Published in News
Boffins work out how to make GPU and CPU work together
by Nick Farrell on08 February 2012
Ebony and Ivory
Researchers from North Carolina State University have developed a new technique that allows graphics processing units (GPUs) and central processing units (CPUs) on a single chip to collaborate. They claim that the technique boosts processor performance by more than 20 percent.
Dr. Huiyang Zhou said that chip manufacturers are now creating processors that have a ‘fused architecture,’ meaning that they include CPUs and GPUs on a single chip. While this approach decreases manufacturing costs and makes computers more energy efficient, they still have not got the CPU and GPU cores working on the same functions. Chips rarely collaborate to execute any given program, so they aren’t as efficient as they could be.
GPUs were initially designed to execute graphics programs, and they are capable of executing many individual functions very quickly. CPUs have less computational power but are better able to perform more complex tasks. His method is to allow the GPU cores to execute computational functions, and have CPU cores pre-fetch the data the GPUs will need from off-chip main memory.
This is more efficient because it allows CPUs and GPUs to do what they are good at. CPUs and GPUs fetch data from off-chip main memory at approximately the same speed, but GPUs can execute the functions that use that data more quickly. So, if a CPU determines what data a GPU will need in advance, and fetches it from off-chip main memory, that allows the GPU to focus on executing the functions themselves – and the overall process takes less time, he said.