"Well GPU main memory is L2. CPU main memory is L3. Which is why GPUs are so much faster." - cs major in my college.

Someone please confirm if this is a common opinion.

I suppose it depends on the task assigned to it, GPU's are exceptional at floating point operations where as CPU's are more general purpose.

And the main difference is the architecture.

Gpus are designed to solve huge amount of small operations, and cpus are incredibly fast at solving single operatons.

Gpus are great for parallelism and cpus do better in serial implementation.

But parallelism in gpus shouldn't be mixed with the one in multicore cpus, as gpus can execute as much as 1000 threads at the same time leading to new concepts in programming.