Re: XVGA over UDP


"Mac" <foo@xxxxxxx> wrote in message
news:pan.2006.04.05.05.40.08.329213@xxxxxxxxxx
On Tue, 04 Apr 2006 09:30:43 +0200, Deefoo wrote:


"Mac" <foo@xxxxxxx> wrote in message
news:pan.2006.04.04.06.11.49.748864@xxxxxxxxxx
On Mon, 03 Apr 2006 20:20:49 -0400, Phil Hobbs wrote:

[snip]


I have a very nice Ethernet-based daisychained KVM system for my
Opteron
cluster. (It's made by, gasp, IBM.)

There's a box that sits behind the power bar on the rack, which has 4
Ethernet ports, each of which can have 6 servers daisy-chained on it.
Nice
neat cabling, and it works over > 100 ft of cable if you want it to,
and
works up to 1600 x 1280 or perhaps higher.

Cheers,

Phil Hobbs

Are you sure it is Ethernet based?

To get 1600 x 1200 (probably not 1280) you need:

1600 x 1200 x 24 bits x 70 fps = 3,225,600,000 bits per second.

Yes, it could be compressed, and it could be less than 70 fps, but
even so, you are talking about a lot of digital BW. Even gigabit might
not be up to it for 1600 x 1200.

--Mac


UDP is the OP's input, he doesn't have to worry about data rates, he
just
has to display what's coming in. It's like a graphics card with an
Ethernet
bus instead of a PCI (Express) or whatever.


The OP said UPD, not UDP. He may have meant UDP (as John Larkin
suggested), and he may have meant UTP. Who knows?

In any event, the PCI bus can handle 33 MHz x 32 bit = 1,056,000,000 bits
per second. Of course, there is overhead, so that is a bit optimistic.

Fast Ethernet is 100 megabits per second. Not even close. So it has to be
gigabit Ethernet. But by today's standards, even gigabit isn't nearly fast
enough for a video bus. In fact, it hasn't been for some time. Just try to
find a high-end 32 bit 33MHz PCI video card.

Put a processor + Ethernet driver in the FPGA to handle the UDP/IP
stack,
add an Ethernet chip and some memory for firmware and image buffer and
use
what's left of the FPGA to get the data on the display. Make it GCC
compatible and most of the programming is done. See www.opencores.org
for
more info. Any cheaper won't be easy since most of it is already for
free.


I don't think you know what you are talking about. There would be no
reason for a processor. Just an FPGA. And what do you mean by GCC
compatible?

I didn't notice the OP wrote UPD (he did write UDP in the subject) but
supposing UDP he will need some kind of processing to get the IP stuff done.
So put a processor IP in the FPGA for which a GCC cross compiler exist and
use all the open source network stuff to get the job done. See what I mean?
But if the OP means UPD I don't know what he is talking about.


And why bother with all of this anyway? Just use X or remote desktop or
whatever. Remote display over IP is a solved problem if the remote
location is also a PC.

Why bother is not my problem.

<snip>

--DF


.

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