Re: The ultimate TOE design

[Joel Jaeggli <joelja@xxxxxxxxxxxxxxxxxxxx>]

On Wed, 15 Sep 2004, David Stevens wrote:

> I've never understood why people are so interested in off-loading
> networking. Isn't that just a multi-processor system where you can't
> use any of the network processor cycles for anything else? And, of
> course, to be cheap, the network processor will be slower, and much
> harder to debug and update software.

I's like to amplify this, adding more general purpose cpu to a machine 
strikes me as the right design choice since they're simply more generally 
useful than dedicated cpu's. look at linux software raid compared to the 
alternatives, frankly I haven't seen a hardware controller that can touch 
it for performance given a similar number of disks and interfaces... 
Currently graphcas card have substantionaly more memory bandwidth and 
pipelines than most general purpose cpu's but eventually that won't be the 
case. as it is gpus still represent the biggest chunk of independat 
computational power in a and at least on the server side we don't even 
use them.

> If the PCI bus is too slow, or MTU's too small, wouldn't
> it be better to fix those directly and use a fast host processor that can
> also do other things when not needed for networking? And why have
> memory on a NIC that can't be used by other things?

Between hyper-transport tunnels, pci-x, pci-express and infinband, the 
bottlnecks between the cpu core and the perhiperals and memory are falling 
away at a rapid clip even as cpu's get faster. we're in a much better 
position to build balanced systems then we were 2 years ago.

> Why don't we off-load filesystems to disks instead?  Or a graphics
> card that implements X ? :-) I'd rather have shared system resources--
> more flexible. :-)
>
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Joel Jaeggli  	       Unix Consulting 	       joelja@xxxxxxxxxxxxxxxxxxxx 
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