I have a small home network running (3 PCs) all with Windows XP, 1 with SP2, 2 with SP1. All have been updated via Windows Update. I recently upgraded to a Gigabit Ethernet network from my 10/100. I'm not getting the speeds I'm expecing, so I decided to test. I transfered 3.46 GB worth of files. Here are my calculations of Mb to MBps. 3.46 GB @ 1 Gbps = 27.68 seconds 3.46 GB @ 512 Mbps = 54.0625 seconds 3.46 GB @ 100 Mbps = 276.8 seconds (4.61 Min.) This is the ideal situation, but I'm not getting anywhere near this. *Test 1 (WXP SP1 to WXP SP2) Using Gigabit cards, cables and switch. 3.46 GB in 5:12 Actual speed = 88.72 Mbps *Test 2 (SP1 to SP1 machine) Thinking it may have been the slow PCI bus I used integrated NIC cards in Test 2 (Using integrated 10/100 LAN) 3.46 GB in 10:13 Actual speed = 45.12 Mbps *Test 3 (SP1 to SP1 machine) (restarted switch, disconnected everything except two computers and DHCP Server) 3.46 GB in 10:03 Actual speed = 45.84 Mbps *Test 4 (SP1 to SP1 machine) (replaced switch with old 10/100 one, just two computers and DSL DHCP Server connected) 3.46 GB in 10:03 Actual speed = 45.84 Mbps *Test 5 (SP1 to SP1 machine) (Thinking its some ethernet setting or cable or something related, I setup a firewire network) (Firewire) 3.46 GB in 3:46 actual speed: 122.4 Mbps *Test 6 (SP1 to SP1 machine) (gigbit, only two computers and DHCP Server connected) 3.46 GB in 11:50 Actual speed = 38.96 Mbps *Test 7 (SP1 to SP2 Machine) (gigabit only two computers and DHCP server connected) 3.46 GB in 9:33 actual speed = 48.3 Mbps As you can see I'm not getting anywhere near gigabit speeds or even 1/4 gigabit speed. I tried increasing the TCPWindowSize in the registry to maximum, but it had little or no effect. I updated all the drivers (used the one Windows Update recomended), no effect. I'm using CAT6 cables about 25 ft long. I didn't have a crossover cable or else I would have tried that. The DSL DHCP server is connected via 50 ft. Cat5e cable. I'm using an Airlink 101 8 port gigabit switch and Airlink gigabit cards. I feel as if I've done everything but reformat all my systems! Any help would be appriciated! -Jason