rsimonian@nasamail.nasa.gov ("RICHARD P. SIMONIAN") (02/28/90)
Does anyone have statistics on how the RE2 chip affects performance on the Personal Iris? I'm particularly interested in X-windows performance. Rick Simonian Harris Space Systems Corp. rsimonian@nasamail.nasa.gov or... rsimonian%nasamail@ames.arc.nasa.gov
jsw@xhead.esd.sgi.com (Jeff Weinstein) (03/02/90)
Getting an RE2 is the best thing you can do to help your X performance on a Personal Iris. The RE2 has several advantages over the RE1: 1) Does logicop in hardware. That means that when you specify XOR we don't have to read the bits back, twiddle them on the host, then write them back to the graphics board. 2) Writing 8 bit deep images is much faster since the RE2 can unpack 4 pixels from a single 32bit words, whereas the RE1 had to have one pixel per word, no matter what. 3) The RE2 is faster than the RE1. You may not see a huge speedup with the RE2 with today's X server, but in the future we will be taking advantage of the RE2 in a much bigger way. If you are serious about running X you probably want an RE2. To find out which RE chip you have run the 'hinv' program. If if says 'Graphics Board: GR1.1' then you have an RE1, GR1.2 is an RE2. Jeff Weinstein - X Protocol Police Silicon Graphics, Inc., Entry Systems Division, Window Systems jsw@xhead.esd.sgi.com Any opinions expressed above are mine, not sgi's.