[rescue] Sun 711

[James Lockwood]

On Wed, 1 May 2002, David Passmore wrote:

> Because, frankly, this is a 'dumb' task. If all you're doing is taking
> images from a disk and throwing them into a framebuffer, then you need to
> throw bus and clock speeds at it and this is what Intel excels at. The cost
> of graphics hardware for a high-end solution is a waste of money-- for this
> particular application. You could put together a machine to do this with a
> trip to Fry's.

I beg to differ.  Intel exceeds at clock speeds and integer perf, that's
true, but I/O bandwidth has historically been bad once you start requiring
more than what is "mainstream".

For an app like this you need to sustain 300MB/s both to your disks and to
your framebuffer.  The number of "off the shelf" PCs that can do this is
quite small.  I can think of a number of "server class" PCs that can
manage it, but they're all are fairly expensive and highly unlikely to be
found at a place like Fry's.  I agree with the earlier assessment that a
single 64-bit/66MHz bus would be inadequate.

100MB/s is easy.  300MB/s is not.  300MB/s both to disk and video is
really not.  You not only need big I/O cajones, but you are stressing main
RAM bandwidth in a significant way.  Fast CPU cache will do nothing for
you here.  Interrupts will kill you if you're not careful.

-James