NVIDIA GeForce GTX 285M SLI vs NVIDIA GeForce GTX 280M
NVIDIA GeForce GTX 285M SLI► remove from comparison
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).
NVIDIA GeForce GTX 280M► remove from comparison
The NVidia GeForce GTX 280M is a high-end graphics card as part of the 200M series and is based on the G92b core (Desktop GeForce 9800 GTX+). Therefore, it is actually more related to the GeForce 9800 GTX+, both performance-wise and architecturally, than to the GTX 280. The chip is produced in 55nm with all 128 pipelines enabled, as opposed to the GT 9800M with only 112 pipelines produced in a 65nm process.
Hybrid Power makes an appearance on the GTX 280M as well, but with much improved performance. Switch times on the graphics card now completes in just a fraction of a second, compared to a full 7 seconds on the 9800M GTX,
As with all DirectX 10 graphics cards, the GeForce GTX 280M renders 3D images using "Unified Shaders". Dedicated pixel and vertex shaders of yesteryear are gone in favor of 128 stream processors running at 1250MHz on the GTX 280M. The stream processors handle all of the workload that would have otherwise been processed by pixel or vertex shaders. VRAM can be up to 1024 MB GDDR3 clocked at either 800MHz (on MXM2 boards) or 950MHz (on MXM3 boards).
Due to the full 128 shader cores, the GTX 280M is about 10-25% faster than the older 9800M GTX and slightly faster than the 260M. Compared to the performance of the Mobility Radeon HD 4870, the GTX 280M is about equal in synthetic benchmarks, if not slightly lower. The Nvidia card, however, has proven to be slightly faster in games, so the GTX 280M can therefore be rated more highly in terms of real-life performance. Specifically, games with PhysX support (e.g., Mirrors Edge) can have significant performance advantages if PhysX effects are enabled.
Another feature of the GeForce GTX 280M is the integrated PureVideo HD video processor. The card is able to assist the CPU in decoding of H.264-, VC-1-, MPEG2- and WMV9 video material.
HybridPower is a Windows Vista-only technique used to switch between the integrated (only with Nvidia chipset) and dedicated graphics cores for power-saving purposes. Eventually, Nvidia will have its future chips switch automatically between dedicated or integrated through drivers (now known as Optimus Technology). GeForceBoost is not supported with this card, as there would be no performance gain from combining the integrated GPU with the discrete video card.
A high power consumption of up to 75 Watts (including the VRAM and MXM board) means that only large notebooks with powerful (and possibly loud) cooling systems can run the GTX 280M.
The newer GTX 285M is based on the same core as the GTX 280M, but with only slightly altered clock rates. As a result, the performance of the GeForce GTX285M is very similar to the GTX 280M.
Compared with Desktop graphic cards, the performance can be considered somewhere in between the 9800 GT and the 9800 GTX, the latter of which has considerably higher clock rates at 675/1675/1100MHz.
|NVIDIA GeForce GTX 285M SLI||NVIDIA GeForce GTX 280M|
|GeForce GTX 200M Series|
|Pipelines||256 - unified||128 - unified|
|Core Speed||576 MHz||585 MHz|
|Shader Speed||1500 MHz||1463 MHz|
|Memory Speed||1020 MHz||950 MHz|
|Memory Bus Width||256 Bit||256 Bit|
|Max. Amount of Memory||2048 (2x1024) MB||1024 MB|
|DirectX||DirectX 10, Shader 4.0||DirectX 10, Shader 4.0|
|Transistors||1508 Million||754 Million|
|technology||55 nm||55 nm|
|Features||HybridPower, PureVideo HD, CUDA, PhysX ready||HybridPower, PureVideo HD, CUDA, PhysX ready|
|Date of Announcement||02.03.2009||02.03.2009|
|Information||MXM 3||MXM 3|
|Link to Manufacturer Page||http://www.nvidia.com/object/product_gef...||http://www.nvidia.com/object/product_gef...|
3DM Vant. Perf. total + NVIDIA GeForce GTX 285M SLI