ATI Mobility Radeon HD 4650 vs AMD Radeon R6 (Mullins)

ATI Mobility Radeon HD 4650

The ATI Mobilty Radeon HD 4650 from AMD is a DirectX 10.1 middle-class notebook graphics adapter. Technically it is a slower clocked Mobility Radeon HD 4670. The successor of the HD 4650 is the Mobility Radeon HD 5650 with DirectX 11 support and improved performance. Later the HD 4650 was also introduced as Mobility Radeon HD 5165.

The gaming performance of the GPU lies a bit below the HD 4670. Most DirectX 9 games (like Call of Duty 4, F.E.A.R., or Unreal Tournament 3) should be playable in medium to high details (in 1024x768). Demanding DX10 games from 2008 like Crysis run only in low-medium details fluently.

The Mobility HD 4650 is based on the RV730 chip and features 320 stream processors (64 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.

A speciality of the Radeon HD 4600 Series is the possibility to use ordinary DDR2 and DDR3 graphic memory (as a cheaper alternative to GDDR3). However, cards that use that kind of memory will be slower than others equipped with GDDR RAM.

The Mobility Radeon HD 4650 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.

AMD published a current consumtion of about 15-25 Watt for the HD 4650. Still it is unclear if this value represents the chip alone or the whole mxm board including the memory (which would include about 5 Watt).

Compared to the desktop ATI Radeon HD 4650, the mobile counterpart features a slower chip and memory clock (575/800 versus 600/1000) and therefore performs a bit slower than the desktop 4650.

AMD Radeon R6 (Mullins)

The AMD Radeon R6 is an integrated DirectX 12 graphics card found in some AMD APUs (for example, the A10 Micro-6700T). It offers 128 shader cores across two Compute Units and is based on the GCN architecture. Core clock is rated at up to 500 MHz. The GPU does not have dedicated VRAM and will access main system memory (single-channel DDR3L-1333).

Using its UVD (Unified Video Decoder), the GPU can support the CPU when decoding videos up to 4K. The chip also integrates a specialized video encoder called VCE. Video streams can output via VGA, DVI, HDMI 1.4a and DisplayPort 1.2 to up to two external monitors.

The performance of the Radeon R6 is roughly equivalent to a Radeon HD 8280, as the GPU Boost is limited by the very low TDP. Typically, only older or very undemanding games will play fluently.