WARF: P140398US01

Memory Controller for Heterogeneous Processors


Nam Sung Kim, Hao Wang

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing a method to improve memory access in common heterogeneous computers having a CPU and a GPU.
OVERVIEWMany modern computers employ multiple processor types, for example, one or more conventional CPUs operating in tandem with specialized GPUs, the latter tailored to high-speed streaming processing.

The performance of these systems is limited by the speed of off-chip memory access. One method to improve speed is to prioritize access to CPU cores because they represent a smaller proportion of memory accesses and are less able to tolerate long access latency. In contrast, GPUs can offset long latency.

Deciding how to prioritize memory access between the two types of processors can be difficult because the relative importance of each task is unknown. The imperfect solution has been to rely on a ‘fairness’ system in which each processor is guaranteed a minimum amount of memory access.
THE INVENTIONUW–Madison researchers have developed a memory controller providing improved access to common memory when a single parallel application is divided between different processor types, e.g., a CPU and a GPU. In these instances, fairness may not be a primary consideration and performance can be evaluated in terms of completing the entire application.

The controller works by dynamically adjusting access priorities between the different processors. It can predict sequential memory accesses by the processor having higher memory latency or fewer access requests to lockout the other processor during those sequences.
  • Hardware and firmware to improve execution of single parallel programs running on heterogeneous processors
  • Improves memory access and performance
  • Dynamic and flexible
  • Can be implemented with existing hardware/minor modifications
  • Accommodates changing program behavior to promote high priority memory access requests
  • No undue delay on low priority access requests
STAGE OF DEVELOPMENTThe new scheme achieves nearly 10 percent higher throughput than previous techniques. By employing several optimizations, an additional eight percent higher throughput can be achieved compared to FR-FCFS techniques (first-ready first-come-first-service).
Contact Information
For current licensing status, please contact Jeanine Burmania at or 608-960-9846.
The WARF Advantage

Since its founding in 1925 as the patenting and licensing organization for the University of Wisconsin-Madison, WARF has been working with business and industry to transform university research into products that benefit society. WARF intellectual property managers and licensing staff members are leaders in the field of university-based technology transfer. They are familiar with the intricacies of patenting, have worked with researchers in relevant disciplines, understand industries and markets, and have negotiated innovative licensing strategies to meet the individual needs of business clients.