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davidblewett
Apprentice
Joined: 15 Feb 2004
Posts: 274
Location: Indiana
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 Posted: Fri Apr 09, 2004 12:14 pm Post subject: Home Network Speeds |
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| I was doing some large transfers on my network at home last night, and was wondering why all of them topped out at 2.5MB/s? It is a simple network between 2 machines, both with 10/100 NIC's connected through a 10/100 hub. I know that hubs aren't the best option, but it shouldn't matter if there are only 2 machines on correct? Any ideas on increasing the throughput? |
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EdSchouten
Tux's lil' helper
Joined: 07 Oct 2003
Posts: 79
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| Posted: Fri Apr 09, 2004 12:18 pm Post subject: |
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| What kind of NIC's are you using? |
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davidblewett
Apprentice
Joined: 15 Feb 2004
Posts: 274
Location: Indiana
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| Posted: Fri Apr 09, 2004 12:20 pm Post subject: |
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| I'm not sure of the brands at the moment, I'll check when I get home. One is using the via-rhine driver and the other is using the epic100 driver. |
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EdSchouten
Tux's lil' helper
Joined: 07 Oct 2003
Posts: 79
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| Posted: Fri Apr 09, 2004 12:22 pm Post subject: |
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hmmmm...
Never worked with those NIC's, can't tell you if they are good or bad  |
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bobwarlock
n00b
Joined: 17 Sep 2003
Posts: 22
Location: Lincoln, NE
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| Posted: Fri Apr 09, 2004 4:11 pm Post subject: |
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You aren't by chance copying these files over an SSH connection (sftp, scp, etc) are you? SSH adds a huge overhead meaning you'll rarely get above 4-5MB/sec. I usually get around 2-4MB/sec when I do it on my 100BT switched network. The reason has something to do with how every block of data sent requires an acknowledgement from the receiving end I think.
Of coures, if you're using plain old FTP or something then the above is irrelevant 
One other thing you could check is that your hard drives aren't the limiting factor. Do a | Code: | | hdparm -tT /dev/hda |
(or whatever your drive is) on both machines and make sure you're getting reasonable results there. |
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davidblewett
Apprentice
Joined: 15 Feb 2004
Posts: 274
Location: Indiana
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| Posted: Fri Apr 09, 2004 4:19 pm Post subject: |
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| I think you hit the nail on the head. I indeed was using scp. I'm setting up NFS this weekend, so I'll see what that is like. |
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Crg
Guru
Joined: 29 May 2002
Posts: 345
Location: London
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| Posted: Fri Apr 09, 2004 4:26 pm Post subject: |
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| bobwarlock wrote: | One other thing you could check is that your hard drives aren't the limiting factor. Do a | Code: | | hdparm -tT /dev/hda |
(or whatever your drive is) on both machines and make sure you're getting reasonable results there. |
Why oh why must people continue to tell others to test their harddrives like
hdparm -T is not going to show you if he has DMA enabled, it's just testing the file cache, ie not actually touching his drive.
Forget -T already
Anyway... davidblewett:
Does dmesg show any errors?
Does "ifconfig" show any errors for your network card?
Can you run "ttcp" (emerge ttcp) on two machines and test the network speed with it?
Re: scp, I get 16.5MB/s between 2 athlon machines which drops to ~3MB/s if compression is on. |
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davidblewett
Apprentice
Joined: 15 Feb 2004
Posts: 274
Location: Indiana
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| Posted: Fri Apr 09, 2004 4:49 pm Post subject: |
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| Crg wrote: |
Anyway... davidblewett:
Does dmesg show any errors?
Does "ifconfig" show any errors for your network card?
Can you run "ttcp" (emerge ttcp) on two machines and test the network speed with it? |
I will try your suggestions this weekend. I heard about netio too, and I'll try that.
| Crg wrote: |
Re: scp, I get 16.5MB/s between 2 athlon machines which drops to ~3MB/s if compression is on. |
I think I had compression on when I was doing the scp. Should I not do that? I was copying over /usr/portage to a new machine, so the compression probably didn't even help because they're mostly bz2's already. (Yeah, I know NFS is a better way and I'll be doing it this weekend.)
_________________
No guilt in life, no fear in death
this is the power of Christ in me
From lifes first cry to final breath
Jesus commands my destiny
-- Newsboys, "In Christ Alone", "Adoration: The Worship Album" |
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bobwarlock
n00b
Joined: 17 Sep 2003
Posts: 22
Location: Lincoln, NE
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| Posted: Fri Apr 09, 2004 10:50 pm Post subject: |
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| Crg wrote: | Why oh why must people continue to tell others to test their harddrives like
hdparm -T is not going to show you if he has DMA enabled, it's just testing the file cache, ie not actually touching his drive.
Forget -T already |
... because I, like many others, am a sheep! Baaaaaaaa! Seriously though, that was an error on my part. I knew -T tested cache, I've just got the bad habbit of typing -tT automatically for the heck of it.
Crg is right in that -t is the useful option.
| Crg wrote: | | Re: scp, I get 16.5MB/s between 2 athlon machines which drops to ~3MB/s if compression is on. |
You get 16.5MB/s with scp? Do you do anything special (options) to acheive this? I know the -C option enables compression, but even without it I've never seen speeds above 5MB/s (even between two 2.53GHz PIV's). I've been longing for a way to make scp speedy. |
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davidblewett
Apprentice
Joined: 15 Feb 2004
Posts: 274
Location: Indiana
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| Posted: Mon Apr 12, 2004 12:27 pm Post subject: |
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Okay, I was moving over some mp3's and noticed that the throughput had jumped to 3.5MB/s. I didn't get a chance to run ttcp, but I did notice that I'm getting alot of collisions. Is there a way you can force 100baseT, full duplex negotiation? When I tried to do ifconfig eth0 IPAddr media 100baseT, I got an error. I'm not getting any errors on dmesg.
_________________
No guilt in life, no fear in death
this is the power of Christ in me
From lifes first cry to final breath
Jesus commands my destiny
-- Newsboys, "In Christ Alone", "Adoration: The Worship Album" |
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echto
Tux's lil' helper
Joined: 30 Jun 2002
Posts: 108
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| Posted: Mon Apr 12, 2004 12:36 pm Post subject: |
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Collisions are a normal thing for TCP/IP - its going to happen; CSMACD - Carrier Sence Multiple Access Collision Detect.
I'd be worried if your weren't having collisions! |
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Crg
Guru
Joined: 29 May 2002
Posts: 345
Location: London
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| Posted: Mon Apr 12, 2004 6:59 pm Post subject: |
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| bobwarlock wrote: | | You get 16.5MB/s with scp? Do you do anything special (options) to acheive this? I know the -C option enables compression, but even without it I've never seen speeds above 5MB/s (even between two 2.53GHz PIV's). I've been longing for a way to make scp speedy. |
Yeah I cheated It was over a rubbish gigabit link (rubbish because it's between 2 cheap gigabit cards that don't get real gigabit speeds with the latest kernels only getting 18100KB/sec (ttcp)).
Just tested it over a 100/switched which gets about 8100KB/sec (ttcp), and I only get ~5MB/s. |
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