[comp.sys.sgi] Questions about the Personal IRIS

XBR2D96D@DDATHD21.BITNET (Knobi der Rechnerschrat) (12/26/88)

Hello,


  I've got three short questions about the Personal IRIS:


1) Is it possible to field-extend the cache sizes of that
   machine. If the answer is yes, how much is it?

2) During excessive use of a Network-Test-Program called 'dog'
   (listening Reinhard ????), we discovered that people inside
   the Personal IRIS side of the pipe were really handicaped compared
   to a 4D/70G. This brought us to the conclusion that the Personal-
   Iris Ethernet adapter is slower that the adapters for the G and GT.
   Is this observation correct?

3) It seems that the GL function 'getmcolor' does not work if you
   are in OVERDRAW-mode on the Personal IRIS. On a G/GT/GTX that
   function works perfect in OVERDRAW mode. If this is a known
   bug, sorry for asking. If it's unknown, please inform the people
   in charge.

Questions 2+3 were rised on a fully equipped 4D/20 with software
release 3.13809261636.

Regards and my best wishes for a happy
new year 1989

Martin Knoblauch

TH-Darmstadt
Physical Chemistry 1
Petersenstrasse 20
D-6100 Darmstadt
West-Germany

BITNET: <XBR2D96D@DDATHD21>

vjs@rhyolite.SGI.COM (Vernon Schryver) (12/28/88)

In article <8812260910.aa25159@SMOKE.BRL.MIL>, XBR2D96D@DDATHD21.BITNET (Knobi der Rechnerschrat) writes:
> 2) During excessive use of a Network-Test-Program called 'dog'
>    (listening Reinhard ????), we discovered that people inside
>    the Personal IRIS side of the pipe were really handicaped compared
>    to a 4D/70G. This brought us to the conclusion that the Personal-
>    Iris Ethernet adapter is slower that the adapters for the G and GT.
>    Is this observation correct?
> 
> Martin Knoblauch
> West-Germany
> BITNET: <XBR2D96D@DDATHD21>

The UDP/IP/ethernet in the 4D20 is the fastest we currently ship.  It
speaks directly to memory, rather than making the CPU stroke it over the
VME or other bus.  Perhaps one of the graphics or CPU-&-cache-hardware
experts could say if the performance difference is there.  Doesn't dog do a
lot of floating point?  Does your 4D20 have a floating point chip?

You might want to measure relative performance using the other interactive
network stress test, 'arena'.  In all of this, be careful.  You should have
seen what arena did to old minicomputers manufactured by a large eastern
company when arena ran unthrottled, at > 50 pkts/sec/machine.

Vernon Schryver
Silicon Graphics
vjs@sgi.com