Gigabit very slow - w2k3 server and w2k pro

I have a gigabit network setup between a Windows 2003 Server machine and a W2k Pro machine. Unfortunately performance is mostly very poor, with an occasional blip of adaquate performance. After working on the issue for a while, I am at a loss and would appreciate any suggestions.

Details:
Computer 1
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Dell 1600SC Server running Windows Small Business Server 2003. 2GB RAM (1.7GB available), SCSI disk subsystem, Intel Pro/1000 MT ethernet adapter.

Computer 2
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IBM eServer Xseries 205 running Windows 2000 Professional. 512MB RAM (400+MB available), SCSI disk subsystem, Broadcom NetXtreme Gigabit ethernet adapter.

Performance numbers:
From the Comp 1 to Comp 2, I can get around 7-8MB sustained transfer. From Comp 2 to Comp 1, I get significantly worse, around 2-3MB/sec with an occasional blip up to around 26MB/sec (sustained for perhaps 3-4 seconds total).

I have tried both computers hooked through a DLink 8port gigabit switch and hooked direct to each other.

During the transfer, cpu usage is very low on both systems (under 10% utilization), RAM is available (400MB on comp 2, 1.7GB on comp 1) and nothing appears in the event viewer to make me think there is an issue.

From the W2K3 server, I can transfer to other systems at a sustained 25MB-30MB/sec which is where I'd like to get for the connection between these two systems.

I did try some hard drive tests and the drives can easily sustain over 30MB/sec read/write so I do not believe any of the 3 major bottlenecks (cpu, memory, i/o) are an issue.

Any ideas on what it might be or what I can try would be greatly appreciated.

 

What kind of performance do you get when the Win2K Comp2 is talking to other machines? Is this also slow or is the problem unique to the Comp1 - Comp2 scenario described here?

DRD

 

I believe the issue is with the Win2k machine .. I didn't do any extensive testing but I did try copying to/from a WinXP Home machine and had similar transfer rates. The file I was transfering was around 825MB.

Is there TCP tunable options in w2k? This machine was provided with a machine it operates -- perhaps it was misconfigured from the factory?

 

Updated.. benchmarks..

I did some benchmarks on the systems.. TCP/IP transfers look good, Netbios doesn't look so hot.. any ideas on what might be causing this drop in performance?


NETIO - Network Throughput Benchmark, Version 1.14
(C) 1997-2001 Kai Uwe Rommel

TCP/IP connection established.
Packet size 1 KByte: 30362 KByte/s
Packet size 2 KByte: 33965 KByte/s
Packet size 4 KByte: 36740 KByte/s
Packet size 8 KByte: 39213 KByte/s
Packet size 16 KByte: 57554 KByte/s
Packet size 32 KByte: 62979 KByte/s

NetBIOS connection established.
Packet size 1 KByte: 5129 Byte/s
Packet size 2 KByte: 7959 KByte/s
Packet size 4 KByte: 8488 KByte/s
Packet size 8 KByte: 157 KByte/s
Packet size 16 KByte: 24276 KByte/s
Packet size 32 KByte: 28196 KByte/s

As you can clearly see, at the best, NetBIOS is 1/2 the speed of a TCP/IP connection.. at worse, we are looking at 5k/sec on a gigabit connection. OUCH! During a regular file transfer, it seems to stay around 6-8MB/sec (2-4KByte packets default?)

 

I have an almost identical thread/problem with my Gigabit network. Only in my case both machines are running XP Pro. If you find the answer to the problem please let me know. I upgraded to the Gigabit network because I was unhappy with the 100mb network speed.