AMD Radeon HD 6830M vs AMD Radeon HD 6870M

AMD Radeon HD 6830M

The AMD Radeon HD 6830M or ATI Mobility Radeon HD 6830 is a performance class DirectX 11 capable graphics card for laptops / notebooks by AMD. Technically the HD6830M is a slightly higher clocked Mobility Radeon HD 5830 with the same features (same chip). As all cards of the Mobility HD 5800 / 6800M series, the HD 6830M is based on the desktop HD 5770 (RV840) chip. 

The memory interface of the 6830 is composed out of two 64 bit wide controllers leading to a 128 bit memory bus that can access up to 1024 MB of DDR3. Because of the small bus width and the lack of GDDR5 memory, the memory performance should be the bottleneck of this card.

The 6830M offers 800 MADD cores (called Stream Processors) which are grouped in 160 5-dimensional groups. The cores support DirectX 11 functions in hardware (Tessellation, OIT, Post-Processing, Shadows, HDR Texture Compression) and offer a theoretical calculation power of 0.92 TFLOPs. Furthermore, 16 ROPs, 40TMUs, and 40 TAUs can be found on the chip. 

For general computing, the graphics core can be accessed using ATI stream, OpenCL, and DirectCompute 11.

The gaming performance of the 6830M should be somewhere between a HD 5830 and 5850M/6550M with DDR3 memory. That means the GPU power should be not sufficient for demanding games like Metro 2033, Call of Duty Black Ops or Mafia 2 to play in highest detail settings and high resolutions. However, without AA and in 1366x768 the games should run fine.

The Mobility Radeon HD 6800M series includes the old video processor UVD2 to decode HD videos with the graphic card. It supports only VC-1, H.264 and MPEG-2 but not DivX and the variants like the new UVD3 in the 6900M series. Since the Flash 10.1, the 6800M series is also able to help accelerate Flash HD videos (like YouTube).

As the 5830, the 6830M is able to transmit HD audio formats (like Dolby True HD or DTS HD Master Audio) with up to 8 channels and 192 kHz / 24 Bit over HDMI 1.3a.

The 6830M still supports just the original Eyefinity (and not the improved Eyefinity+) to connect up to 6 monitors to the graphics chip (if the laptop vendor offers DisplayPorts on the laptop). 

The power consumption should be similar to the old 5730 about 24 Watt (according to AMD) and therefore suited for 15-17" laptops.

AMD Radeon HD 6870M

The AMD Radeon HD 6870M or ATI Mobility Radeon HD 6870 is a high-end DirectX 11 capable graphics card for laptops by AMD. It is essentially an ATI Mobility Radeon HD 5870 with a slightly slower core clock rate. Therefore, performance and features (such as UVD2 and Eyefinity) are similar to the old card.

The memory interface of the Mobility 6870 is composed of two 64 bit wide controllers leading to a 128 bit memory bus that can access up to 1024 MB or 512 MB of  GDDR5 and GDDR3 memory, respectively. The performance of the 6870M suffers noticeably if (G)DDR3 is used by the laptop vendor.

The HD 6870M offers 800 MADD cores (called Stream Processors) which are grouped in 160 5-dimensional groups. The cores support DirectX 11 functions in hardware (Tessellation, OIT, Post-Processing, Shadows, HDR Texture Compression). Furthermore, 16 ROPs, 40TMUs, and 40 TAUs can all be found on the chip. The approximately 1040 Million transistors of the GPU offer a theoretic computational power of up to 1.08 TFLOPS (compared to 1.12 TFLOPS of the 5870M). 

For general computing, the graphics core can be accessed using ATI stream, OpenCL or DirectCompute 11.

The gaming performance of the GPU should be similar to the HD 5870 and therefore sufficient for all current games (2010) in high resolution and high detail settings ( with the exception of Metro 2033 and Crysis). Detailed gaming benchmarks can be found on the HD 5870 page.

The Mobility Radeon HD 6800M series includes the old video processor UVD2 to decode HD videos with the graphics card. It supports only VC-1, H.264 and MPEG-2, but not DivX and other variants such as those supported in the new UVD3 in the 6900M series. Beginning with Flash 10.1, the 6800M series has also been able to accelerate Flash HD videos (like YouTube), which ultimately takes workload off of the CPU.

As the 5870, the 6870M is able to transmit HD audio formats (like Dolby True HD or DTS HD Master Audio) with up to 8 channels and 192 kHz / 24 Bit over HDMI 1.3a.

The 6870M still only supports the original Eyefinity (and not the improved Eyefinity+) to connect up to 6 monitors to the graphics chip. Of course, the ability to connect 6 monitors simultaneously will depend on the laptop vendor and the availability of DisplayPorts.

Due to the high power consumption of the Mobility Radeon HD 6870M, it is normally only suited for large laptops with good (and possibly loud) cooling solutions. 

Compared to desktop graphics cards, the Mobility Radeon HD 6870M should perform somewhere between a Radeon HD 5750 and 5770, at least according to the specs.