gordonl (02/17/83)
A recent article claims that the 68K can emulate floating the floating point sequence: load multiply store faster than the Intel 286 Floating point chip (80287, I think its called) This is, of course, an interesting comparison. First, the comparison is invalid as the particular example is load/store intensive; something a coprocessor will naturally do less well. I'm sure the timings heavily favor the chip in a "real world" example. Further, John Gilmore was comparing the 32-bit floating point on the SUN with an 80-bit IEEE standard floating point chip! Those that have studied the chip know that theres a hell of a lot of work in supporing a IEEE standard floating point unit. There are several kinds of rounding, several kinds of infinity control, etc. I'm sure that the SUN package ignores these things. So long as we're going to compare apples and oranges I'd like to point out that my Heath H8 is faster than the Sun system becase the H8 can compliment a register faster than the 68K can. Its easy for systems software hacks (such as myself) to say "well, who cares about all that crazy floating point stuff?" Unfortunately, an important set of end-users of these machines are people who care very very much. The IEEE FP standard is not that complex because it was "designed by comittee", its that complex because the users of FP need those things. I'm sure we wouldnt like it if a bunch of FP hacks got together and speced out what an OS should look like and laughed at us when we complained... By the way, I thought that SUN was planning on marketing to scientific users. If thats so, they certainly have a wider package than the 32-bit version. Its important to compare the speeds of the "full strength" packages 'cause people who care about FP timings also (usually) care about precision. Can you fill us in, John? gordon letwin microsoft decvax!microsoft!gordonl