I have been performing the same test with 3 different Wi-Fi routers (ASUS RT-N 16, Netgear WD3700 and Netgear WD4500):
- Turn on the router and plugin external HDD.
- Connect to the router from one of two different laptops (both using 802.11n), while placing the laptop inches from the router.
- Copy a big file from the laptop to the external HDD over Wi-Fi.
No matter what router, laptop or frequency (2.4 or 5.0) I used, my file transfer speed never went above 6.0MBps (with Netgear WD4500) or 3.5MBps (with any other router).
Why is it so much lower than theoretical maximum?
Few things that I have already ruled out:
- One of the laptops is brand new ASUS UX31a running Windows 7, another one is an older Toshiba with Windows XP. Transfer speed is almost identical on both of them, so it should not be an issue with the laptop.
- When HDD is connected directly to the laptop via USB, the transfer speed hovers around 20MBps, so HDD can't be limiting factor either.
- While doing the test, no other computers were connected to that Wi-Fi network.
- All routers were brand new, running stock firmware.
- InSSIDer shows that there is just one another router in vicinity, running only at 2.4 frequency and at different channel than my router.
Am I missing something obvious?