1.6 GHz Alpha With Transputer Features Coming?

GFD writes "The Register has a story about a 1.6ghz alpha with 8 paralell rambus channels (8oomhz) and a transputer like channel to 4 other cpus (10ghz), integrated memory controller and l2 cache. Science fiction? Maybe, but oh my God what specs!!"

Comments

Details of transputer architecture

[Morgaine]

Transputers had at least 3 features that made them so far ahead of their time that they died through lack of applications. Or maybe it was just because the Brits and the French are lousy at bringing things to market. If only Intel had bought out Inmos ...

Anyway, getting back to the features:

- A process scheduler implemented in hardware (an outer loop outside the usual inner instruction fetch and execute loop), which allowed transputers to implement concurrency with very fine granularity because the context switch time was exceptionally low. (And the process scheduler was directly driven by I/O events at the transputer links, below.)

- Four high-speed serial "Inmos links" on-chip through which the transputer could be linked directly to other transputers and to other peripherals without further glue logic, so that building multiprocessors was very inexpensive and scaled linearly. Furthermore, these links ran not only extremely quickly (for their time) despite being serial, but more importantly they ran under DMA power all simultaneously and at the same time as the processor was doing its own thing independently.

- The above two features made the transputer exceptional for multiprocessing, but I think its instruction set was also far, far ahead of its time: not only ultra-RISC, but highly extensible too. For example, numeric literals in instructions were only as long as needed, because an extension bit would (if present) indicate that more bits were to follow if needed. This made code *extremely* tight. The scheme also allowed extensions to the instruction set to be made in a fully backward-compatible manner.

The transputer was ultra-cool, and the world hasn't seen anything like it since. No doubt somebody will reinvent this approach some day, but probably in a US or Japanese lab, as usual, and they'll take the credit for exceptional design ideas made in an earlier age. Sigh.