But how many times can you access the DRAM in that time? One thing you have to keep in mind is that the more dynamic the scene graph, and the larger its memory

But how many times can you access the DRAM in that time? One thing you have to keep in mind is that the more dynamic the scene graph, and the larger its memory footprint, the more frequent you'll miss the cache while traversing it. It's possible to manually write optimized flex-box-like layout code, where the overall structure, if not exact position, is mostly static. For example, if you always have one resizable panel to the side of two viewports, of equal width (as is the case in the editor I use atm), you can easily do `viewport_width = (total_width - panel_width) / 2` and be done. Those operations, if done with integers, should be faster than a read from cache, or if done with floating-point numbers, (much) faster than going to DRAM in the even of a cache miss. However, doing all of that by hand would be a pain, and it's hopeless in the face of user customization. SIMD is another resource that's completely unusable in the face of truly dynamic data, and a time sink to do manually. What we're missing is automation of mostly-static UIs, generating specialized code and optimizing it into computations that run under a microsecond. For HTML, the hope would be JITs, but highly dynamic DOMs are still all over the place, so you're not going to have as many gains as a dedicated UI system, and it wouldn't be free for the user.