I followed your math, but not your conclusion! Say we use your example of H = 2L. Then we have R_s = L / (2L - L) * R_a, or R_s = R_a. Sure. Now say we double

I followed your math, but not your conclusion! Say we use your example of H = 2L. Then we have R_s = L / (2L - L) * R_a, or R_s = R_a. Sure. Now say we double the heap: H = 4L. Then we have R_s = L / (4L - L) * R_a, or R_s = R_a/3. For a fixed allocation rate, increasing the heap makes the scan rate go down, i.e. we scan less often. It seems like you're assuming that the live set is a fixed fraction of the heap size, but that doesn't make sense to me. The size of the live set is a function of what the program does, not its heap size.