ATI Mobility Radeon HD 4830 vs NVIDIA Quadro K4000M

ATI Mobility Radeon HD 4830

The AMD ATI Mobility Radeon HD 4830 is a slower clocked Mobility HD 4860 and based on the 40nm RV740 core. Therefore, it is similar to the desktop HD 4700 series. Because of the 40nm production process, the power consumption should be similar to the HD 4670 (according to rumors).

Instead of GDDR5 memory of the HD 4860, the 4830 can be only equipped with slow DDR3 or faster GDDR3. Therefore, the 128 Bit memory bus becomes a bottle neck and the performance is clearly degraded.

The gaming performance of the ATI Mobility Radeon HD4830 is sufficient for demanding games of 2009 in medium - high details. Our gaming benchmarks (see below) showed that a high preset in Crysis or NFS Shift resulted in barely playable framerates around 25 fps. Less demanding games, are playable in high resolution and detail settings.

The Mobility HD 4830 is based on the RV740 chip and features 640 stream processors (128 5-dimensional shader cores). These cores do the graphic work of the shader- and pixel pipelines of older GPUs. The stream processors are also called ALUs and are grouped in five-way VLIW units. Each of the five instructions of a VLIW bundle has to be independent from the others and therefore the performance depends on the optimization of the driver.

The Mobility Radeon HD 4830 includes the Avivo HD called video technology including an onboard soundchip for 7.1 sound output over HDMI or DisplayPort and the 2nd generation UVD (Unified Video Decoder). This UVD 2 supports full bitstream decoding of H.264/MPEG-4 AVC and VC-1 streams. In addition to this, it also supports dual video stream decoding and Picture-in Picture mode which makes the UVD full BD-Live compliant. Simplified, the Avivo HD technology handles all video tasks and enables the GPU to decode HD videos.

The HD4830 was replaced by the Mobility Radeon HD 5830, which features a higher shader count (800) and DirectX 11 capable shaders. Therefore, the gaming performance of the 5830 is better, but also the power consumption should be higher (same 40nm process, although more mature).

Compared to the desktop cards, the Mobility Radeon is similar to the ATI Radeon HD 4730. Still, the desktop 4730 offers a noticeable higher performance due to GDDR5 usage and higher clock speeds.

NVIDIA Quadro K4000M

The NVIDIA Quadro K4000M is a high-end, DirectX 11.1 compatible graphics card for mobile workstations. It is a Kepler-based GPU built on the GK104 chip (but using only 960 shader cores) and is manufactured in 28nm at TSMC. The Quadro K4000M is built for the Intel Chief River generation (Ivy Bridge) and is the successor to the Fermi-based Quadro 4000M (Huron River platform).

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 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 GK104 Kepler core offers eight shader blocks, called SMX, that are clocked at the same speed as the central core. In the K4000M, 5 blocks are active leading to the 960 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). 

PCIe 3.0 is now supported by the mobile Kepler series and an optional Turbo mode can automatically overclock the Nvidia card by a theoretical 15 percent if the laptop cooling system allows it. The implementation of this boost mode is done in the BIOS, but it is ultimately dependent upon the manufacturer of the laptop.

Performance

The performance is significantly above the level of the older Quadro 5010M and also beats the GeForce GTX 675M. Therefore, the card will manage both CAD software and demanding 3D games of 2013 in high quality settings.

Features

The improved feature set now includes support for up to 4 active displays. Furthermore, high resolution monitors of up to 3840x2160 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.

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 K4000M is rated at 100 Watt (TGP according to Nvidia) and is therefore suited for large-sized notebooks 17-inches or greater.