When I initiate an sftp transfer from my server to my laptop, it will start at several hundred kB/s and then drop off to and settle at about 100kB/s. This happens with http transfers also. It's not all network traffic though because bittorrent downloads on the server regularly hit my max internet speeds of 1.5mB/s. This happens on my new router and my last one.

My hard drive isn't the problem because I don't have these slow speeds copying from the hard drive to a USB flash drive. But I still have them transfering a file over the network from the internal flash.

My server is an OLPC XO-1 which is a low power server but neither CPU or memory are pegged during transfers.

The transfer is happening over wifi in both directions.

This happens on other clients on the LAN and internet.

I have little to no packet loss in either direction.

I would suggest configuring QoS and give bittorrent traffic less priority, or the ports for the protocols you are using more priority.

I hope your router does supports this but I believe nowadays this is rather common.

Also what I did is configuring the speed of my router to around 90 or 95 percent of the maximum of my internet connection.

Or maybe you have just too many open connections?

Can you see any statistics of the router?

It could be good to check the QoS as deadeyes says, but I wonder if there is a limitation in the server? Does anyone else get higher throughput towards the server? It could show higher in the beginning until it stabilizes...

Is it only download? Or are you running simultaneous up/down? If you are running up and down simultaneous there could be need for tcp ack prioritization (to avoid choking the download). But I guess you only run dl?

If you control the server you could changing the ports and see if that helps.
Does any of the cpu's peak while downloading?

One could check the tcpdump/wireshark and see the tcp throughput graph and see if it looks like a straight line or if it gets chopped.

/C

Wireless is always tricky.

Do you get the same result when you are close to the wireless router?

If I want performance I just connect to my GB ethernet network