Recommended PCI gigabit ethernet card? OT: PC Gigabit Through put Question

[Tom Buskey]

On 6/14/07, Flaherty, Patrick <pflaherty at wsi.com> wrote:
>
> I'm not the best with these bit/byte problems so I might be wrong,
> but.....
>
> A PCI bus can pass 1056 bits a second (32 bit, 33 mhz)
> tcp/ip over head is somewhere around %20 (1056 * .8 = 844.8)
>
> What can you reasonably expect a pci gigabit card to give you for
> through put?


The author of O'Reilly "Unix Backup & Restore" says you should expect a
maximum throughput around 50MB/s for backups over gigabit.


PCI Buses are generally shared (save high end server boards) right?


Yep.  Higher end systems will have multiple PCI buses.  The Sun v890 has 4
seperate buses and you can distribute the cards based on


On top of that, if hdparm says timed disk writes are around 40MB, what
> could you see for sustained download speeds? Maybe a static cached
> webpage could saturate a gig connection, sustained 5 gig http download
> couldn't right?
>
> Anyone have real world answers for that stuff?


What if you're downloading to RAM disk?
When I've been doing my network measurements I've been going from /dev/zero
to /dev/null to eliminate the storage speed effects.
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