Starting with its 45-nanometer processors next year, IBM will use embedded DRAM (dynamic RAM) instead of SRAM (static RAM) on its processors, effectively tripling the amount of memory it can put on those chips. The company plans to present the results of its research on using embedded DRAM during Wednesday's sessions at the International Solid State Circuits Conference, said Subu Iyer, distinguished engineer and director of 45-nanometer development at IBM.
Modern processors have cache memory integrated directly onto the chip, adjacent to the processing engine. This allows the chip to store frequently used data very close to the CPU (central processing unit), where it can be accessed much faster than data that resides off the chip in the system memory.
For years, chipmakers have used SRAM on processors, but as chips grow smaller, SRAM is having a hard time keeping up, Iyer said. Problems are cropping up with current leakage, and designers would like to use embedded DRAM, which requires fewer transistors and is less leaky.