After taking a look at the RADEON X1600 XT product earlier this week in our architectural preview (for details see our article called ATI RADEON X1000: Brand-New Graphics Architecture from ATI Explored ) of the RADEON X1000 we were impressed by its performance in pixel shader 3.0 branching and some other tests, but were left curious about real-world performance of a graphics processing unit (GPU) that has 12 pixel processors and only for 4 texture units.
The RADEON X1600-series is expected to substitute RADEON X700 family of graphics chips as well as to replace the RADEON X800 GT and possibly the RADEON X800 XL (or GTO2) products from performance mainstream segment. The obvious advantage the RADEON X1600 has over predecessors is support for Shader Model 3.0, HDR and some other technologies. The probably disadvantage is 128-bit memory bus as well as pretty low texel-rate. We will find out the outcome later in the article, but now let’s summarize everything we know about the RADEON X1600 also known as RV530, based on the results in synthetic investigation.
- ATI RADEON X1600-series has some nice performance in pixel shaders 2.0 due to high clock-speeds. Probably, the RADEON X1600 XT model will be faster than numerous performance-mainstream and mainstream parts in games limited by pixel shaders.
- Unfortunately, modern games, which may be limited by pixel shader 2.0 performance, also use loads of textures and there are only four texture units in the RADEON X1600-series. In case there are many textures, the RADEON X1600 is likely to be limited by texel rate rather than pixel shader performance.
- Due to 90nm process technology clock-speeds of the RADEON X1600-series are expected to grow, however, ATI’s ability to push the speeds of the RADEON X1600 from 590MHz should not be overestimated: by early October the company still only had Engineering Samples of the RV530 chips.
- Just like in the case of the more sophisticated RADEON X1800-series, ATI implemented Ultra-Threading Dispatch Processor that distributes pixel shader workload among the pixel processors and makes efficient use of pixel processors’ arithmetic logic units (ALUs). ATI says that this architecture helps to achieve a 90% efficiency of the pixel processors on any shader.
- The RADEON X1600 fully utilizes Ring Bus memory architecture , but since the part has 128-bit memory controller, Ring Bus is 256-bit wide. The model 1600 XT uses GDDR3 memory at 1.38GHz, which provides about 22GB/s bandwidth.
- Due to thinner manufacturing process, the RADEON X1600 XT only consumes about 42W , down 8W from the RADEON X800 XL, which has similar amount of transistors and lower clock speeds.
- Just like the more powerful RADEON X1800 brother, the X1600-series can render images in HDR modes and apply FSAA to them, has improved quality anisotropic filtering and also features Avivo, a video processor featuring hardware-accelerated H.264 decoding, a codec used on next-generation DVD discs, as well as improved video quality.