As we’ve seen, the number of ROPs has increased, but they haven’t gained any new features. But admittedly, the G8x ROPs were already quite complete, with support for 16- and 32-bit floating-point frame buffers with blending and antialiasing; antialiasing up to 8x or 16x in CSAA mode; Z rendering that’s eight times faster; etc. Not much needed to be added. So Nvidia made a point of optimizing performance. For blending in RGBA8 frame buffers, the G8x/G9x saw their performance divided in half, with 12 pixels per cycle. With the GT200 that limitation has been eliminated, with the addition of a 512-bit bus – with a bandwidth of more than 140 GB/s, the new ROPs should make the new GeForce cards unbeatable for fill rates. Here are the results for Z pixel rate:
As for raw performance, the results are no disappointment, setting a new record: 75,537 Mpixels/s! Still that’s a disappointing score in that it’s only a fourfold, and not an eightfold increase in the base fill rate. For the 9800 GTX, we posted a value of 5.2 – it was a little better, but again it remained well below the theoretical level.