The Real Cost of Moving Pixels
Years ago I was working at an embedded software company, profiling a 2D graphics renderer running on an ARM processor. We were trying to squeeze more frames per second out of a UI that frankly didn’t look that complex: a few icons, some solid-color panels, the occasional gradient. Nothing that should have been slow. The profiler told a different story. The renderer was spending most of its time not computing. Just reading. Fetching pixels out of external DRAM, one scanline at a time, pushing them through compositing, writing them back. The CPU sat there waiting. We weren’t compute-bound. We were memory-bound. Almost every optimization instinct I had from years of server-side work was pointing me in the wrong direction. ...