Beg to differ. Encryption can certainly impact speed. WEP is often doen in software, so the actual encryption and de-encryption of the over the air data is often done by software, and while it doesn't take long to do it, it does take time, and the effect is a loss in throughput on the wireless connection. Most of the time the effect is small compared to other factors. I.E. if you are 802.11b at 11mbps, that is a 1 bit per 90ns. If software add 10ns per bit to that, you fall from 11mbps to 10mbps. In the big scale of things, you aren't likely to notice.
However if you are running at 54mbps, means instead of 18ns per bit, it is 28ns per bit, the performance falls back to about 35mbps. The effect becomes more dramatic on 802.11g at 54mbps, and far more noticeable.
Techman is correct that there are many more factors that go into wireless performance, and unless you want to carry out the tests in an anechoic chamber without WEP or WPA, there isn't a prayer that Wireless speed will match hardwired speed.,
Years ago I thought hardware are infinitely fast compared to software. It wasn't until I was intimately involved in the development of very fast hdd disk controllers that I discovered that 1 microsecond is very very fast when compared to milliseconds, but not so fast when compared to other microseconds...
