Network problem 98se on 2003 Std.ed. server

Hi!
I have a problem with slow network performance. Clients
are win98se(20 clients) on network with 2003 server. 3
clients are 2000 prof. and they have no problems at all.
Transfer speed from server to clients 98se is aprox. 1.5-3
Mbps and to 2000 prof. from 8-9 Mbps!? Network hardware is
tested, I installed new NIC-s to clients, but speed is
still very low. Server is new, IBM xSeries 235. 2.66 Xeon,
1 GB ddr, NIC BroadCom NetExtreme Gigabit. Network is on
Switch(Planet) with gigabit module. Everything work fine
on old server on wich was OS NT 4.0. Does anyone have a
solution?

"Premanga" <(E-Mail Removed)> wrote in message
news:0b8c01c3a14e$392b35c0$(E-Mail Removed)...
> Hi!
> I have a problem with slow network performance. Clients
> are win98se(20 clients) on network with 2003 server. 3
> clients are 2000 prof. and they have no problems at all.
> Transfer speed from server to clients 98se is aprox. 1.5-3
> Mbps and to 2000 prof. from 8-9 Mbps!? Network hardware is
> tested, I installed new NIC-s to clients, but speed is
> still very low. Server is new, IBM xSeries 235. 2.66 Xeon,
> 1 GB ddr, NIC BroadCom NetExtreme Gigabit. Network is on
> Switch(Planet) with gigabit module. Everything work fine
> on old server on wich was OS NT 4.0. Does anyone have a
> solution?

If you plug directly into the switch you have the Server attached to what is
the throughput.
You've then split the problem in two halves Server and/or MDF switch and
other LAN design.
My guess would be from what you've stated that the server is the problem.
You don't mention what OS your currently running on it or whether the server
is the default hardware/software configuration or has been upgraded or
tweaked to any extent.
Personally it sounds as if your upgrading a network that is running on a
kaleidoscope of vendor products which may or may not be compatible or
compliant with fast ethernet standards.
Altering RWIN on the 98SE clients might help.

Ok, here are the specs.
Server-IBm xSeries 235, original hardware, untweaked,
specs from previous post. OS is Win 2003 Std. Ed,
configured as file server with shared folders in wich are
files and application for clients, etc. Workstations are
Pentium 1 and 2 with OS Win 98SE(20 clients) and 3 clients
P4 with OS Win 2000 Prof.
Lan- Planet Switch 24 port + Gigabit module.
Difference from previous work surrounding where everything
work well(and overall slow but faster then with new
server) is that old server was with OS NT 4.0.
Nothing except server( and OS, ofcourse) didn't changed.
Before new server I didn't bother to much for speed in
network because buying new server was last solution, I
changed old hubs for switch, old NIC-s for new ones(Planet
ENW-9503/4), network overall was tested and have category
5 certified.

Once again, main point is that when Win 2003 arrived in
network environment, the problems start ONLY on win 98
workstations. The difference in network speed is great,
transfer of 10 MB on win2000 is from 1-2sec and on win98
is from 7-12 sec. That wasn't so on previous server
environment.