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

Ben Scott dragonhawk at gmail.com
Thu Jun 14 16:15:57 EDT 2007


On 6/14/07, Jeff Macdonald <macfisherman at gmail.com> wrote:
>> What can you reasonably expect a pci gigabit card to give you for
>> through put?
>
> I thought I read somewhere gig ether should be on the motherboard, not PCI.

  Many modern motherboards do include one or more gig Ether ports.
Sometimes, these are just connected to internal PCI buses.  Sometimes,
they're even all on the same PCI bus.  Sometimes they use internal PCI
Express ports.  Sometimes they hook directly into a special path on
one of the core chips.  You can get varying levels of performance
here, depending on the specifics.

  There's PCI in multiple flavors (32-bit vs 64-bit, 33 MHz vs 66
MHz), PCI-X (some sort of extension to the classic PCI bus), and PCI
Express (totally different electrically; serial rather than parallel).

  I do agree with Patrick Flaherty and Tom Buskey that the NIC may not
be the constraint (although a cheap chipset can certainly kill your
performance).  You need to worry about bus bandwidth (for NIC and disk
controller), disks, disk controller, core logic, IP stack, application
software, kernel tuning, and sometimes even RAM and CPU (depending on
the workload).  And you need to worry about that on both computers.

  Cable and switch quality can also matter, too.  A bad cable can
cause all manner of problems.  And I've heard of cheap gig switches
which couldn't actually forward data that fast.

-- Ben


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