Messages in this thread | | | Date | Wed, 23 Oct 2002 13:11:35 -0400 (EDT) | From | "Richard B. Johnson" <> | Subject | Re: [RESEND] tuning linux for high network performance? |
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On Wed, 23 Oct 2002, bert hubert wrote:
> On Wed, Oct 23, 2002 at 03:42:48PM +0200, Roy Sigurd Karlsbakk wrote: > > > The e1000 can very well do hardware checksumming on transmit. > > > > > > The missing piece of the puzzle is that his application is not > > > using sendfile(), without which no transmit checksum offload > > > can take place. > > > > As far as I've understood, sendfile() won't do much good with large files. Is > > this right? > > I still refuse to believe that a 1.8GHz Pentium4 can only checksum > 250megabits/second. MD Raid5 does better and they probably don't use a > checksum as braindead as that used by TCP. > > If the checksumming is not the problem, the copying is, which would be a > weakness of your hardware. The function profiled does both the copying and > the checksumming. > > But 250megabits/second also seems low. > > Dave? >
Ordinary DUAL Pentium 400 MHz machine does this...
Calculating CPU speed...done Testing checksum speed...done Testing RAM copy...done Testing I/O port speed...done
CPU Clock = 400 MHz checksum speed = 685 Mb/s RAM copy = 1549 Mb/s I/O port speed = 654 kb/s
This is 685 megaBYTES per second.
checksum speed = 685 Mb/s
Cheers, Dick Johnson Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips). Bush : The Fourth Reich of America
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