Transmeta Unveils 256-bit Microprocessor Plans

nam37 writes "PCWorld has an article about how Transmeta has outlined its initial plans for a new 256-bit microprocessor dubed the TM8000. They claim it will offer significant advantages over their current TM5x00 line of chips. The processor will be a switch to a 256-bit VLIW (very long instruction word), allowing twice as many instructions in one clock cycle and greater energy efficiency." The article also touches on the popularity Transmeta enjoys in Japan, noting that 92% (CD: corrected from 55%) of the company's revenue comes from there.

Comments

How will this chip be energy efficient?

[JebusIsLord]

Could someone please explain to me how you can make an energy efficient comparitively simple chip with 256-bit data paths? I thought increasing the bits made chips much more complex, which kind of goes against exactly what Transmeta has been all about up until now. Please explain to me as I assume they know what they are doing.

32-bits, 64-bits, 256-bits .... what's the limit ?

[Taco Cowboy]

First there was that 4-bit microprocessor, then it went to 8-bit, then 16-bit, 32-bit, and 64-bit.

When Transmeta announced it's 256-bit microprocessor, I'm not surprise.

However, I do have a question ....

Is there a theoretical limit on the maximum
bit-path for microprocessors ?

Or in other words, will we see microprocessors with giga-bit (or even exa-bit) path ?

I don't get it!

[Dr. Spork]

It looks to me like Transmeta chips are on absolutely tiny dies and use very little energy. For all those compromises, the performance seems acceptable. Now, I'm not a chip designer, and that may be reflected in my next comment... but I'm asking myself why don't they just stick more transistors onto the die, and maybe more cache? I mean, if a Crusoe were scaled up to the die size/power consumption of a P4 or an Athlon, it seems to me it would kick their asses, even with the code-morphing handicap.

Now I know it's more complicated than just adding more transistors. Still, though, they seem to have a good design, and it seems to me like they should just add more horsepower to each part of the chip. It would have the potential to be a great server chip, and if my wildest dreams came true, it would outperform the Motorolla's best chips by such a margin that Apple would pay Linus to write a code-morphing routine to have the chip emulate a PowerPC. It would be a seamless transition for Mac users, and it would make Macs competitive again for price-conscious performance users.

Re:It's not a 256b datapath, but a 256b VLIW word.

[bentini]

A) Because Transmeta is VLIW, they don't speculatively execute. That's the whole point, Instruction Fetch/Decode (two of the bottlenecks in traditional architectures) have been more or less eradicated because it's so simple. So, really, that point is completely not true. At the moment, my lab group has a chip whose instruction size is about 5-600 bits (I can never remember). Impressive, until you realize that it isn't.

B) The translation doesn't have to be that great. They're still performing fairly competitively with Intel chips.

C) Pentiums don't play well enough. Transmeta can simulate fairly well a several hundred megahertz (probably about 4-500) Pentium III. Also, Intel is notoriously bad at doing such things. Their memory is not written down on how to make such chips, but only remembered in the minds of the workers. It would be VERY hard for them to do that, actually.

D) Transmeta based solutions have often employed other cool ideas in terms of power consumption: Better LCD's that don't need backlights, e.g. Not perfect, but getting there.

E) Transmeta's solution is so amazing that, even if it hasn't revolutionized the world, it has changed the course of Intel's strategy non-trivially. Plus, it's awesomely cool.