The systems:

Del Optiplex w/ 1GB eth card , win7

mini-itx system, jetway nf98, intel i3,1 GB onboard eth card, crux w/ custom

The network: cat 5e or 6 all around. systems are less than a foot from each other. longest cable is 6 feet. have tried variations of router only, router and switch, switch, or direct connect (no router, or switch) (switch & router are gig too btw)

the share:

i mount the crux system on the windows system using samba

i mount the windows share on the crux system using 'mount -t cifs'

NOTE: variations of only one mount at a time, both mounts at a time, prob anything you can think of

Transfer 1: while using the win7 system, i start>run>\192.168.x.xxx\share and up pops an explorer box displaying the contents of my internal drive on the crux system. i then drag a 10g file from the share to the desktop of the win7 system. 10g file was made 'dd if=/dev/sda of=/a/10g.dd bs=1M count=10240' THIS results in a transfer at speeds: 55mb/s (lowest) to 105mb/s (highest) and avgerages about 75mb/s. [these results are above goal]

Transfer 2: while using the crux system, i mount the win7 share ('mount -t cifs-o //192..../share /a'), and ls -l /a displays contents of win7 drive's share. i then time a copy of a 10g file from the share to the internal drive of the crux system. THIS results in transfer speeds: 5m23s so ~ 31 mb/s

why are the results so different?

the highest i can set mtu on crux w/ this card is 4000, but that seems to have affect of zero.

i also try dd, using bigger block sizes, which gives little improvement

EDIT: It occurred to me that it might be the windows7 copy is faster/better. SO, from the windows machine, in cygwin, i executed 'time cp //192.../share/10g.dd /cygdrive/c/../Desktop Resulted in 2m51s ~ 59mb/s

  • The title and text keep on mentioning "network transfer" and "transfer". Your tests are more timings of a file copy rather than "network transfer speed", and the bottleneck is probably at the file creation/write rather than the "transfer". What happens if you eliminate the network, and just perform local disk-to-disk copies? This would provide a reference time for each filesystem, that is, ntfs and ext4(?).
    – sawdust
    Dec 7, 2011 at 22:24
  • You should also try reversing the direction of the file copies, or what you call "transfers 1 and 2".
    – sawdust
    Dec 7, 2011 at 22:59

1 Answer 1


What are the specifications of every card (chipset, etc).

There can be huge difference in performance between cards. As an example, server / enterprise grade cards have their own circuits to perform tasks that in basic cards are delegated to the main processor.

So, may be, it is just a difference in hardware performance.

  • crux system's nf98 motherboard (intel QM57 @ 3.5W) onboard lan: Intel 82577LM Gigabit Ethernet optiplex 380 ( Intel® G41 Express Chipset with ICH7): Broadcom® Integrated Gigabit Networking (BRCM 57780)
    – c card
    Dec 7, 2011 at 20:56
  • @jap1968, if you need to ask a question, it isn't an answer, please use the comments fields to get more information in order to provide a complete anaswer.
    – Paul
    Dec 7, 2011 at 23:06
  • @Paul: Ok. My mistake
    – jap1968
    Dec 8, 2011 at 18:10

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