I have an Intel Wireless WiFi Link 4965AGN adaptor in my laptop (HP Pavillion dv2000 series) which is connecting to a 5Ghz-only 802.11n network provided by an Apple Airport Express. The network is using WPA2 encryption. My desktop is also connected the Airport, via a Linksys WUSB600N USB adaptor. Both are running with the latest drivers, and the Airport is running the latest firmware. The Airport is also configured to use wide channels.

The problem I have is that I never get throughput above 4MB/s when transferring files between the two machines. Even a pessimistic calculation shows a 270Mbps network as being capable of transfer rates at well above 10MB/s.

I'm pretty sure I've isolated the issue to being the Intel adaptor, as wiring the desktop to the AP, and using the Linksys adaptor on the laptop immediately yielded speeds limited by the 100MB/s ethernet connection.

I know that 802.11n is still a draft standard, and so mixing kit from different manufacturers can easily lead to poor results, but I was just wondering if anybody else out there has had success with this Intel adaptor on an N network? Or even better, connecting it to an Airport Express?

Can anybody give me any advice on how to troubleshoot this issue? I should also mention that the Airport Express doesn't allow you to manually specify channels when running in N mode, and that I've been able to rule out interference from other Wireless LANs by scanning. There aren't any other 5GHz networks in my area.

All ideas welcome!

Update: A while later, I've just updated to the most recent drivers for both the Intel chip in the laptop, and the USB adaptor. Unfortunately this hasn't improved things :(. If anybody has any advice it would be be gratefully received.