Ed McNierney ed at TOPOZONE.COM
Mon Feb 14 21:18:28 EST 2005

Norman -

Having (formerly) been in the business of building accelerated graphics
hardware for a while, I'll respectfully disagree unless you've got some
test data.  You're presuming that, for small patterned vectors, a
graphics processor can "blow the doors off" a general-purpose processor,
and that's really not likely to be the case.  These operations are quite
simple, and the limiting factor tends to be memory bandwidth, rather
than the drawing capabilities of the processor.  Preloading the pattern
is trivial - it's manipulating the RAM that's the bulk of the work.

3D graphics rendering requires quite a bit of math, and the construction
and acceleration of rendering pipelines is a BIG improvement.  But 2D
line drawing, pattern filling and the like primarily consists of loading
patterns and stamping them out into RAM, and most CPUs manage RAM
read/modify/write cycles just fine.

In fact, many of the recent major improvements in graphics hardware have
focused more on improving the card's access to memory than on anything

        - Ed

-----Original Message-----
From: UMN MapServer Developers List [mailto:MAPSERVER-DEV at LISTS.UMN.EDU]
On Behalf Of Norman Vine
Sent: Monday, February 14, 2005 6:41 PM
Subject: Re: [UMN_MAPSERVER-DEV] wishlists

Ed McNierney writes:
> >
> If you're asking a
> graphics accelerator to help you draw a fancy-looking 30-pixel-long
> styled railroad symbol, it's unlikely to be much help.

If you have to start from scratch everytime this is true.

However on a dedicated server there is no reason to not have
preloaded the instructions for drawing your commonly used GFX
objects :-)

Also modern GFX cards blow the doors off of the CPUs when it comes
to pusing 'bits and bytes' arround even when in 2D mode.



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