Rambus thinks it can improve the performance of three-dimensional graphics by adding threading technology to standard graphics memory chips, the company announced Monday.
The addition of microthreading technology to DRAM (dynamic RAM) chips could allow those chips to access small pieces of complex images through multiple paths instead of relying on a single path, said Craig Hampel, director of architecture at Rambus. PC or gaming console graphics could reach new levels of realism with the extra performance generated by this efficiency, he said.
Rambus designs memory and bus interface technologies that are licensed by chip makers.
DRAM chips typically deal with data generated by 3D graphics processors in large chunks, Hampel said. This is because DRAM chips are designed to work with larger amounts of data produced by CPUs (central processing units) like Intel's Pentium 4, he said.
However, gaming software and advanced graphics processors from companies like Nvidia and ATI Technologies render complex images by breaking them down into many small pieces known as triangles. Those triangles are growing ever smaller as game developers push the limits of current technology to develop the next generation of realistic images.
A GDDR (graphics double data rate) DRAM chip must use all the bandwidth provided by the chip to transfer a very small triangle before it can go back and access a different type of triangle. Rambus' microthreading technology allows the DRAM chips to provide different types of small triangles over four separate threads to the graphics controller. This improves the efficiency of the memory chip, since it can provide four different streams of data over the smaller threads in one operation of the chip, rather than having to wait for the DRAM chip to make one large transfer after another, Hampel said. It also reduces power consumption.
This isn't a new idea. CPU companies have been developing chips capable of processing multiple threads for several years. But this approach will be useful for improving graphics performance in new designs, said Jon Peddie, president of Jon Peddie Research.
Rambus hopes to license its microthreading architecture to memory companies and graphics processor vendors, but hasn't signed any partners yet, Hampel said. The company has patented some aspects of the technology and is waiting for final approval of other patents, he said. Rambus doesn't expect the technology to appear in DRAM chips for at least a couple of years.
In order to take advantage of the microthreading architecture, both the graphics chip and memory chips within a system must be tweaked to support this technology, Hampel said. However, the architecture is compatible with existing graphics hardware and software, he said.
Memory chips with this technology could be used in the Playstation 3 gaming console developed by Sony Computer Entertainment, Peddie said. Rambus has already acknowledged its participation in developing memory interfaces for the Cell processor, a joint project of Sony, IBM, and Toshiba, which is expected to be used in the Playstation console