Re: OT: Maximum number of fast ethernet cards
- From: Ron Johnson <ron.l.johnson@xxxxxxx>
- Date: Fri, 16 Jun 2006 19:36:24 -0500
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Pete Clarke wrote:
Hi there,
This is slightly offtopic, but does anyone know the maximum
number of fast ethernet cards a typical PC can handle..? I want
to use a cheap (ish) Debian box as a firewall/router to
suppliment my Netgear, and provide more services to the internal
network than currently available.
Like what?
With this in mind, I was intending on slapping a load of dual
portal network cards into a redundant PC. I remember reading a
while back that the ultimate limit will be the PCI bus bandwidth
- with this in mind, what would be the maximum number of NIC's I
could realistically install into a PC?
That's right. A bus can't carry more than the bus can carry...
For bog-standard 33MHz/32bit PCI, that's 133MBps theoretical which
is shared with the IDE controller.
Fast Ethernet is 100Mbps == 12.5MBps, which means you could
supposedly fit in 10 FastE *ports* before flooding the bus. But
this will only give you enough extra bandwidth to write log files
out to disk.
Since no one ever gets the theoretical maximum, lets drop that down
20% to 8 ports. Which means 4 dual-port cards. Doesn't look like a
problem for a full-sized ATX mobo. But then, when have you ever
seen Ethernet running a full capacity? So, 10 ports *may* work.
I'd stick with 8 ports, though.
PCI-x cards (64 bit and/or 66MHz) will arithmetically increase the
bandwidth. Don't know the bandwidth of PCI-e, but you can find it
in Wikipedia and do the math (sums? reckoning?) yourself.
Regarding CPU, modern CPUs are *fast* in text-only mode. No,
*stupendously* fast. A Pentium 90 *should* be able to handle that
much data.
The *definite* problem I foresee is interrupts. Every 1500 byte
packet generates a hard interrupt, so that's a theoretical max of
8738 hard interrupts per port. With 8 ports, that's 70,000 hi's per
second. Can the Linux kernel handle that on a given bit of HW?
You've just flown beyond my area of expertise...
- --
Ron Johnson, Jr.
Jefferson LA USA
Is "common sense" really valid?
For example, it is "common sense" to white-power racists that
whites are superior to blacks, and that those with brown skins
are mud people.
However, that "common sense" is obviously wrong.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.3 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
iD4DBQFEk06IS9HxQb37XmcRAk39AJ9VNRuKbyuf098S/FEhDnjNH+7gWwCYu9eb
O6ZlYnbuoT+f6xUyWTBf/g==
=olh9
-----END PGP SIGNATURE-----
--
To UNSUBSCRIBE, email to debian-user-REQUEST@xxxxxxxxxxxxxxxx
with a subject of "unsubscribe". Trouble? Contact listmaster@xxxxxxxxxxxxxxxx
- References:
- OT: Maximum number of fast ethernet cards
- From: Pete Clarke
- OT: Maximum number of fast ethernet cards
- Prev by Date: Re: Installation failure using debian-31r2-i386-binary-1.iso
- Next by Date: How do I access a forwarded port on Box A from Box B?
- Previous by thread: OT: Maximum number of fast ethernet cards
- Next by thread: Re: OT: Maximum number of fast ethernet cards
- Index(es):
Relevant Pages
|
