To make these graphs, place the screen resolution on the X-axis (in Mpixels). E.g. 640x480 => 640*480=307.200 pixels or 0.3072 Mpixels. On the Y-axis you place the number of Mpixels per second. That's thus the number on the X-axis multiplied with the benchmark result (in frames per second). The result is in Mpixels/second.

The general rule is the higher the number, the better. The left side usually shows you how good the driver is. Higher means a lower CPU load (better driver). The right side usually shows you fill-rate limits as a plateau. Again, the higher the better. A higher plateau means that the hardware can draw more pixels to the screen per second, which could be due to better hardware, especially better caching, more memory bandwidth, a higher clockspeed or a general better efficiency.

Different CPUs will result in a horizontal shift of the curve. A faster CPU will move the curve to the left while a slower CPU will move the curve to the right. Differences between 3D boards are usually shown in differences in height (vertical movement). Sudden unexpected shifts in the curve usually point at an inefficiency, a hard limit like texture trashing, a failing cache, texture uploads, or even an in-software emulated effect.

Questions and Comments

I personally believe that these graphs tell much more than just a table with numbers; they reveal extra details that are hidden in the table. The graph introduced shows these facts very clearly, and also reveal weird things that might have remained unnoticed when just using the tables. For example, the sudden impact of texture uploads or rendering via the AGP bus is very visible using this method.

If you have any questions or comments about this representation, do not hesitate to contact me here or make a post in the forum here.

For the record, the first time I saw this representation technique was in a forum post by Simon Fenney. Simon is one of the research and development guys of Videologic and he used this graph type to show the difference in CPU load between PVR250, TNT2, and Voodoo3. You can find that post here. Now on to the benchmarks of the 3dfx Voodoo3