there are corner cases that need to be figured out even with this model
1. if you have a CPU hog, how well/poorly does it work if you have one core that is 2x (or 10x) the power of a different core? can your cpu hog get stuck on a slow core?
2. how do you deal with software that will adapt to not having enough processor
3. what about software that's constrained by memory bandwidth, not cpu cycles, it may be just as fast on a slow core as a fast one, but use 100% cpu in both cases (since CPU utilisation doesn't reflect time spent waiting for memory access)