eho@bogey.princeton.edu (Eric Y.W. Ho) (06/26/89)
Does anyone at TMC considered building a somewhat scaled-down CM box -- like putting just several hundreds or just a few thousands cells on say a big wafer or several large chips so that it can be hooked to one's desktop (either as a separate box next to the desktop or actually inside the desktop -- that would be really nice) so that people with a limited budget that can take advantage of this architecture (& don't want to learn another entirely new enviornment -- it is nice that CM can adapt easily to the host's environment) but not necessary need so many cells can go out and get one of this box (either for personal use or to be shared by a small group of half a dozen or so people) and start doing some useful things with it. I think that the trick here is partly costs (a CM now need megabucks and at least a machine room to house the box and a small group just won't have the space for it, let alone the megabucks) and partly technical -- i.e. how easily the CM can interface with other desktops (it all boils to a matter of good compromise & good sense I guess -- if you can't have the whole pie then at least get a small part of it). Eric Ho Cognitive Science Lab., Princeton University email = eho@bogey.princeton.edu -- regards. -eric-
landman@Sun.COM (Howard A. Landman) (06/29/89)
In article <5847@hubcap.clemson.edu> eho@bogey.princeton.edu (Eric Y.W. Ho) writes: >Does anyone at TMC considered building a somewhat scaled-down CM box -- like >putting just several hundreds or just a few thousands cells on say a big wafer >or several large chips so that it can be hooked to one's desktop (either as a >separate box next to the desktop or actually inside the desktop -- that would >be really nice) so that people with a limited budget that can take advantage >of this architecture (& don't want to learn another entirely new enviornment >-- it is nice that CM can adapt easily to the host's environment) but not >necessary need so many cells can go out and get one of this box (either for >personal use or to be shared by a small group of half a dozen or so people) >and start doing some useful things with it. Whew! That's an awfully long sentence! Anyway, I brought this same issue up a few months ago. Here's one problem: the cost of a CM can be divided into 4 parts. (1) Host (2) Host interface board (3) Sequencer (4) "Cells", to use Eric's term. The host has to be sufficiently powerful to not be the bottleneck; a small Sun 4 or a VAX 8600 might be O.K. Both CPU power and I/O capacity are important. Either way you're talking at least $10K to $X00K. The interface board and sequencer are the biggest cost problem - they cost the same for one processor or 16K. Let's say another $10K to $100K. Finally there are the processor cells. A good number might be 256. But each CM processor is fairly weak (maybe 0.1 MIP) by itself - it's only in large numbers that they start becoming powerful. A 256 processor CM would have a peak, maximally utilized power of about 25 MIPS. Not very exciting for a couple hundred $K. If you really want to play with what it's like to program a CM, it would probably be better to just write StarLisp and Fortran 8X and C* compilers for conventional machines, and buy a fast deskside to run them on. Howard A. Landman landman@sun.com