Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!bloom-beacon!EXPO.LCS.MIT.EDU!keith
From: keith@EXPO.LCS.MIT.EDU (Keith Packard)
Newsgroups: comp.windows.x
Subject: Re: X11R4 server on DS3100; pro/con
Message-ID: <9001041944.AA03635@xenon.lcs.mit.edu>
Date: 4 Jan 90 19:44:25 GMT
References: <1103@ursa-major.SPDCC.COM>
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
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In color, there are a very few operations for which the DEC product server is
substantially faster than the MIT server; the two I can remember offhand are
transparent stipples (including polytext) and zero-width lines. In most
instances the MIT server equals or surpasses the performance of the current DEC
product.  Furthermore, the MIT server will use much less memory than the DEC
product.

This is certainly *not* because the engineering effort at DEC was inferior to
the effort done at MIT, in fact DEC helped substantially in the release by
donating many of the improvements which are in R4.  The very short schedule
that produced the DS3100 was rather tough on server optimization efforts, we at
MIT benifited from the work that was done by them and were able to focus
additional effort on some critical graphics operations (besides; DEC didn't
have any competition to spur development like I did...)

In monochrome, the choice is much easier; DEC spent little time optimizing
monochrome before releasing the PMAX, for R4 I've spent a bit of time speeding
up some common monochrome operations (text in particular) which make the MIT
server a clear performance winner.

The MIT server also has support for several new extensions which many MIT
clients can use (SHAPE in particular).  I don't expect to see those in
a DEC product for several more generations.

If you're not just out for the fastest server, but also consider things like
support, testing, documentation, etc., you'll want to look more closely at the
DEC products.  They provide a good level of performance (the best that I know
of) for a production piece of code.

Keith Packard
MIT X Consortium