polling(4) and Gigabit

[Tony Sarendal]

Luigi Rizzo wrote:
> On Sun, May 18, 2003 at 09:53:26AM +0200, Tony Sarendal wrote:
> 
>> From what I can see nge is the only polling driver for
>>Gig NICs, looking at 4.8. Has anyone done any performance
> 
> 
> actually that would be 'em'
> 

The nge driver looked like it had it, and 4.8 release notes:
The nge(4) driver now supports network device  polling(4).

I couldn't find it in any other driver, but Mike T. pointed
out that I should look at STABLE. I'll do that.

> 
>>tests on this ? I'm interested in knowing what can of
>>bandwidth/pps one actually can achieve on a PC router.
> 
> 
> it depends on a lot of factors including the size of the routing
> table, the firewall ruleset complexity, the bus speed, the CPU
> speed, the packet sizes.
> 

Since I'm coming from Ciscoland I can buy the fattest PC on the
block and still think it's a steal.

> With a fast enough box (2.4GHz) i reached some 650-700kpps through
> a FreeBSD box running 4.7 and configured as a bridge, similar
> thing with a router and fastforwarding. If you use the firewall, you
> could get down to some 400-500kpps at best. This is with 64-byte
> packets. In terms of bandwidth, with large enough frames (i'd
> say 500+ bytes) you should have no trouble running close
> to wire speed (again, depending on the above factors).
> 
> 

650-700kpps on a 2.4GHz, that's awesome, what was the limitation ? CPU ?

Do you know how much $ I have to spend to buy a Cisco which can match
that in reality ? I can tell you, a lot !

Besides, Cisco counts one packet through the router as two packets.
That makes it 1.3-1.4Mpps. After that the marketing department enters
and makes it 3Mpps.

>>If the NIC now is the limitation(?), how much OS resources
>>do I have left after the NIC is running at 100% ?
> 
> 
> the NIC is not always the limitation, you can run out of
> steam on many parts of the system.
> 

Faster PC's come along a lot more often than faster routers,
or even faster NICs, if the NIC isn't the limitation but the
CPU then more speed is on the way.

/Tony