I've been trying to figure this out for the past few weeks with no success, so I need some expert help from you guys.

I have a desktop connected directly with a Cat5 to my wireless router. It is running on Ubunutu 11.04 (and I have previously used Fedora with the exact same issue). I have very low transfer rates when I attempt to copy a file from the desktop to the wireless laptop. My speeds are generally 3-4 Mbit/s. I have used iperf and have found that the transfer rate when the desktop is the server is about 4Mbits but when the laptop is the server side, i get speeds around 10Mbits.

What could be causing the problem? When i check my ISP speed I get 15Mbit/s (top speed that I pay for) from both computers. So the problem seems to be just transferring between the Desktop and the laptop.

The Desktop is running Samba, which I understand can slow things down, but even iperf gives me relatively slow speeds.

Any hints or ideas would be greatly appreciated!

Hi,

I need some clarification. You have a wired network in cat 5e i suppose, wich is 100Mbit/s (12,5Mb/s).
When you use laptop as server you get 10Mb/s of speed, right ? When you use the desktop as server you get 3Mb/s. (with iperf)
And both laptop and desktop are connected wired to the router swich ?
Then your isp give you a 15Mbit/s line wich is a little bit less than 2Mb/s. Right? And both computers get it.

Celyr,

I need some clarification. You have a wired network in cat 5e i suppose, wich is 100Mbit/s (12,5Mb/s).

Yes, the desktop / server is wired to the router and is a 100 MBit connection.

When you use laptop as server you get 10Mb/s of speed, right ?

[/I][/B]10 Mbits, yes.

When you use the desktop as server you get 3Mb/s. (with iperf)

3Mbits, yes. Very slow.I get the same transfer speed when I transfer a large file from the desktop to the laptop using samba. The desktop also has a software raid setup, but I do not believe it has contributed. Prior to the software raid setup, I was still having this issue. I'm wondering if it could be a NIC issue, since I have had the same issue with a previous installation of Fedora.

And both laptop and desktop are connected wired to the router swich ?

The Desktop is wired to the router, the laptop is connected by wireless-g

Then your isp give you a 15Mbit/s line wich is a little bit less than 2Mb/s. Right? And both computers get it.

Yes, both the wired desktop and the wireless laptop can get the full 15 Mbits when downloading etc, but not with intra-network transfers.

Hi,

I think you need to focus on the difference between Mbit and Mbyte -> 1 Mbyte = 8 Mbit
When i write 1Mb i mean byte, when i write 1MB or 1Mbit i mean bit :P

If you really are getting less speed in intra network transfers (wich you can do at 54Mbit 6,7Mb/s top speed you will never reach) i'm going to blame the router's switch\AP.
But i think you have to pay more attention to the Mb MB question.

maybe you need to pay more attention as well

upper case B stands for Byte
lower case b stands for bit

MB= megabyte
Mb= megabit

GB=gigabyte
Gb=gigabit

etc
and lets not complicate it with (GiB and GB) :P

Celyr,

Thanks for your help and reply. Sorry if I am ignorant on the issue, but I understand that a Megabit (Mb or Mbit) is smaller than a Megabyte MB (see http://www.oempcworld.com/support/MB_vs_Mbits.htm; see also, http://mybroadband.co.za/vb/showthre...-Mbps-vs-MBps; , where I got that understanding) All of the rates that I am reporting are in Megabits (Mb) not Megabytes (MB). I.E. they are very slow. I have been careful to compare only Megabits to Megabits, and have not made any measurements or made any report of MB (Megabyte) transfer rates. I have a 15Mb (bits) connection from the provider, and my transfer rates in the network are 10 Mb (bits) when the laptop is "acting as server" and 3 Mb (bits) when the desktop acts as server.

I am okay with the 10Mbits when transffering from the laptop even though I understand it should be faster, but the 3Mb is driving me crazy. I just can't understand why I am able to get a download speed that is significantly faster (which tells me it isn't any restriction of my wireless or router since it can handle faster speeds when downloading, it has gone up to 25Mbits/s with "Cox PowerBoost").

I will connect the laptop to the router tonight and see if that makes any difference. Make sure this isn't just a wireless issue (I am in an apartment complex so have considered that interference could be an issue, but still can't understand why download speeds don't seem to be hindered even when connected wirelessly.)

i am really no expert on this area but if you can have nearly the same download/upload speed from the internet (with wireless and wired) then that would probably mean the bottleneck is not in network equipmnet

and as you mentioned copying speed, for me it seems, as reading is faster the writing speed on hdd
then i would say your laptop hdd is the weak link here. it has a lot lower speed writing then ur desktop

i mighbt be wrong, it was just an idea

I connected the laptop with a wired connection and got the following results which only confuse me more.

112MB at a rate of 94Mbits/s with laptop as server.
112MB at a rate of 93.8MBits/s with desktop as server.

Why is my wireless connection limiting my transfer rate only one way in intra network transfers, but having no restriction or difficulty with internet download speeds? Very confused.

This is more normal than you think.
modem router and access point all-in-one work very bad. I Suggest you to buy a switch and an Access Point, you will get very good results.

Celyr:

Thanks. I may try this and see if that helps at all. Much appreciated!

As stated there are many factors and some wireless routers work better then others but in general I disagree with the statement. Routers do go bad. I've recently had to replace an old WRT54G due to the wireless becoming erratic.

What is the make/model of your router?
How is wireless configured?
What is the make/model of your laptop?
What is the wireless adapter? (Look at the output of the lspci command)

How far is the laptop from the router?
How much stuff i.e. walls are in between the two.
Post the output of the iwconfig command.

Have you tried moving the laptop closer to the router?
What other 2.4 GHz wireless devices do you own like cordless telephones, baby monitors etc. What about your neighbors?

In addition if the wireless adapter TX pwr was low or weak then the upload speed would be slower due to retransmissions vs just downloading the data. Being a client there is less data transmitted vs being a server.