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From: Pavel Shamis (Pasha) (pasha_at_[hidden])
Date: 2007-08-13 11:52:06


George Bosilca wrote:
>
> On Aug 13, 2007, at 11:28 AM, Pavel Shamis (Pasha) wrote:
>
>> Jeff Squyres wrote:
>>> I guess reading the graph that Pasha sent is difficult; Pasha -- can
>>> you send the actual numbers?
>>>
>> Ok here is the numbers on my machines:
>> 0 bytes
>> mvapich with header caching: 1.56
>> mvapich without header caching: 1.79
>> ompi 1.2: 1.59
>>
>> So on zero bytes ompi not so bad. Also we can see that header caching
>> decrease the mvapich latency on 0.23
>>
>> 1 bytes
>> mvapich with header caching: 1.58
>> mvapich without header caching: 1.83
>> ompi 1.2: 1.73
>>
>> And here ompi make some latency jump.
>>
>> In mvapich the header caching decrease the header size from 56bytes to
>> 12bytes.
>> What is the header size (pml + btl) in ompi ?
>
> The match header size is 16 bytes, so it looks like ours is already
> optimized ...
So for 0 bytes message we are sending only 16bytes on the wire , is it
correct ?

Pasha.
>
> george.
>
>>
>> Pasha
>> _______________________________________________
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>
>