[SunRescue] Misc. Questions about my Ultra 10

[Christopher Byrne]

James Lockwood Sent: Monday, December 04, 2000 20:09

>2D performance on the Creator/Elite is, to put it simply, staggeringly
>better for operations _which take a significant amount of time_.  I've
>measured bitblitting at over 7x the speed of a PGX in an AXi/Elite3D setup
>(120MHz UPA).

Which is pretty impressive as a relative measure, but the PGX isnt really a
very good video card to compare against. I mean it wasnt even a good video
card for PC's(AT Rage IIc) never mind professional workstations. I
understand that Sun went this route with their entry level video to keep the
costs down, but couldnt thye have chosen a better chipest, or some more
video RAM?

>Where X falls flat is when there are many small display operations which
>cannot effectively be batched.  The modular design of X increases latency
>for any individual drawing call if the results must be synchronous or
>near-synchronous (such as window drawing/moving).

As I was saying, an inherent limitation of the X-Windows architecture is the
problem here, and it takes a lot of work to get around that limitation. X is
very good at sending displays over the network, as you say in batch mode.
It's far ess adept at providing a very high refresh display (not video
refresh rate, screen refresh) for lots of small transactions, which is what
typical desktop users do.

>Sun's X server supports the acceleration features of their high end
>framebuffers very well, there wouldn't be much point to designing them in
>otherwise.

Yes, for certain features, like the large video transactions you mentioned
above it may be well optimized, but for general every day windows use, i.e.
dragging windows around, opening and closing large numbers of windows etc...
X in general is poor, and significant work has to be done to it to make it
less poor. SGI has done that work, whereas Sun has concetrated on improving
things like CAD, and 3D Rendering etc... Admitedly those are arguably more
important to optimize, I'm just impressed by the quality of a typical users
X windows experience rates on an SGI vs' a Sun

>The Sun OpenGL implementation, running on an Elite3D system, is nothing
>short of astonishing for operations which do not involve texturing.  An
>AXi/360MHz/Elite3D can keep even with an Onyx/IR for geometry and lighting
>bound applications at a tiny fraction of the price.  The Elite3D is
>designed to do shaded CAD very well, and I'd say it succeeds admirably.

Well I'll admit I haven't seen much of the Elite 3D's capabilities, I'd be
surprised if it matched the Onyx as well as you say. I mean these are the
guys who invented OpenGL. I guess if you take out texturing then it's
possible. The biggest limitation on texturing is memory (both quantity and
bandwidth) and SGI's video architecture is better than most at that.
That being said I'll definitley concede to you on the price factor. I called
my SGI rep today to inqure about upgrading my O2-R10K to a new R12K 400, and
the price is something like $4500 just for the processor. I can buy a brand
new fully loaded U10 with Elite 3D M3 for that. I shudder to think about the
cost of a brand new Onyx fully loaded. Last time I looked it was something
like 40 grand, vs. an Ultra 60 at 15k


Chris Byrne