Radeon HD 7950

Physically, the Radeon HD 7950 is identical to the Radeon HD 7970, with the exception of one distinguishing feature: both auxiliary power connectors are six-pin (6-pin). This is the result of lower power consumption: the maximum is less than 225W (75W PCI-E bus powered, plus 75W from each 6-pin connector). In fact, AMD is talking about a TDP of 200W. For comparison, the Radeon HD 7970 has a TDP of 250 W, which explains the presence of one six-pin and one eight-pin connector in the older model. The board is 26.25 cm (10.5 inches) long, but add half an inch to that because of the metal base and plastic shroud. This must be taken into account when choosing a case, since the card turned out to be very long.

As in the Radeon HD 7970, the cooling system uses one centrifugal fan, located on the opposite edge of the board from the connector panel. It drives air through the entire board and out through the grate on the connector panel. We like this cooling design, but it is impossible to implement when it comes to dual-processor cards such as the Radeon HD 6990 and GeForce GTX 590. In both cases, the cooler is located in the center of the board, so only part of the hot air is vented through the back wall and cooling is less efficient .

Radeon HD 7950 Specifications 

The Radeon HD 7950 is based on the same Tahiti GPU as the more expensive flagship HD 7970. The Tahiti GPU has 4.31 billion transistors and is manufactured using a 28nm process. However, instead of 32 computing units (CU - Compute Unite), the junior model has 28 CU units. As we already know from the HD 7970 review, each CU includes four vector units, each of which has 16 stream processors (shaders, ALUs - call it what you want). Thus, we have 64 stream processors per CU. If we simply multiply the number of stream processors in the CU by the number of compute units themselves, then we get 1792 stream processors (64x28) per core.

And since each CU has four texture units, their total number is reduced from 128 to 112 compared to the HD 7970. To further differentiate the Radeon HD 7950 from the older model, AMD lowered the core frequency to 800 MHz (for example, in the Radeon HD 7970 core runs at 925 MHz). Peak GPU compute performance dropped from 3.70 TFLOPS to 2.87 TFLOPS.

The renderer is CU independent, so AMD retained all eight ROPs, allowing up to 32 ROPs per cycle. Six 64-bit memory controllers are connected to rasterizers via a common interface. Thus, we get a 384-bit memory bus in combination with 3 GB GDDR5 graphics memory, operating at a frequency of 1250 MHz. This provides a throughput of 240 GB/s.