What Kind of GPU Are You?

In the old days, big computers often had some form of external array processor. The idea is you could load a bunch of numbers into the processor and then do some math operations on all of the numbers in parallel. These days, you are more likely to turn to your graphics card for number crunching support. You’ll usually use some library to help you do that, but things are always better when you understand what’s going on under the hood. That’s why we enjoyed [RasterGrid’s] post on GPU architecture types.

If you can tell the difference between IMR (immediate mode) and TBR (tile-based) rendering this might not be the post for you. But while we knew the terms, we found a lot of interesting detail including some graphics and pseudo code that clarified the key differences.

Which architecture is better? As the post points out, that depends on how you define better. Each can boast it is better at something, but the flip side is that each is also worse at something else. In general, IMR GPUs wind up in desktop computers and mobile devices tend towards TBR. It also depends on the specific task you ask of the GPU.

Granted, you normally don’t need to know any of this. For graphics, you are probably not directly controlling the device and for computation, you will likely use CUDA or OpenCL. But you don’t need to understand an engine to drive a car, but the best-performing drivers do know how an engine works.