Re: PCMCIA GigE adapters with jumbo frames
- From: Rick Jones <rick.jones2@xxxxxx>
- Date: Wed, 15 Feb 2006 23:26:03 GMT
Scott W Gifford <gifford@xxxxxxxxx> wrote:
There is no network yet; I'm giving general advice to somebody
building a new SOHO-sized GigE network. I'm primarily a Unix server
guy, so I'm kind of winging it in the network department. :-)
No problem, I'm winging it in the PCMCIA department. I don't suppose
the PCMCIA card vendors say which chips are in their PCMCIA cards do
they? You could compare with PCI/PCIX cards and see if it might be a
feature that is likely there but not touted or whatnot. Just a wild
guess.
Have you tried emailing any of the PCMCIA GigE card vendors?
From what I saw looking around, it looked like the extra cost to
support jumbo frames was quite small for other devices (such as
switches and PCI cards), and numerous benchmarks showed a performance
and CPU utilization improvement. So, it seems sensible to buy a
PCMCIA card with jumbo frame support, as long as one is available and
the cost isn't too high. We can experiment afterwards to see if it
makes a difference or not. On the other hand, if the cards aren't
available or are very expensive, we can certainly live without it.
Another feature you might look for is "TSO" or "large send" support.
It is akin to a "poor man's" Jumbo Frame - the sending TCP stack can
give large TCP segments to the NIC, which then resegments them into
"real" MSS sized segments and spits them onto the wire. Does not
require JF support in the receivers or switches - of course it then
only really benefits the sender.
It does presuppose support for checksum offload, which if you _are_
going to use JumboFrame, while not required would be very nice because
JumboFrame for a bulk transfer will basically cut the number of
packets and so the "per packet" costs, but will leave the per-byte
costs in place so things become more dominated by the per-byte costs.
CKO addresses per-byte costs.
rick jones
--
portable adj, code that compiles under more than one compiler
these opinions are mine, all mine; HP might not want them anyway... :)
feel free to post, OR email to rick.jones2 in hp.com but NOT BOTH...
.
- References:
- PCMCIA GigE adapters with jumbo frames
- From: Scott W Gifford
- Re: PCMCIA GigE adapters with jumbo frames
- From: Rick Jones
- Re: PCMCIA GigE adapters with jumbo frames
- From: Scott W Gifford
- Re: PCMCIA GigE adapters with jumbo frames
- From: Rick Jones
- Re: PCMCIA GigE adapters with jumbo frames
- From: Scott W Gifford
- PCMCIA GigE adapters with jumbo frames
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