Networked speeds

You might want to disclose how long it took so we can calculate your actually transfer speed.

The best you can do with a 54Mbit/sec connection is about 25Mbits/sec transfer speed. If your 100Mbit/sec PC's are setup for 100baseTX-FDX (full duplex) you should get about 80Mbit/sec. That's about 3 times faster than the maximum wireless speed.

However, reality and maximum wireless speeds are quite different. My guess(tm) is that you're getting much less than 25Mbits/sec. For example, if you have 802.11b compatibility enabled, your maximum transfer speed will be about 14Mbits/sec or almost 6 times slower. If you have any interference, or your connection speed is less than

54Mbits/sec, the numbers will decrease proportionally.

This is stolen from an Atheros PDF at:

formatting link
some additions and corrections by me.

Non-overlapping Modulation Max Max Max Channels ------- | Link TCP UDP | | | | |

802.11b 3 CCK 11 5.9 7.1 802.11g (with 802.11b) 3 OFDM/CCK 54 14.4 19.5 802.11g only 3 OFDM 54 24.4 30.5 802.11g turbo 1 OFDM 108 42.9 54.8 802.11a 13 OFDM 54 24.4 30.5 802.11a turbo 6 OFDM 108 42.9 54.8

The paper claims that encryption is enabled for these calculations, but my numbers seem to indicate that these number are for encryption disabled. Dunno for sure. The Max TCP and Max UDP are the theoretical maximum thruput rates. I don't have numbers for the various Turbo and SuperG modes.

Reply to
Jeff Liebermann
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I have 3 XP Pro machines. Two are connected by LAN cables and communicate at 100 mbps while the third is wireless at 54 mbps. I moved a 700 meg file from one LAN connected pc to the other LAN connected pc. It took two minutes.

I then moved the same file to the wireless pc assuming 4 minutes. However, the time to completion was well over 4 minutes. I know that network speeds fluctuate, but any thoughts why it took substantially longer then 4 minutes to complete.

Thank you

Reply to

Sigh. Typo or idiot error. 25/14 = 1.8 times slower. Thanks.

The actual speed loss is dependent on the presence of an 802.11b signal. If there is only the access point and client running 802.11g, the access point will sniff for 802.11b packets very infrequently. The last time I measured it with WRT54G v1.1 resulted in a max speed of about 20Mbits/sec. However, when I fired up my 802.11b Orinoco Silver on my laptop, but generated no traffic, the thruput dropped to about

12Mbits/sec. When I generated a little traffic on the Orinoco with pings, the thruput dropped to about 10Mbits/sec. I'm not sure this is consistant among all access points as I only tested this one.
Reply to
Jeff Liebermann
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Just enabled? I've gotten much better than that.

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