The ATI RADEON 8500 and 7500 Cards
In addition to the architectural specifications, it's also interesting to take a closer look at the physical card characteristics as well. Please note that the following descriptions refer to the two review cards we received and may not correspond exactly to all RADEON 8500 and 7500 products available.
Both the ATI RADEON 8500 and 7500 have a very similar look and feel, and even share the same quick install guide. The similarities relate to the physical nature of the products themselves, as both cards feature a full 64-MB of DDR memory and have very similar physical layouts. Each card also includes standard VGA and DVI outputs, along with basic S-Video TV-out option as well. Other than slight differences in the placement of these back panel outputs, the options are essentially the same. In fact, the GPUs on each card feature what appears to be a very similar heat-sink fan (HSF) unit as well. The two cards also share support for ATI's Hydravision software, which allows multiple monitor support in a variety of configurations.
Where they start to differ is in terms of card memory, with the RADEON 8500 sporting 3.6 ns Hynix memory while the RADEON 7500 includes ESMT 4 ns chips. By performing some quick math, we find the RADEON 8500 running right at the edge of the 3.6 ns rating (approximately 277 MHz). The 230 MHz memory speed of the RADEON 7500 would seem to have a bit more leeway with its 4 ns DDR memory having at least the potential of 250 MHz speeds. It is important to note that memory ratings may or may not translate into exact MHz speeds, depending on the brand and quality of the memory used.
Speaking of memory, the two RADEON cards also differ in their support of the Hyper-Z compression feature. The RADEON 8500 has support for the enhanced Hyper-Z II, while the RADEON 7500 will have to make due with the initial Hyper-Z. Since the RADEON 8500 is the newer GPU design, it also includes support for new or improved technologies such as Charisma Engine II (ATI's T&L engine), Pixel Tapestry II (programmable pixel shaders), SmartShader (programmable vertex shaders), TrueForm (introduce curved surfaces into triangle data), Hyper-Z II (improved pixel culling and Z-compression) and SMOOTHVISION (anti-aliasing).
For a more detailed examination of these features, please refer to our RADEON 8500 Preview.