IBM says hi to DRAM, tells SRAM to scram

Alex Zaharov-Reutt
Thursday, 15 February 2007 16:27

Opinion and Analysis

Scram, SRAM, you’re being chipped off the block by IBM, to be replaced by eDRAM – embedded dynamic access ram. Why? To speed up your processor while using less power.

Announced at the IEEE’s International Solid State Circuits Conference (ISSCC) in San Francisco was IBM’s breakthrough in getting DRAM onto micrprocessors for faster performance and lower power consumption than SRAM, the on-chip memory technology used by most processors today.

Apparently the new process surprisingly delivers DRAM that is slower than SRAM, but as there is more DRAM that can be packed onto a chip while taking up only one third the space, and using only one fifth the power of SRAM, the overall effect is an increase in performance thanks to the additional amount of RAM that each chip can hold. IBM has talked about doing this for years, but has only now been able to actually do it.

This is important as SRAM memory solutions are quite large, and there’s a problem in trying to get SRAM ever smaller – that of electron leakage. The wires are now getting so small that electrons can pop out and end up in places they were never intended to be. DRAM also suffers from this problem, but not to the same degree as SRAM. Therefore, moving to a DRAM solution solves the problem of electron leakage, at least for the time being, and IBM has figured out how to do this thanks the ‘Silicon-on-Insulator’ (SOI) process which IBM itself invented back in 2001 on processors that were 130nm in size – significantly larger than the 90nm, 65nm processors now in everyday use and now the latest, even smaller, 45nm processors

While the technology is set to appear in 45nm processors from IBM due next year, some pundits claim the technology won’t find its way into the everyday IBM, Intel and AMD processors just yet, and is better suited to technologies requiring simpler processors, such as music and video players and other devices needing an embedded processor.

Either way, it’s another development that ensures Moore’s famous Law remains unbroken, and computing power will continue doubling every 12 to 18 months for the foreseeable future. Thank goodness for that – after all, if there really will be a Windows Vienna successor to Vista in 2010, there’s no doubt we’re going to need all the extra computing power we can get!