Fast memory to boost PC speeds
Personal computer performance is expected to speed up dramatically when memory technology from Rambus is introduced in 1999.
The Direct Rambus high-speed memory interface, which is being supported by the main DRAM (dynamic random access memory) manufacturers and Intel, promises to improve overall system performance by speeding up the rate data travels from memory to the processor, a critical data path in all personal computers and a performance bottleneck which has plagued PCs since their inception.
Simply put, microprocessor speeds are increasing much faster than memory speeds. To function, microprocessors reach into main memory for data, which the processor then manipulates. Because of the speed disparity, processors cannot get the data they need fast enough from system memory. Processor designers have created additional high-speed memory caches to keep data-hungry processors occupied, but this is really only a Band-Aid since significant bottlenecks remain.
The technology was outlined this week at Microprocessor Forum.
The Direct Rambus interface is intended to open the data floodgates much further. The interface doubles the memory bus width and increases the data transfer rates to 1.6GB/sec; memory bus frequency shoots up to 800 MHz. Currently PCs communicate with memory at 66 MHz. Overall, memory performance is expected to improve about ten-fold.
The technology will be incorporated on memory chips as well as processor chipsets and other components to ensure a smooth flow of data, pointed out George Iwanyc, an analyst at Dataquest.
"It will improve overall system performance," he said. Eventually, Direct RDRAM, or Direct Rambus DRAM, will replace SDRAM, or Synchronous DRAM, which is the current high-end memory for PCs.
While Rambus is not alone in this field, it is the technology that is the furthest along, Iwanyc added. Both Double Data Rate DRAM and SL DRAM function in a similar manner. But neither technology is not yet so fully developed as the Rambus technology. These technologies also do not have the same level of support from memory makers, processor vendors, and even computer makers. Samsung, Mitsubishi, and others have already endorsed the Rambus project.
"Most of the DRAM companies have already licensed it," he added.
Rambus also claims that the interface has been built to avoid obsolescence. The interface will work with memory densities ranging from 32MB to 1GB. Most PCs today use memories with densities of 16MB or less. This gives the technology a lifespan of at least five years, according to the company. Memory using the Rambus interface also fits within the physical and thermal parameters of current high-end SDRAM chips.