Slow download speed on Ubuntu 12.10 vs Windows

[dani.rab]

Hey great community, I need your help with understanding why my internet speed (especially the download speed) is so slow on my Ubuntu machine. check this speed differences between my Windows and Ubuntu machines:

Windows:

windows.png

Ubuntu:

ubuntu.png

it used to be ok a few days ago, I don't have a clue what changed that now it's so slow.
I tried searching for a solution but everything I tried did not work.

The Ubuntu machine is connected with a wired and wireless connection, I tried disabling one of them but it did not help.

[varunendra]

Welcome to the forums dani.rab !

Please follow the "Wireless Script" link in my signature, download and run the script as per instructions there, and post back the report it generates.

While posting the outputs, please use 'Code' tags. It preserves the output's formatting and makes the post cleaner, compact and more readable. To see a quick 'HowTo' with screenshots, please follow the "Using Code Tags" link in my signature.

[dani.rab]

thanks for the help Varunendra, here's the output of the wireless script:
http://goo.gl/Un6p8Z

[coffeecat]

Thread moved to Networking & Wireless.

[varunendra]

Have you checked the speed with only the wifi connected (and wired disconnected)?

Because both are currently connected, both have (same) gateway defined but different DNS servers. This *may* cause some confusion about routing table preferences unless we check "route -n" as well along with other outputs. Besides, Network Manager is designed to prefer the Wired connection if available.

If using only the wireless connection gives you the same slow speeds, try this first -

Open a terminal (Ctrl-Alt-T) and run the following command -

sudo modprobe -rv rt61pci
sudo modprobe -v rt61pci nohwcrypt=Y

Then connect again and see if it helps improving the speed. This will be a temporary change that will be lost at next boot. If it seems to help, we can make it permanent.

If the above trick doesn't help, try changing the encryption type in your router to pure WPA-PSK, AES/CCMP. Currently it is set to use WPA/WPA2 mixed mode with TKIP, which should be avoided at all costs.

Additionally, you may (probably should) also try changing the channel to 1 or 11. These usually work better with Linux drivers.

Try one at a time (nohwcrypt=Y first, change of encryption and channel next), and if neither seem to make any significant difference, try the nohwcrypt=Y option WITH the changed encryption too.

Let us know the outcome.

[dani.rab]

we're making progress, using only the wireless connection improved the speed significantly. I got these results:
Download Speed: 11.6 Mbps (1.45 MB/sec transfer rate)
Upload Speed: 4.24 Mbps (0.53 MB/sec transfer rate)

Changing the nohwcrypt or the encryption had a very small affect.

Still the download speed is much lower than windows (40 Mbps vs 12 Mbps).

Is there something else I can try?
why is the wired connection so slow? shouldn't it be faster?

[varunendra]

why is the wired connection so slow? shouldn't it be faster?

Yes it should. But there can be many things that can go wrong. I have no reason so far to believe that it was the wired connection alone that was itself slow. It could be some confusion/conflict at the OS level as well.

If using only the wired connection alone gives the same slow speed again, we can try a few things to make it faster. That would be a whole different issue, and should be kept entirely separate from the wireless issue currently at hand.

As for the wifi, did you also change the encryption as suggested? The TKIP encryption is not nearly as efficient as the AES/CCMP I suggested, and is often the cause for slow speeds.

[dani.rab]

As for the wifi, did you also change the encryption as suggested? The TKIP encryption is not nearly as efficient as the AES/CCMP I suggested, and is often the cause for slow speeds.

Yes, I tried the AES encryption, I saw a very small improvement.

If I just use a wired connection, the speed is very slow.

basically I prefer using the wired connection, but currently I'm connected by WIFI because of the slow speed issue.

[varunendra]

Hmm.. let's see if there is anything we can do to further improve the speed.

For the wireless, please re-run the script (with all the recommended changes applied and ethernet disconnected) and post back the result along with the outputs of -

ifconfig
route -n
ping -c4 google.com

And a fresh speedtest result (screenshots aren't necessary, your description would be enough).

For the wired connection, please install ethtool (sudo apt-get install ethtool) and post back the outputs of (while Only the ethernet is connected and wifi disabled) -

ifconfig
route -n
ping -c4 google.com
sudo ethtool eth0

[dani.rab]

wireless results:
Download Speed: 13.75 Mbps (1.72 MB/sec transfer rate)
Upload Speed: 4.22 Mbps (0.53 MB/sec transfer rate)
Latency: 11 ms

output of script:
http://goo.gl/5K9xkX

output of commands:

dan@ubuntu:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr <REMOVED>  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)


lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:987 errors:0 dropped:0 overruns:0 frame:0
          TX packets:987 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:411421 (411.4 KB)  TX bytes:411421 (411.4 KB)


wlan0     Link encap:Ethernet  HWaddr <REMOVED>  
          inet addr:192.168.11.54  Bcast:192.168.11.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:36958 errors:0 dropped:0 overruns:0 frame:0
          TX packets:27927 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:44719985 (44.7 MB)  TX bytes:13014912 (13.0 MB)


dan@ubuntu:~$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.11.1    0.0.0.0         UG    0      0        0 wlan0
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 wlan0
192.168.11.0    0.0.0.0         255.255.255.0   U     9      0        0 wlan0
dan@ubuntu:~$ ping -c4 google.com
PING google.com (74.125.224.130) 56(84) bytes of data.
64 bytes from lax02s20-in-f2.1e100.net (74.125.224.130): icmp_req=1 ttl=52 time=14.9 ms
64 bytes from lax02s20-in-f2.1e100.net (74.125.224.130): icmp_req=2 ttl=52 time=23.3 ms
64 bytes from lax02s20-in-f2.1e100.net (74.125.224.130): icmp_req=3 ttl=52 time=22.8 ms
64 bytes from lax02s20-in-f2.1e100.net (74.125.224.130): icmp_req=4 ttl=54 time=14.5 ms


--- google.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 14.582/18.927/23.370/4.178 ms

wired connection results:
Download Speed: 0.45 Mbps (0.06 MB/sec transfer rate)
Upload Speed: 0.89 Mbps (0.11 MB/sec transfer rate)
Latency: 12 ms

dan@ubuntu:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr <REMOVED>  
          inet addr:192.168.11.2  Bcast:192.168.11.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:126 errors:0 dropped:0 overruns:0 frame:0
          TX packets:242 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:20837 (20.8 KB)  TX bytes:28471 (28.4 KB)


lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:1431 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1431 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:449928 (449.9 KB)  TX bytes:449928 (449.9 KB)


wlan0     Link encap:Ethernet  HWaddr <REMOVED>  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:68525 errors:0 dropped:0 overruns:0 frame:0
          TX packets:51044 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:84336975 (84.3 MB)  TX bytes:25652632 (25.6 MB)


dan@ubuntu~$ route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.11.1    0.0.0.0         UG    0      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth0
192.168.11.0    0.0.0.0         255.255.255.0   U     1      0        0 eth0


dan@ubuntu:~$ ping -c4 google.com
PING google.com (74.125.224.225) 56(84) bytes of data.
64 bytes from lax04s08-in-f1.1e100.net (74.125.224.225): icmp_req=2 ttl=52 time=20.4 ms
64 bytes from lax04s08-in-f1.1e100.net (74.125.224.225): icmp_req=3 ttl=50 time=14.7 ms
64 bytes from lax04s08-in-f1.1e100.net (74.125.224.225): icmp_req=4 ttl=54 time=10.8 ms


--- google.com ping statistics ---
4 packets transmitted, 3 received, 25% packet loss, time 7037ms
rtt min/avg/max/mdev = 10.806/15.326/20.463/3.966 ms

dan@ubuntu:~$ sudo ethtool eth0 
Settings for eth0:
	Supported ports: [ MII ]
	Supported link modes:   10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	Supported pause frame use: No
	Supports auto-negotiation: Yes
	Advertised link modes:  10baseT/Half 10baseT/Full 
	                        100baseT/Half 100baseT/Full 
	                        1000baseT/Full 
	Advertised pause frame use: No
	Advertised auto-negotiation: Yes
	Speed: 1000Mb/s
	Duplex: Full
	Port: MII
	PHYAD: 1
	Transceiver: external
	Auto-negotiation: on
	Supports Wake-on: g
	Wake-on: g
	Link detected: yes