ATI Mobility Radeon HD 4850 vs NVIDIA Quadro K1100M

ATI Mobility Radeon HD 4850

The ATI Mobilty Radeon HD 4850 from AMD is a DirectX 10.1 upper middle-class notebook graphics adapter. Technically, the GPU is based on the desktop HD 4850 GPU but with a lower clock rate for reduced energy consumption.

The gaming performance of the ATI Mobility Radeon HD 4850 should be comparable to the desktop HD 4830 and is therefore very good at resolutions below 1080p. The high amount of shaders and the wide 256 bit bus can allow the card to run practically every DirectX 9 game in high resolutions and details. Demanding DirectX 10 games, such as Crysis, can be played with medium to high detail settings. Compared to an Nvidia GeForce GTX 260M, the HD 4850 should be a bit faster on average.

The newer Mobility HD 5850 is noticeably faster than the Mobility HD 4850 if GDDR5 graphics memory is present. If DDR3 with a smaller 128 Bit memory bus is used instead, then this would bottlebeck the 5850 to performance levels closer to that of the Mobility HD 4850.

The mobile HD 4850 core is based on the RV770 chip and features 800 stream processors (or 160 5-dimensional shader cores). These cores do the graphics work previously done by dedicated shader and pixel pipelines of older GPUs. The stream processors (also called ALUs) are grouped in five-way VLIW units. Each of the five instructions of a VLIW bundle has to be independent from the others, so the overall performance is highly dependent on driver optimizations.

The Mobility Radeon HD 4850 includes UVD 2, Avivo HD software and an onboard soundchip for 7.1 sound output over HDMI or DisplayPort. UVD 2 supports full bitstream decoding of H.264/MPEG-4 AVC and VC-1 streams by the GPU, thus reducing workload from the CPU. In addition to this, the software also supports dual video stream decoding and Picture-in Picture mode for full compliancy to the UVD BD-Live standards. Simply put, the Avivo HD technology is able to handle most video tasks and enables the GPU to decode HD videos.

AMD has claimed a current consumption of about 45-65 Watt for the cards part of the mobile HD 4850 to HD 4870 range. Still, it is unclear if this value represents the core chip alone or the entire MXM board with memory modules. We estimate that the VRAM chips would contribute about 5 Watts total to the overall energy demands of the mobile HD 4850.

Compared to the desktop ATI Radeon HD 4850, the mobile 4850 features a slower core clock and is therefore more similar to the desktop HD 4830 in terms of overall performance.

NVIDIA Quadro K1100M

The NVIDIA Quadro K1100M is a DirectX 11 and OpenGL 4.3 compatible graphics card for mobile workstations. It is a Kepler-based GPU built on the GK107 chip with all 384 shader cores activated and manufactured in 28nm at TSMC. The Quadro K1100M is built for the Intel Shark Bay generation (Haswell) and is a successor to the Quadro K1000M (Chief River platform). As a new feature, PCIe 3.0 is supported for the first time. The K1100M usually comes with 2 GB GDDR5 VRAM clocked at 700 MHz (2800 MHz effective, 44.8 GB/s). 

The Quadro series offers certified drivers that are optimized for stability and performance in professional applications like CAD or DCC. OpenGL performance, for example, should be significantly better than with GeForce graphics cards of similar specifications.

Architecture

The Kepler architecture is the successor to the Fermi architecture that first appeared in laptops with the GeForce 400M series. The GK107 Kepler core offers two shader blocks, called SMX, that are clocked at the same speed as the central core. In the K1100M, both blocks are active leading to the 384 CUDA cores. Although more shader cores are available in the Kepler architecture as compared to the Fermi design, the Kepler shaders are still expected to be up to twice as power efficient. However, due to the missing hot clock of the shader domain, two shaders of a Kepler chip offer similar performance to just one shader of a Fermi chip (as the latter is clocked twice as fast).

Performance

The performance is similar to the old Quadro K2000M and clearly superior to the Quadro K1000M. This places the K1100M in range of the consumer GeForce GT 740M and GT 645M GPUs. Most demanding games of 2013 will run fluently with medium details and resolutions.

Features

The improved feature set now includes support for up to 4 active displays. Furthermore, high resolution monitors of up to 3840 x 2160 pixels can now be connected using DisplayPort 1.2 or HDMI 1.4a if available. HD-Audio codecs, such as Dolby TrueHD and DTS-HD, can be transmitted via bitstream mode through the HDMI port. However, as most laptops will feature Optimus, the integrated GPU will likely have direct control over the display ports and may limit the feature set available by the Nvidia Kepler cards.

Using CUDA or OpenCL 1.2, the cores of the Quadro K1100M can be used for general calculations.

The 5th generation PureVideo HD video processor (VP5) is also integrated in the GK107 core and offers hardware decoding of HD videos. Common codecs such as MPEG-1/2, MPEG-4 ASP, H.264 and VC1/WMV9 are fully supported up to 4K resolutions while VC1 and MPEG-4 are supported up to 1080p. Two streams can be decoded in parallel for features such as Picture-in-Picture. Another novelty is the inclusion of a dedicated video encoding engine similar to Intel QuickSync that can be accessed by the NVENC API.

The power consumption of the Quadro K1100M is rated at a TGP of 45 W including the board and memory components. Therefore, the card is suited for medium-sized notebooks with 15-inch displays or greater.