Also, your "128 cuda cores" of Skylake variety run at higher frequencies and work off of much bigger caches, so they are faster (in serial manner)...
...until they are slower, because GPU's latency hiding mechanism (with occupancy) hides load latencies very well, while CPU just stalls the pipeline on every cache miss for ungodly amounts of time...
...until they are faster again when the shader program uses a lot of registers and GPU occupancy drops to the floor and latency hiding stops hiding that well.
Also, your "128 cuda cores" of Skylake variety run at higher frequencies and work off of much bigger caches, so they are faster (in serial manner)...
...until they are slower, because GPU's latency hiding mechanism (with occupancy) hides load latencies very well, while CPU just stalls the pipeline on every cache miss for ungodly amounts of time...
...until they are faster again when the shader program uses a lot of registers and GPU occupancy drops to the floor and latency hiding stops hiding that well.
But core counts - yes, more or less.