I wonder if anyone can explain to me why the achieved throughput for an rsync transfer for files across a wireless connection should be different than I expect as I try to explain below? The situation is that I have a local LAN over which I can run a transfer from two different laptops to a wired only desktop machine on which I keep backup files. The two laptops have different wired and wireless NICs. On the wired connection on a 10/100 system I get file transfers down the wire to the desktop at about 11.7MB/s as measured on the gnome netspeed applet, which is about what I would expect since this is around 95mbps and I could easily imagine a 5% loss for TCP overheads. This is the same for both laptops. On the first laptop if I do file transfers via wireless through its iwl3945 wireless card then I get an achieved throughput through my AP using WPA2 encryption at around 0.75 MB/s which corresponds to about 6mbps - and this is on a link which the laptop system tells me is connected at 54mbps. The machine is a few feet from the AP and shows a 100% signal. On the second laptop which runs an iwl4965 wireless card I get around 1.5MB/s, corresponding to about 12mbps for the same conditions. All machines are running F10, but these speeds were the same for F8 before I did clean F10 installs on them all, so the specific version of Fedora seems to be irrelevant here. The way I look at what speeds I would expect is that I would imagine a roughly (estimated) 50% loss due to the WPA2 encryption, so I would hope to see around 27mbps, which corresponds to just over 3 MB/s. So I am seeing a 50% loss roughly on the machine running iwl4965 and another factor of two or so on the machine running iwl3945. Is this a problem with drivers or have I done my maths wrong? The machines are running the stock kernel and drivers and currently am running NetworkManager, though previously I was using wpa_supplicant directly. Either way these details seemed not to change the numbers. Any thoughts on this? I would be interested in being educated about this. -- View this message in context: http://www.nabble.com/Wireless-transfer-throughput--tp21134634p21134634.html Sent from the Fedora List mailing list archive at Nabble.com. -- fedora-list mailing list fedora-list@xxxxxxxxxx To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list Guidelines: http://fedoraproject.org/wiki/Communicate/MailingListGuidelines
