[mpich-discuss] Scalability of Intel quad core (Harpertown) cluster

[Scott Atchley]

Hi Hee,

How did cactus fail when running over Open-MX?

We should probably take this off list. I have CC'd the Open-MX  
developer, Brice Goglin.

Scott

On Apr 24, 2008, at 12:45 AM, Hee Il Kim wrote:
> Thanks All,
>
> Only recently I could have a time to change the configuration of  
> switch hub and test this and that. Unfortunately, I failed to take  
> the advantage of Open-MX, which could not run Cactus benchmark for  
> some reasons.
>
> But after changing the maximum frame size to 9000 and enabling flow- 
> control, the latency could be reduced down greatly,
>
> ## mpi_pong reuslts
> ...
> ...
>
>   262144 bytes took       708 usec ( 740.412 MB/sec)
>   524288 bytes took      1500 usec ( 699.101 MB/sec)
>  1048576 bytes took      3523 usec ( 595.256 MB/sec)
>
>  Max rate = 1139.390288 MB/sec  Min latency = 2.980232 usec
>
> ##
>
> And also I could get reasonable scalability for Cactus benchmarks.  
> The MTU of the ethernet cards should be taken 1500, the default one.  
> If I increase the value, it produces worse results.
>
> In conclusion, the culprit of the scalability problem was the  
> interconnect I used, not the cpus or softwares. I appreciate all  
> your comments and suggestions.
>
> Regards,
>
> Hee Il
>