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Re: NIC transferring twice its max rate

On Wed, Jan 25, 2012 at 09:39:40AM -0500, Rob Owens wrote:
> I've got an onboard NIC, supposedly 100Mb.  I've been doing a dd over
> ssh for the last hour, and iftop tells me that I'm transmitting at a
> steady 186Mb, while receiving about 1.2Mb.
> I read up a bit on full duplex, and as I understand it full duplex means
> the NIC would be capable of transmitting a theoretical max of 100Mb
> while simultaneously receiving 100Mb.  My card seems to be transmitting
> at nearly double its theoretical max.
> Is this possible, or is iftop lying to me?
> I've got gigabit networking between the two computers, and the second
> computer has gigabit ethernet.
I just ran iftop on the second computer, and it reports receiving at a
rate of 92Mb.  So apparently iftop is lying to me, at least on one of
the computers.

I guess I'll find out which one is telling the truth (if any) based on
how long it takes for this 160GB transfer.


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