# Network performance

## onlyreece

I just recently installed Gentoo on a PC for use as a file server, however, the speed I am reaching is only about 3.6Mb/s when I know I can reach 11Mb/s.

This appears to be the same with both FTP and SCP for transferring files. 

I am fairly new to linux and would like to know where I should start diagnosing this problem and how I go about changing the card settings.

I am using Gentoo-2.6.12 for my Kernel and my network card is an onboard nForce2 card using forcedeth built into the kernel.

Cheers

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## Dlareh

if you have two linux machines...

emerge netperf

/etc/init.d netperf start

rc-update add netperf default

then run netperf -H otherhostname

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## ChojinDSL

Are you using linux on your client machines as well, or only on the server?

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## onlyreece

The gentoo box is the only linux box I have. All 3 other pcs are Windows XP.

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## Dlareh

cygwin might have netperf...

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## ChojinDSL

With Windows, I have noticed that network transfer speeds are always slower than what I get under linux. With windows, the maximum I ever got on a LAN when transferring files from one client to another was 50-75%. Under linux I get 90-100%.

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## onlyreece

OK I got Netperf for windows, there is a win32 version of 2.1, and I tried that. This is the output I got

TCP STREAM TEST to 192.168.1.120

Recv   Send    Send

Socket Socket  Message  Elapsed

Size   Size    Size     Time     Throughput

bytes  bytes   bytes    secs.    10^6bits/sec

 87380   8192   8192    10.00       8.64

Directly from another site

 *Quote:*   

> This default test should take 10-20 seconds. After its done have a look at the throughput, on a 100 Mbps network this number should be between 85-95 (* 10^6 bits/sec).

 

Now. To explain my setup so someone may be able to help.

I have a linux file server running gentoo, 2.6.12-r9, with the forcedeth drivers built into the kernel for my on board nVidia network card. This box is located in the living room with my Xbox I use to watch vids and listen to MP3s. Both of these are connected via wired 10/100 switch to a wireless access point. This is the 54Mb speed, not lowly 11Mb.

In the hall I have a wireless router, also 54Mb, connected to my cable modem and old laptop I use as my skype phone. It runs windows XP. It is connected by wire to the router. The router connects the living room with the internet and network wirelessly.

In my bedroom I have my main PC which has a 54Mb connection to the router/network and also runs windows XP. 

Now, normally a transfer between my Main PC and the XBox runs at about 1,000 KB/s, roughly 8Mb/s. This is low compared to 54Mb/s because of the horrible reception. But it works fine. However, when I transfer to my new linux box, either SCP or FTP, I am getting no more than 500KB/s, about 4Mb/s. I want to try and find out why this is happening.

Can someone please help?

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## Jerry Gardner

Several suggestions:

1. Are you familiar enough with the TCP/IP protocols and tools such as tcpdump to be able to look at network dumps and examine the timing? Often times you identify bottlenecks this way.

2. There are several Internet sites with Windows network tuning information. Try these to start with:

http://www.dslreports.com/drtcp

http://www.dslreports.com/forum/news,61

This site is oriented towards tuning broadband network performance, but the principles should apply to your situation.

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