Poor file transfer rates?

habrys · Post by **habrys** » 22 Apr 2007, 17:19

I just got my bubba and am pretty impressed with the all the things this tiny box can achieve. However... are the file transfer rates pretty bad or am I missing something?

I performed a few tests on a 100Mbit cable network. Following devices were attached:
1 desktop pc (feisty)
1 laptop (dell)
bubba
to a Netgear WGR614-v4 router

Both computers ran under ubuntu 7.10 Feisty Fawn. Bubba was mounted via smbfs file system.

Samba transfer rates:
dell -> feisty: 3.94 MB/s
bubba -> feisty 1.94 MB/s

I observed cpu load of bubba during transfer with top utility and noticed, that smbd eats nearly all cpu resources. 0-2% idle. (The test itself was ran without top process running though - it can eat 5-10% of cpu time.)

So is this tiny arm the bottleneck for file transfer rates? I decided to compare transfer rates over ftp with and without some other processes running on bubba.

FTP transfer rates:
idle bubba -> feisty: 4.05 MB/s
bubba running 3 torrents -> feisty: 3.1 MB/s

And here again proftpd process tried to use all available cpu resources.

How do you think - would it help to install a faster arm processor? Is it possible at all?
Is my conclusion right: the bottleneck for file transfer rates from/to bubba is its cpu?

Post by **johannes** » 22 Apr 2007, 17:36

habrys,

You are correct in principle, the CPU is the main bottleneck. Since SAMBA is a more CPU intensive protocol than FTP, it's correct that SAMBA is slower than FTP. HTTP transfers is even faster than FTP, because of the even lesser CPU load that protocol has.

Installing a faster CPU isn't possible unfortunately. The somewhat limited transfer speeds is the price we had to pay when choosing a CPU that doesn't generate heat, and one of our main objectives was to keep Bubba fanless.

Anyway, I hope you can live with that.

habrys · Post by **habrys** » 22 Apr 2007, 18:51

Thank you for a quick answer, johannes. Sure I can live with that, the transfer rates are not so bad after all

One more question: is NFS less CPU intensive protocoll, than SAMBA ore even FTP? I'm aware of the fact, that NFS daemon is not available on the Bubba out of the box, but it shouldn't be a big problem to add this functionality via debian repositories. And since most of my network consists of Linux boxes, it would be an interesting alternative for me.

So is it worth a try?

Clive · Post by **Clive** » 23 Apr 2007, 03:25

I use Suse Linux and when I used the Konqueror explorer to access the smb share it is very slow (4-5MB/s) but since then I have mounted the Bubba share onto my machine and speed seems to be alot faster. I stream video off it via the mount with a number of torrents going on at the same time. Never had any problems with lock-ups indicating slow transfer rates.

I know others have loaded up NFS and claim it is 'significantly faster' (see this thread - http://www.excito.org/forum/viewtopic.p ... hlight=nfs)

habrys · Post by **habrys** » 23 Apr 2007, 04:17

I know others have loaded up NFS and claim it is 'significantly faster' (see this thread - http://www.excito.org/forum/viewtopic.p ... hlight=nfs)

Sounds interesting, I'll definitely try it out. Thanks for the link, Clive.

And again I asked a question (about NFS) before searching the forum properly...

habrys · Post by **habrys** » 24 Apr 2007, 17:53

I installed the NFS server and tested the transfer rate via NFS today. Here is the result if someone is interested:

bubba -> feisty via nfs: 2,51 MB/s

And again nfsd processes used all cpu resources...

I hope it'll be enough to stream full HD movies. I've read somewhere about 25 Mbps bitrates. We'll see...

Clive · Post by **Clive** » 25 Apr 2007, 02:10

Just tried a quick test myself copying a 1.2GB file from Bubba to my Suse Linux box.

With the NFS mount ~3.8 MB/s
With the SMB mount ~2.9 MB/s

So NFS does seem a tad faster in my case. Not sure these speeds could work too well with HD streaming.

rasel · Post by **rasel** » 18 Oct 2007, 05:18

I can't get near these speeds. From Bubba to XP pc while copying files, I have ~500kb/s. Is this normal?
Must I install Linux to the other PC to get faster transfer speeds?
I have an adsl modem with a 10/100Mps switch between bubba and xp machine.

Post by **johannes** » 18 Oct 2007, 12:08

500 kb/s is not normal regardless of what protocol you are using, it should reach what the other guys have seen, at least 2.5 MB/s with SMB (windows share).

Since the CPU is Bubba's main bottleneck, other simultaneous operations will affect the speed. Perhaps the UPnP server (mediatomb) is indexing your music collection? You can check if anything else is eating CPU resources using the 'top' command when logged on with ssh.

Also, I assume you have a wired connection (not WiFi) between bubba and your workstation?

rasel · Post by **rasel** » 19 Oct 2007, 03:53

I checked the CPU usage with "top", CPU seems to be around %85 idle while copying 2gb. Yes, I have a wireless ADSL modem with a 4 port wired ethernet interface on it. I have 2 desktop PCs connected to ports and the third one is bubba. Notebooks are connecting to the system with wireless. I don't have any problem with the 2 window pcs copying files over the switch. I booted a pc with a live knoppix cd and try copying the files, again %85 cpu idle but this time I recognized, the modem's web interface stops responding, my internet connection also droped. Until the copying finished, then everything went to normal. I think the modem is the bottleneck in this case. But why I have no problem before with the two pc connection, I don't know. May be the third port is not working well. I'll try with an external switch this weekend. Thanks for the reply.

rasel · Post by **rasel** » 20 Oct 2007, 10:46

Hello again,

I couldn't test the system with my old switch because I can't find it around the garage. But now I have more info and before going and getting a new switch, I want to say this:

When I changed the eth0 setting on bubba with 10Mb/s full duplex, I got a stable 1Mbs speed both with samba share and ftp download. This is better than my 100Mb/s setting at which I get only 500Kb/s (unstable, changing from 100Kb/s to 800Kb/s all the time) both with samba and ftp transfers. Anybody with a better network knowledge can now say something may be?

Regards.

rasel · Post by **rasel** » 20 Oct 2007, 11:16

I found another info by the help of net, after a simple copy, I got lots of RX errors:

eth0 Link encap:Ethernet HWaddr 00:03:1C:FF:F2:CC
inet addr:10.0.0.3 Bcast:10.0.0.255 Mask:255.255.255.0
UP BROADCAST RUNNING ALLMULTI MULTICAST MTU:1500 Metric:1
RX packets:8692 errors:198 dropped:0 overruns:0 frame:198
TX packets:15632 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:587190 (573.4 KiB) TX bytes:22412780 (21.3 MiB)
Interrupt:24 Base address:0xc000

rasel · Post by **rasel** » 21 Oct 2007, 01:58

I found the cause of RX errors, if I dropped the line speed of bubba to 10Mbs, the errors occur but I also get a stable 1Mb/s transfer speed. If I set the line speed to autoneg on, bubba sets the speed to 100Mbs full duplex, no errors occur but I get unstable speeds of average 200Kb/s