[Asterisk-Dev] G.729 MIPS calculation

[Steve Underwood]

Hi,

MIPs is not always a very meaningful figure with processors like a 
Pentium. Cache pressure can have a huge impact. The figure ot 80-100MIPs 
per instance suggests a 3GHz Pentium will do far more than an E1. When I 
tested by running many instances of the IPP G.729 I think I had about 40 
per processor, doing nothing by G.729 coding of audio buffered memory.

The ratio of 6:1 you quote for compression:decompression time sounds a 
bit high. 4:1 or 5:1 sounds more likely. I doubt the measurement 
accuracy of that recalc is very good.

Regards,
Steve


Daniel Pocock wrote:

>
> I just tried the IPP stuff on a HP DL140, dual 3.0GHz, the codec 
> compile is optimized for Xeon and statically linked.
>
> 'show translation recalc 200' showed me that compress from slinear to 
> G729 was 6ms and decompress was 1ms or less.
> That's a total of 7ms to handle 1000ms of audio full duplex.
>
> Does that mean that 1000ms / 7ms = 142 is the number of channels this 
> server could handle simultaneously, or is there other overhead to 
> consider?
>
>
>
>
>
> Steve Underwood wrote:
>
>> Miroslav Nachev wrote:
>>
>>>   Hi,
>>>
>>>   I would like to meter the MIPS for G.729 implementation using Intel
>>> IPP. Can you help me how to do that?
>>>  
>>>   Best Regards,
>>>   Miroslav Nachev
>>>  
>>>
>> For 1 Rx channel + 1 Tx channel, G.729 typically takes 10 to 20MIPs 
>> on a DSP, depending how you count MIPs, and what the DSP chip is. It 
>> typically takes 80 to 100MIPs on a Pentium, depending on the 
>> implementation. The IPP stuff doesn't make a huge difference, as it 
>> doesn't seem to speed things up a great deal. On a 3GHz Pentium you 
>> can typically run about an E1's worth of G.729 channels. A really 
>> efficient version might get you to 2 E1s, but I haven't seem one that 
>> quite gets that far.
>