Re: How fast can linux do serial I/O to a Z8530

Alan Cox (
Sun, 22 Jun 1997 00:18:54 +0100 (BST)

> How fast can the current kernels cope with serial I/O from devices
> with small FIFOs - I'm thinking specifically of a Z8530 which has a 3
> character ring buffer.

The good Z8530's have 8 characters upwards.

> I ask because I have a need to route IP packets comming in over three
> 64Kbps synchronous serial links to a LAN. One option is to use a
> couple of z8530 cards and write a linux driver for them (probably
> based on the old kiss tnc driver). Na=EFvely this seems to imply
> handling 24,000 interrupts per second which seems a tall order on its

It should survive ok IF you aren't using IDE drives. You'll probably
drop the odd byte, but not enough to matter. For reference I can do
38,400 solidly on a Z8530 on a Sun Sparc IPC (low end 486 speed),
but cant get 64K sync to work