While Nvidia developers see a 100x speed increase, Intel only sees 14x with some kernels using CUDA.
A recent paper written by Intel and presented to the International Symposium on Computer Architecture in France claims that Nvidia's GeForce GTX 280 GPU is only 14x faster than its Core i7 960 processor. The paper attempts to debunk claims made by Nvidia developers who saw a 100x performance improvement in some application kernels using CUDA when compared to running them on a CPU.
But is that any surprise? GPUs like the Nvidia GTX 280 have 240 processing core--the average CPU only has six cores. However it's uncertain how Intel came to its "14x" conclusion, as the findings refer to a set of unknown benchmarks--Nvidia even pointed out that they weren't specified in the paper.
"[But] it's actually unclear...what codes were run and how they were compared between the GPU and CPU," said Nvidia spokesperson Andy Keane. "[Still], it wouldn't be the first time the industry has seen Intel using these types of claims with benchmarks."
Playing on the paper's title--Debunking the 100x GPU vs CPU Myth--Keane said that the real myth is that multi-core CPUs are easy for any developer to use and see performance improvements. "In contrast, [our] CUDA parallel computing architecture is a little over 3 years old and already hundreds of consumer, professional and scientific applications are seeing speedups ranging from 10 to 100x using Nvidia GPUs."
Naturally Intel retaliated, saying that Nvidia had taken one small part of the paper out of context and even added that GPU kernel performance is often exaggerated.
"General purpose processors such as the Intel Core i7 or the Intel Xeon are the best choice for the vast majority of applications, be they for the client, general or HPC market segments," said an Intel spokesperson. "This is because of the well-known Intel Architecture programming model, mature tools for software development and more robust performance across a wide range of workloads--not just certain application kernels."
To read the full Intel vs. Nvidia dispute, head here.