[ Thanks to Kelly
McNeill for this link. ]
“Early this year Transmeta presented a new microprocessor named
Crusoe which achieves superior performance with lower power
consumption, a feature very important for mobile computing devices.
Crusoe was designed for low power consumption. Yet Crosoe uses
conventional CMOS technology and is fully x86 compatible. So where
do the power savings come from? The processor does not follow the
mainstream approach of adding as many features on the hardware as
possible. Instead an alternative design methodology is
employed.”
“This methodology is predominant in the design of network
protocols like the Transmission Control Protocol (TCP) and Secure
Sockets Layer (SSL). Moreover, the RISC architecture and active
networks are also examples of this design methodology, which is
based on the end-to-end argument. Although not an absolute law, the
end-to-end argument can lead to better system designs. Simply
stated, the argument suggests that functions placed at the low
levels of a system may be redundant or of little value when
compared with the cost of providing them at that low level….”
“The end-to-end argument applies in general in system
design. As mentioned in the beginning, Crusoe uses a different
system design. Crusoe is implemented as a combination of hardware
and software. The hardware is rather limited to the basic
functions, while a software layer completely encapsulates it,
offering a completely different set of functions than the ones
inherently supported by the hardware. This allows for a significant
reduction in power consuming transistors on the actual chip. The
software layer, called Code Morphing Software, implements all the
needed x86 functionality and provides an interface to the layers
above it, i.e. the operating system, BIOS, and user applications.
Under this design, highly tuned functions, which most of the time
are not really used, are not hardwired in the chip. Instead they
are implemented at a higher level.”