On Mon, Jan 19, 2009 at 09:03:23PM -0800, Karen Shaeffer wrote: > On Mon, Jan 19, 2009 at 05:18:19PM -0500, Joe Landman wrote: > > > > > These days, perception == reality :( > > Actually, Jeane Kirkpatrick coined the phrase, "Perception is more > important than reality." But then that can only be held true in > a contrived environment, because, in the end, "Reality isn't optional". > > As for GaAs, it is not suitable for large scale integration or low > power, both essential requisites to displace Si. >
One item to add to this discussion is the fan out of ECL logic which is so much wider than TTL logic. ECL can be built with both silicon and with GaAs transistors. In one discussion I think ECL/GaAs was compared to Silicon CMOS. With the vast transistor counts of modern CMOS processors and high speed on chip switching speed there is less need for high device to device fan out of ECL logic. Silicon CMOS logic has a power advantage... GaAs in some cases has a three fold speed advantage. http://books.google.com/books?id=QHtalNXHKbsC&pg=PA450&lpg=PA450&dq=GaAs+versus+Silicon+switching+speed&source=web&ots=G0Ysy1kiAw&sig=QQBFInUFAOj5UKOjhqjn--GWQyM&hl=en&sa=X&oi=book_result&resnum=10&ct=result Once the door to exotics is open, diamond may be interesting. http://www.theinquirer.net/inquirer/news/396/1044396/diamond-transistor-clocks http://www.nanotech-now.com/news.cgi?story_id=27984 The thermal properties of diamond are compelling... S. Cray used GaAs and some interesting interconnect and cooling tricks on the CrayIII project if I recall. The transistor counts on Si CMOS have effectively erased any potential advantages of ECL on practical systems. -- Regards, T o m M i t c h e l l _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
