network throughput and kernel configuration...

[Alex (ander Sendzimir)]

I've been experimenting with kernel configurations and network 
performance. I'm running a dual Xeon processor (500MHz) system with 
10/100 ethernet (Intel). It's an Intel motherboard. The cable is CAT5 
and I'm transferring between the FBSD box and an Apple G4 laptop with 
10/100 ethernet. This is going through a Netgear 10/100 hub (non 
switching). In my limited capacity I'm using ncftp{put/get} to transfer 
large files. Using a basic, no frills custom kernel (nothing 
controversial), ncftp shows about 7.5MB/s throughput between these two 
machines. I added the following lines to my kernel conf

	options DEVICE_POLLING
	options HZ=1000

and modified /etc/sysctl.conf by adding

	kern.polling.enable=1

and now ncftp shows about 8 MB/s. (Recompile, reboot, etc)

Perhaps I'm dreaming, but shouldn't I be getting better network 
throughput in either case? Perhaps a switch would be better than a hub?

The G4 Powerbook shows its running en0 at half-duplex over 100baseTX. 
Which, I think, is the same for the dual Xeon system. Both are 
autoselect. Perhaps I should scrap the kernel config issue and 
configure both interfaces for full-duplex 100baseTX.

Thoughts/experience/advice?

Thanks for the help, as always.

Alex

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Alexander Sendzimir                             802 863 5502
  Mac Tutor of Vermont, LLC         info @ mactutor . vt . us
   Colchester, VT 05446