The timer fires approximately 30 times per second and my scroll velocity is 30 pps (pixels per second). (...) I have tried a few things to improve the drawing: 1. higher refresh rate (60, 90 Hz), no effect 2. very high refresh rate with culling (high frequency timer, skip drawing calls to emulate 30 frames per second, sort of a wall clock technique), no effect 3. wrote a sample using a programmatic NSClipView to scroll the items, no effect 4. renice the process to real time priority (renice -20 -p <pid>), no effect
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