AMD/ATI has released two new high-end graphics chips recently, Radeon HD 4870 and Radeon HD 4850, known by the codenames RV770 XT and RV770 PRO, respectively. As you can guess by the numbers, HD 4870 provides a higher performance compared to HD 4850 and currently is the fastest GPU provided by AMD/ATI – until Radeon HD 4870 X2, a video card featuring two HD 4870, is launched. In this review we will benchmark HD 4870 from Sapphire and compare it to its main competitors from NVIDIA. Is this video card a good buy? Check it out.
Sapphire HD 4870 follows AMD/ATI’s reference model both on its physical aspect as in specifications: the graphics chip runs at 750 MHz with its memory being accessed at 900 MHz (real clock) through a 256-bit memory interface. Just for a quick comparison, HD 4850 runs at 625 MHz and has its memory running at 993 MHz.
But what is really new on HD 4870 is the use of the new GDDR5 memory, which transfers four data per clock cycle instead of two like it happens on DDR through GDDR3 technologies. Because of that the memories achieve a performance as if they were working at 3.6 GHz, pumping data transfer rate up to 115.2 GB/s (these numbers for HD 4850 are 1,986 MHz and 63.5 GB/s, respectively).
Both new chips are based on DirectX 10.1 (Shader 4.1) architecture, where all processing units inside the graphics chip is generic, being able to process any kind of vector (pixel shader, vertex shader, etc). What is really impressive about these two new chips is that they both have 800 processing units inside the chip. We will provide a short table comparing the specs from this new video card with the specs from its main competitors. Before that, let’s take an overall look at Sapphire HD 4870.
This video card requires the installation of two 6-pin auxiliary power connectors, see in Figure 4. The product comes with two adapters for you to convert standard peripheral power plugs into a 6-pin power plug if your power supply doesn’t provide them. At least this time AMD decided to stick with the 6-pin connector instead of using the 8-pin one, which isn’t found on the majority of power supplies.