[wrfems] Old DX servers

[Tony Freeman]

Thanks Mark,

Long story short: ... didn't help. Increased runtime a little (by 5 
minutes but that's within my mental margin of error).

I believe the biggest bottleneck in this whole setup is the 800 MHz BUS 
speed.

Anyway ... Long story long:  ... I checked the BIOS for each machine and 
could not find a place to turn hyperthreading on/off ... so I updated 
the BIOS on each machine from A01 to A07.  That didn't provide a 
hyperthreading switch either but under BIOS --> CPU Info ... I could 
enable/disable 'logical processors' ... so I disabled that.  Booting up 
I found that my 4 processor machine became a 2 processor machine.  So I 
disabled 'logical processors' in all the BIOS's and made the changes in 
/usr1/wrfems/EMS.cshrc and 
/usr1/wrfems/util/benchmark/arw/conf/ems_run/run_ncpus.conf to account 
for only 2 processors on each machine. 


-- Tony


Mark.Jarvis at noaa.gov wrote:
> Tony:
>
> Your system information file shows Hyper-Threading turned ON.  That should be turned OFF.  The model does not run well with HT on.  See if you can turn that off in the BIOS and re-run the simulations.
>
> -Mark @ Louisville, KY
>
>
> ----- Original Message -----
> From: Tony Freeman <Tony.Freeman at noaa.gov>
> Date: Wednesday, December 8, 2010 4:42 pm
> Subject: Re: [wrfems] Old DX servers
> To: WRF EMS Users <wrfems at comet.ucar.edu>
>
>
>   
>> I did a few runs today to establish a baseline. Here are the benchmarks:
>>
>>     * Running the benchmark on only the one machine I call 'clusterhead'
>>       took 1 hour and 18 minutes.
>>
>>     * Running REALwrf on 'clusterhead' and ARWwrf on only the two nodes
>>       took 36 minutes 35 seconds.
>>
>>     * Running REALwrf on 'clusterhead' and ARWwrf on all machines
>>       (clusterhead, node1, node2) took 27 minutes 8 seconds.
>>
>>
>> I'm guessing that if I had a fourth machine the runtime would be 
>> quicker.  Attached is the benchmark output.
>>
>>
>> The final run_ncpus.conf file has this setup:
>>
>> REAL_NODECPUS = clusterhead:4:192.168.0.1
>> WRFM_NODECPUS = clusterhead:4:192.168.0.1,node1:4:192.168.0.43,node2:4:192.168.0.42
>>
>>
>>
>> -- Tony
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