The overall average sits at 100%, which is misleading. The picture is split: anything the ET4000 can accelerate (text, graphics drawing) runs significantly faster, while GEM-level operations that still go through the CPU (window management, scrolling, blitting) are dragged down by the overhead of driving a higher resolution through the ISA bus. In day-to-day use, the VDI gains are what you see and feel: text is crisp, menus pop up quickly, and drawing applications are noticeably more responsive.
+The overall average sits at 100%, which is misleading. The picture is split: anything the ET4000 can accelerate (text, graphics drawing) runs significantly faster, while GEM-level operations that still go through the CPU (window management, scrolling, blitting) are dragged down by the overhead of driving a higher resolution through the ISA bus. Running at 1024x768 with 256 colors means 7.5 times the pixel count and 15 times the data volume compared to ST High (640x400 in 2 colors). The Nova driver without NVDI squeezes the maximum out of this particular card and driver combination. In day-to-day use, the VDI gains are what you see and feel: text is crisp, menus pop up quickly, and drawing applications are noticeably more responsive.
FPGA cores on MiSTer and MiST still only emulate the native ST Shifter, with no ET4000 emulation on the horizon given the FPGA resources it would require. So the real hardware approach remains the only way to get those higher resolutions, and now it works in the Mega ST 4 "High" machine with its dedicated monitor.