I have an iMac Core Duo and a new MacBook Core 2 Duo.

I've been transfering files between the two over the past week and noticed that the transfer rate is around 20MB/s ... Not to bad. But shouldn't I be getting upwards around 40 - 50MB/s?

Yes, I understand that both have a GB ethernet connection. But it's currently being used with my internet.

Both computers have manual IP addresses and it doesn't seem to matter if I have IPv6 on or off.

Any help would be appreciative.