Rambus Boosts Direct RDRAM Clock to 600MHz
Rambus Inc of the US has increased the clock frequency of its direct rambus dynamic random
access memory (direct RDRAM) to 600MHz. The firm announced a 577MHz design in July 2000,
and commented at the time that it would be difficult to boost speed any further. If the new 600MHz
design is commercialized, the data transfer rate will be 1.5 times faster than the current 400MHz
chips, achieving per-lead rates of 1.2 Gbits/s, or 2.4 Gbytes/s on a 16-bit bus. Commercialization is
slated for about 2005.
Over 600MHz, the low-loss approximation of the direct RDRAM transmission path collapses, and
the signal begins to attenuate sharply. As the new clock is a little under this threshold, almost no
changes would be needed to printed circuit boards (PCB), although minor design modifications
would be needed in the DRAM and controller interfaces. Rambus has not yet disclosed details, but
explains that the change was made possible by "assuring the operating margin, including the timing
margin."
The firm has said that 600MHz is the ceiling until new technology is introduced. One candidate is the
Quad Rambus Signal Level (QRSL) multi-value technology, already developed by Rambus.
(August 2001 Issue, Nikkei Electronics Asia)
--------------------------------------------------------------------------------
Copyright (c) 1996-2001 Nikkei Business Publications, Inc. All Rights Reserved. |
