Fast jperf, slow copies

[gcc100]

I could use some help. Here is the setup:

AP: Zyxel WAP3205 (300mbps)
NIC: Intel Advanced-N 6205
Client OS: W7 Pro x64
Server OS: Windows 2008 x64, Windows 7 x64
Secuity: WPA2/AES

jperf reports a maximum of 91mbit/s wireless using 8-16 streams. However, whenever I copy a file the best performance I can get is about 32mbit/s (~4MB/s). Trying multiple copies at once doesn't boost throughput at all. 90mbit/s is pretty impressive, 32mbit/s, not so much.

The server should be OK, as I can get over 90MB/s real-world performance from it wired.

Using wireless, the effective performance is indistinguishable from my older SMC N 150mbps, even though the jperf measured performance is about 80% better.

I've done all the normal things of tweaking channels, 20/40 etc. Going to 40 boosted jperf performance, but not "real-world" performance. I've returned everything to the defaults.

Anyone have any ideas on this? It is really strange.

 

[thiggins]

Jperf/iperf results can be misleading because it has very low overhead.

File copy has much higher overhead, hence lower performance.

Are AP and client in the same room? Be sure to separate them at least 10 feet to avoid receiver overload.