How Extreme Is 'Quartz Extreme?
Very, According To Apple - A Performance Report
9-12-02
[ editor's note - a reader pointed out that it was actually
Chris
Bourdon that ran the demo of Quartz Extreme while Phil
Schiller looked on, this fact, unfortunately, did not make
it into long term memory, and we regret the error.]
We attended the Phil
Schiller Keynote at Seybold
Tuesday morning. It was interesting and quite different from
a Jobsonian Keynote. The presentation was very tailored to
the publishing and printing crowd that made up the audience.
It was all about software, software, software, and how Apple
was working hard at tweaking the numerous features of OS X
and the applications that come with it, to make the lives
of those in the audience easier. It was really a nuts and
bolts talk. Nothing flashy, and hardware was barely mentioned
... though there was a series of 5 of Apple's Xserves, stacked
in a rack, on-stage that were helping run the presentation.
Schiller made a passing reference to these.
One thing that Phil spent some time on, and
which was at the top of the presentation, was Quartz
Extreme. For those of you that haven't heard, Quartz Extreme
is Apples name for the way Apple has coded the rendering of
the Quartz
Graphics layer in OS 10.2 to be done largely by the graphics
card. This frees up the processor(s) for other tasks.
Phil's 's presentation of this effect, which
we outline in the picture section below, was pretty impressive.
Using three utilities he was able to turn Quartz Extreme off
and on, and display how that affected processor usage and
the compositing frame rate of the Quartz layer.
Apple's definition of Quartz:
"Everything you see on screen is the result of millions
upon millions of calculations by Quartz, the revolutionary
composited windowing system in Mac OS X that uses the Portable
Document Format (PDF) as the basis of its imaging model.
Quartz delivers crisp graphics, anti-aliased fonts, and
blends 2D, 3D and QuickTime content together with transparency
and drop shadows"
And their definition of Quartz Extreme:
"Quartz [Extreme] uses the integrated OpenGL technology
to convert each window into a texture, then sends it to
the graphics card to render on screen. The graphics processor
focuses on what it does best Ñ graphics Ñ freeing the Power
PC chip to do more operations in the same amount of time.
Everything is zippier"
So this is Apple's story. We will be testing Quartz Extreme
out in-house, when we have a chance, to see how much of a
difference it makes in real work flow.
It is important that you click on the small images below
so that you can see the detail of what is going on.
Phil used an in-house application to disable Quartz
Extreme (you can see it up in the right-hand corner) and
used two other applications to gauge performance. The
round, speedometer like one, measured frames per second
of on-screen graphics. The other guage, CPU Monitor, which
you can find in your Utilities folder, shows processor
usage. Since there are two processors in this machine
(no doubt a Dual 1.25 GHz machine), there is a monitor
graph for each processor.
Here Quartz Extreme has been turned off. A high resolution
QuickTime movie is playing and the Terminal application
is launched and been made semi-transparent. The bottom
graphs in the right hand corner shows between 70-80% processor
usage and Quartz frame rates of about 30 per second (this
shows, as we will see later, that the graphics card is
being very under utilized)
Processors get even more saturated with
data and frame rates drop.
Quartz Extreme has been turned on once
again, off-loading graphics rendering to the graphics
card (probably the NVIDIA
GeForce4 Ti, in the demonstration machine), Becuase
the graphics card is more efficient at processing graphics
data the number of frames per second goes up and bandwidth
usage of the processors drops dramatically.
Here Shiller moved the transparent Terminal window around
showing the continued smooth functioning of the machine
Finally Phil opened up another QuickTime movie and nearly
saturated the graphics card, rendering about 160 frames
per second. Processor usage nearly doubles, but there
is still significant headroom for the machine to manage
additional tasks.
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