Re: New gigabit cards

[Jeff Garzik]

Scott Laird wrote:
> According to the drivers, the 1000TPC uses the NS DP83820.  According to
> the DP83820's datasheet, it has a 8k Tx buffer and a 32k Rx buffer.
> That's a bit shy of the 512k-1M that older cards use :-(.  At wire speed,
> that means that you'll have to service the NIC's interrupt within ~60 us
> on transmit and ~250 us on receive.  That seems rather optimistic.

Are you assuming one interrupt per packet?

GigE drivers employ interrupt mitigation, large rings, and sometimes
resort to polling instead of servicing interrupts, and other
techniques.  Tiny buffers are ugly, but you can deal with them...

-- 
Jeff Garzik       | May you have warm words on a cold evening,
Building 1024     | a full moon on a dark night,
MandrakeSoft      | and a smooth road all the way to your door.