NVIDIA GeForce GTX 485M SLI vs NVIDIA GeForce GTX 480M SLI

NVIDIA GeForce GTX 485M SLI

The NVIDIA GeForce GTX 485M SLI is a high-end laptop graphics solution based on two GTX 485M graphics cards. With SLI, each card usually renders a single frame (AFR mode). Therefore, it may suffer from micro stuttering in low fps ranges of 30fps. This happens because of different timespans between two frames (e.g. irregular delays between sequential frames).

The GeForce GTX485M SLI supports the same features as a single GTX 485M card. Therefore, it supports DirectX 11 and is produced in a 40nm fabrication process at TSMC. 

Unlike the GeForce GTX 480M, the 485M is no longer based on a trimmed down GF100 core, but on the GF104 core instead. The latter has been designed for the consumer sector and has 384 cores maximum if completely enabled. More information on the GF104 core can be found on the GTX 485M page.  

The performance of the Nvidia GeForce GTX 485M SLI is clearly better than the GTX 480M SLI and is therefore the fastest graphics solution for laptops as of early 2011. It allows the user to play all current games in high resolutions and detail settings with Antialiasing activated. Only Metro 2033 and Crysis may stutter with high Antialiasing and maximum details. Compared to a single GTX 485M, the performance from the SLI combination should be about 40% higher on average (with high details and Antialiasing). Compared to Crossfire solutions by AMD, the Nvdia SLI drivers have the advantage as of this writing.

As the GeForce 300M series, the GeForce GTX 485M supports PureVideo HD with VideoProcessor 4 (VP4 with Feature Set C). This means that the GPU is able to fully decode HD videos in H.254, VC-1, MPEG-2, and MPEG-4 ASP. Using Flash 10.1, the graphics card can also accelerate Flash videos.

What's new in the GF104 chips compared to the GF100 (480M) is the support for Bitstream transfer of HD Audio (Blu-Ray) via HDMI. Similar to the HD 5850, the GTX 485M can transmit Dolby True HD and DTS-HD via Bitstream to compatible receivers without quality loss.

The rendering cores of the Nvidia GeForce GTX 485M can be used for general calculations using CUDA or DirectCompute. In other words, the encoding for HD videos can be done significantly faster by using the shader cores of the GPUs instead of using modern CPUs. PhysX is also supported by the mobile Fermi to calculate physics effects in supported games. Furthermore, a single GTX485M can be used to calculate PhysX while the other card can render frames in the SLI setup.

Compared to desktop GPUs, the Geforce GTX 485M SLI is most similar to two Nvidia GeForce GTX 460 cards running in an SLI configuration.

NVIDIA GeForce GTX 480M SLI

The NVIDIA GeForce GTX 480M SLI is a high-end graphics solution for laptops based on two GTX 480M graphics cards in SLI mode. Each card usually renders a single frame in an alternating manner. Therefore, it may suffer from micro stuttering in low fps ranges of 30fps. This happens because of different timespans between two frames (e.g. Irregular delays between sequential frames).

The GeForce GTX480M SLI supports the same features as a single GTX 480M card. A single card is based on the Fermi architecture. Therefore, it supports DirectX 11 and is produced in 40nm at TSMC. Featuring 352 cores, the GTX480M is similar to the desktop GTX 465 but features a lower clock rate. The GeForce GTX 480M is combined with 2 GB of fast GDDR5 graphics memory (dedicated) and the overall performance should be superior to the Mobility Radeon HD 5870.

The GF100 aka. Fermi chip was redesigned from scratch and features 3 billion transistors (with all 512 shaders). Compared to the desktop Radeon HD 5870 with 2.13 billion transistors or the Mobility Radeon HD 5870 (RV870) with 1.04 billion transistors, the GTX480M chipset is quite large.

The mobile Fermi chip is stripped down to 352 shader cores (1-dimensional) with 32 ROPs and 44 Texture Units. The memory bus is 256 bit wide, but due to the fast GDDR5 memory, this should not be a bottleneck. The power consumption is specified with 100 Watt TDP including the MXM board and the 2 GB GDDR5. AMD usually specifies the TDP of the chip alone, therefore this value is not directly comparable. Still, the GTX 480M is only suited for very large DTR laptops with a good cooling system. Originally, only Clevo sold 17" (D901F) and 18" (X8100) barebone systems.

The fast performance of the Nvidia GeForce GTX 480M SLI is marginally better than two ATI Mobility Radeon HD 5870 in Crossfire Mode (CF), partly because of the superior driver support from Nvidia.  This means the GTX 480M SLI was the fastest graphics solution for laptops at the time of arrival (2010-06). It allows the user to play all current games in high resolutions and detail settings with Antialiasing activated. Only Metro 2033 and Crysis have to run at lower settings (see below).

Still, in some games the performance gain from SLI may be very small or sometimes a single card may be even a bit faster (due to no SLI support and overhead). You can still disable SLI through the drivers in this case. In our gaming tests, a single 480M was about 16% (Starcraft 2) to 48% (Far Cry 2) slower than the SLI combination. Otherwise, most modern games run about 40% slower on the single card compared to the SLI setup. (see expandable gaming charts below). Due to the fast tessellation unit, upcoming DirectX 11 games may have an advantage over the AMD 5000 series.

Similar to the GeForce 300M series, the GeForce GTX 480M supports PureVideo HD with VideoProcessor 4 (VP4 with Feature Set C). As a result, the GPU is able to fully decode HD videos in H.254, VC-1, MPEG-2, and MPEG-4 ASP. By using Flash 10.1 or later, the graphics card can also accelerate Flash videos, thus taking workload off of the CPU.

The rendering cores of the Nvidia GeForce GTX 480M can be used for general calculations by means of CUDA or DirectCompute. E.g., the encoding for HD videos can be done significantly faster by using the shader cores of the GPUs rather than using most modern CPUs. PhysX is also supported by the mobile Fermi to calculate physics effects in supported games. Furthermore, a single GTX480M can be used to calculate PhysX while the other card renders the game.

Compared to desktop GPUs, the Geforce GTX 480M is comparable to an underclocked Nvidia GeForce GTX 465 SLI combination (607/1200 clock speed).