[Asterisk-Users] How many TDM2400P's will a server take?

[Matthew Fredrickson]

On Jan 30, 2006, at 4:16 PM, James Harper wrote:

>> Juan Carlos Castro y Castro wrote:
>>> How many TDM2400P cards can I safelly install in one PC? I'm loking
> for
>>> answers from whoever has a working scenario with * and a number of
> cards
>>> higher than one.
>>
>>
>> Depends on the specs of the server. For example, a quad Xeon will be
>> able to service many more interrupts/card/channels than a 500 mHz
>> Celeron. :-)
>>
>
> Given that one TDM2400P (or even the old 4 port one) generates 1000
> interrupts/second, do two cards together have to generate 2000
> interrupts/second? Is there, or could there be, a way to synchronise
> them so that both cards can be serviced by the one interrupt.
>
> Or is it more the work that needs to be done per interrupt rather than
> the number of interrupts that is the problem?

Exactly... you're getting it.  Doing 1000 things a second is not a lot 
of things to do for a processor that's clocked at 2,000,000,000 hertz  
(2 billion somethings per second :-) ).  It's more of what has to occur 
during the interrupt handler that causes problems.  The TDM2400P 
busmasters just about everything (including commands to registers and 
such) so it doesn't have to spend a lot of time in the interrupt 
handler waiting for PCI accesses.  Your biggest problem that you'll 
probably worry about is power consumption and heat generation in worst 
case ringing scenario, as someone else mentioned.

Matthew Fredrickson