Webserver speeds

[#1]

I have been working with my own webserver as talked about is this thread: http://community.plus.net/forum/index.php?topic=61941.new;topicseen#new
I am hosting the site on my Linux server as described but I build each bit directly onto my Windows server using mapped drives. As I also have Apache 2 installed on this it allows me to test the site before going onto my Linux server.
By default this process gaves me some redundancy (Apart from the RAID drives and the UPS). As the site exists identically on both servers I can easily toggle the port forwarding options on my router over to the Windows server if ever I have a problem with my Linux server or if I am doing some sort of maintaince on it.
It was when testing this that I noticed the issue. Both servers are lightning quick at serving the site to me as they are on my local (100Mbit) network but the Windows server did appear to be slightly slower.
I decided to look closer by downloading the same large file from both across the LAN and after giving the download time to settle I got the results as pictured (Wouldn't it be great if your internet connection was this fast).
This is obviously a vast difference. Would this be caused by software or by the network cards in each computer? The Windows machine has a Netgear FA311 card. Cannot remember what is in the Linux machine. Thanks, Sean.

[#2]

The card in the Windows server is a Netgear FA311. The Linux server has a 3com card. The servers are side by side and I cut the cables identical length from the same roll of Cat 5e several years ago. Although some of my network runs of the switch built into the router, the 2 servers run directly into the same switch that my main desktop machine is connected to. This is the machine that I done the test on.
The spec of the servers is available in the hardware section of my new site at http://www.seanbranagh.ie/computing (served by my Linux server). Although this is not complete there is still an old page on my Windows server with more information about the network at http://www.seanbranagh.ie:75/network
Thanks, Sean.

[#3]

There are to many variables to say what is happening. Does both servers have Av running and is it the same version as this can slow file transfer down if its being slowly scanned by Av.
Are the disk both the same speed wise? Memory the same other software running cpu usage? There are just to many things which could effect it including the usage of the download pc.