If the disk can process the data at 1GB/s, the CPU can process the data at 2GB/s, the GPU can process the data at 32GB/s, then the CPU can process the data at 1GB/s and the GPU can process the data at 1GB/s.
(also, personally, "large dataset" is a short way to say "doesn't fit in memory". if it fits in memory it's small, if it doesn't fit in memory it's large. but that's just my opinion. I generally avoid calling something a "large" or "small" dataset because it's an overloaded term that means different things to different people.)
You're yada-yada-yadaing the best part.
If the disk can process the data at 1GB/s, the CPU can process the data at 2GB/s, the GPU can process the data at 32GB/s, then the CPU can process the data at 1GB/s and the GPU can process the data at 1GB/s.
(also, personally, "large dataset" is a short way to say "doesn't fit in memory". if it fits in memory it's small, if it doesn't fit in memory it's large. but that's just my opinion. I generally avoid calling something a "large" or "small" dataset because it's an overloaded term that means different things to different people.)