The other problem with centralising X is network bandwidth. All of the
graphics have to pass to and fro which means you need both high
bandwidth low latency and no network problems.
True but do the math. We used to run dozens of X terminals on a
10 mbit thick ethernet, (i.e collision city) with no problems.
Now with 100mbit switched...... That's enough data to re-paint a
1 megapixel screen with raw raster data (i.e no compression)
about 10 times a second. We used to figure that dedicated 64Kbit
full duplex was the minimum for a useable X-terminal. With todays
raster filled desktops I'd suggest 1Mbit, or 15 times what we used
to use. That still means 100 desktop's per 100Mbit interface on
the server. Go to www.ltsp.org and read about the Florida city
which has 100 diskless PC's running as X-terminals hanging off two
dual 500mhz servers. Then you can always dual network interface
the server.....You'll run out of grunt running apps on the server
before you run out of network bandwidth for the display.

I'd run the apps locally and servers remotely but with an auto install
tool. Unless you're restricted in the client PC end with old processors.
Ltsp can configure the diskless client to run local apps, one advantage
of this is access to sound and peripherals like floppy - cdrom etc
is like "normal" where as if it is an X-term you need to run esd or
similar and send the sound across the network as well as capture
requests to local devices and re-route them, tricky!

One point in favour of the X-term is that *nix is re-entrant and I
believe that Linux is too (someone correct me if I'm wrong) what this
means is that once an image of staroffice is loaded into RAM on the
server, subsequent users do not have the program loaded again and
again, *nix just allocates a data space and set of pointers
for that user to the already existing exe. This means that second and
subsequent users of star office will not only see a faster startup,
the memory required is not num_users X app_memory_requirement but
significantly less.

HTH

P.







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