M GTX with slightly higher clock rates (550/1375/950 vs. 500/1250/800). As a result, the 260M is more similar to the desktop 9800GT than the GTX 260.

As with all native DirectX 10 cards, the GeForce GTX 260M renders 3D images using "Unified Shaders". Dedicated pixel shaders and vertex shaders have been replaced with 112 stream processors in the 260M, which now take over most of the graphics workload. The shader units themselves are also clocked higher (1375 MHz) than the core chip.

In general, the performance of the GTX 260M is somewhat higher than the 9800M GTX due to the higher clock speed. For current DirectX 10 games such as Crysis, World in Conflict, Bioshock or Age of Conan, the 260M is sufficient for gameplay under medium to high detail settings. Meanwhile, older games should be able to run fluently under high resolutions and full details. VRAM can be up to 1024 MB GDDR3 at 950MHz  in MXM 3.0 or 800MHz in MXM 2.0.

The GeForce GTX 260M integrates the PureVideo HD video decoder. The GPU is thus able to assist the CPU in the decoding of H.264-, VC-1-, MPEG2- and WMV9 videos.

HybridPower is a Windows Vista-only technology that allows users to switch between the integrated and dedicated graphics core for power-saving purposes. In the future, Nvidia intends to evolve the software for automatic switching depending on the active application (now known as Optimus). GeForceBoost is not supported with the GTX 260M as there would be no performance gain from combining with the integrated GPU.

The high current consumption of up to 75 Watts (of the entire MXM board) means that the GTX 260M can typically only be found in larger notebooks with loud and powerful cooling systems.

Compared with Desktop graphics cards, the GTX 260M is most similar to the GeForce 9800 GT.

NVIDIA GeForce GTX 285M SLI

The Nvidia GeForce GTX 285M SLI is a graphics solution that combines two Nvidia GeForce GTX 285M with an SLI connection. As not every game supports SLI efficiently, the performance increase compared to a single card is only about 0-40%. The most frequently used technique is Alternate Frame Rendering (AFR), where each card take turns rendering a frame in an alternating manner. Therefore, the SLI solution may suffer from noticeable micro stuttering at frame-rates between 20-30 fps (due to display irregularities between each rendered frame).

Each of the two GeForce GTX 285M is based on the G92b core and is therefore produced in 55nm. It features the full 128 pipelines of the G92b core and is therefore comparable to the desktop 9800M GTX+ and not the desktop GTX 280.

The Nvidia GeForce GTX 285M SLI in laptops with Core 2 Duo CPUs is bundled with the GeForce 9400M G chipset and therefore supports HybridPower (if the manufacturer enables it). With HybridPower, both GTX cards can be disabled and only the chipset graphics core can run, leading to improved battery life (and possibly less fan noise). Modern Core i7 laptops are using an Intel chipset and do not support HybridPower.

Since there are two GTX 285M cards active in SLI, the electrical current consumption and exhumed heat are about twice as much as what a single GTX 285M can produce. Due to the large power and cooling requirements, this SLI combination can only be found in large DTR laptops (like the Alienware M17x).