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Core Duo - Intel's Best CPU?
Bender writes "How good is Intel's Core Duo mobile processor? Good enough that Apple chose to put it in the iMac, and good enough that Intel chose to base its next generation microprocessor architecture on it. But is it already Intel's best CPU? The Tech Report has managed to snag a micro-ATX motherboard for this processor and compared the Core Duo directly to a range of mobile and desktop CPUs from AMD and Intel, including the Athlon 64 X2 and the Pentium Extreme Edition. The results are surprising. Not only is the Core Duo's performance per watt better than the rest, but they conclude that its 'outright performance is easily superior to Intel's supposed flagship desktop processor, the Pentium Extreme Edition 965.'"
The reason for going to 64-bits is to increase the amount of physical address space, not for speed. The majority of applications, especially integer, do not benefit from bigger registers and wider ALUs.
At the time it was introduced, there was no other microprocessor that came close to matching it.
It was indisputably not only the best microprocessor Intel had produced to date, but the best microprocessor on the market.
Simply no contest. No argument. It superlative in every way, the fastest, the cheapest, the lowest in power consumption, the most advanced in architecture, the widest path. It was king of the hill, the top of the tree, the Cadillac of microprocessors, the ne plus ultra, it bestrode the world of microprocessors like a colossus.
The world will never again see the day when one manufacturer so dominated the microprocessor market that a single product had a 100.0% market share.
"How to Do Nothing," kids activities, back in print!
Actually, x86-64 does have some speed benefits over standard ia32 for smaller programs and data sets in that it doubles the number of exposed registers. Most other archs were not register starved on the 32 bit version, so going 64 bit generally slowed the system down a bit because the pointer size doubled, taking more memory bandwidth to store pointers.
Yeah, they use both HDL coding and EDA (cad-like) tools to design most microprocessors. The designs are too massive to design them by placing each wire manually - they haven't done that for _several_ generations (1980s? - not sure really)
That's not to say there isn't a small army of design engineers at Intel and AMD who work with nothing but schematics - there are. Its just that most of the logic design work is done on the HDL coding level (with either VHDL, IHDL, Verilog, or some other tool). You only start dealing with schematics at a much later stage of development. Until then your designs are constantly changing and its infinitely easy/faster to change a few lines of HDL code than to re-write hundreds/thousands of wires and transistors.
I've worked at both Intel and AMD in the past and in both cases you could take the entire codebase for a processor (HDL, microcode, ROM, etc), compile it with the right HDL compiler and run the entire thing with small test programs as a simulator. Thats how much of the validation/verification work is done before they make the masks.
As for using the old code bases... That's done a lot. There's just too much complexity and too little time for them to re-write every processor from scratch. You also have countless hours invested in making sure previous designs work. If you're only doing small changes it would be hard to justfy building something from scratch since you'll have to do all of that validation work again.