32 or 64 bit and ifort?
Bjarne Büchmann
Just a quick question/poll (as we are building a new cluster and making key decisions _very_ soon).
How many run on Intel-based systems with 64 bit linux OS (and use the ifort compiler)?
How is your experience with it?
We would (in principle) like to move to 64bit, but I am not sure if we will get any significant advantage(?)
(I know the 4GB memory per job limit, but we will probably not hit that).
MED VENLIG HILSEN / BEST REGARDS
BJARNE BÜCHMANN
CIVILINGENIØR, PhD
OVERGADEN OVEN VANDET 62 B · POSTBOKS 1919
DK - 1023 KØBENHAVN K
TLF. +45 3268 9697
FAX +45 3257 4341
MOBIL +45 3268 9736
B...@FRV.DK · WWW.FRV.DK
I forbindelse med den nye regerings tiltræden er det besluttet, at Farvandsvæsenet nedlægges og splittes op mellem fire forskellige ministerier. Læs mere på Farvandsvæsenets hjemmeside
The new Danish government has decided to close the Danish Maritime Safety Administration and transfer responsibility for some of its activities from the Ministry of Defence to other ministries. Read more at DaMSA´s website
Karsten Bolding
I've not experienced any problems in running 64 bit on my work computer.
ifort is the smallest issue as it has been supported for a long time -
but also all python related packages works without a glitch (Ubuntu that
is - maybe different if you go to RHEL or Suse).
On the other hand I've yet experienced any big advantages.
Karsten
On Wed, Nov 30, 2011 at 01:49:21 +0100, Bjarne B�chmann wrote:
> Dear Users,
>
> Just a quick question/poll (as we are building a new cluster and making key decisions _very_ soon).
>
> How many run on Intel-based systems with 64 bit linux OS (and use the ifort compiler)?
> How is your experience with it?
>
> We would (in principle) like to move to 64bit, but I am not sure if we will get any significant advantage(?)
>
> (I know the 4GB memory per job limit, but we will probably not hit that).
>
>
> �MED VENLIG HILSEN / BEST REGARDS
> �
> �
> BJARNE B�CHMANN
> �CIVILINGENI�R, PhD
>
> �
> �OVERGADEN OVEN VANDET 62 B � POSTBOKS 1919
> �DK - 1023 K�BENHAVN K
> �TLF. +45 3268 9697
> �FAX +45 3257 4341
> �MOBIL +45 3268 9736
> �B...@FRV.DK � WWW.FRV.DK
>
> I forbindelse med den nye regerings tiltr�den er det besluttet, at Farvandsv�senet nedl�gges og splittes op mellem fire forskellige ministerier. L�s mere p� Farvandsv�senets hjemmeside
>
> The new Danish government has decided to close the Danish Maritime Safety Administration and transfer responsibility for some of its activities from the Ministry of Defence to�other ministries. Read more at DaMSA�s website �
>
>
adolf...@jrc.ec.europa.eu
we changed about 2006 to 64 bit and experienced very little problems.
We use/used ifort and SUSE, openmpi.
At that time I was impressed by the speed gain we got.
We could compare a simple run of a test case (e.g seamount) so you might get an idea.
I would not even consider to think about 32bit technology anymore, that is technological out
(even personally I do not have any 32 bit technology anymore).
Regards, Adolf
Tiago Silva (Cefas)
We recently moved to 64 bit and still have two identical cluster head
nodes, one with 32 bit and another one with 64 bit.
On moving to 64 bit we noticed an improvement in performance, maybe
10-20% I don't remember exactly. After reading about this I attributed
it to doing without the memory paging but the comparison wasn't thorough
as many libraries were different. No disadvantages with 64 bit so far.
We have ifort 11 and RH 5.3.
Tiago
Karsten Bolding
I've actually experienced a - yet unsolved - problem with 64 bit. I
experienced performance problems with GOTM cases and it boiled down to
NetCDF. When I ran with NetCDF4 I only got 50-60% on a CPU-core. When I
disabled saving I got 100%. Re-compiling with NetCDF 3.6.3 and
re-anabling saving I got my 100% again. This was done on 32 bit.
Now I've tried to get NetCDF 3.6.3 installed on a pure 64 bit machine
and I run into compilation problems related to -fPIC. Don't know if
-fPIC is mandatory on 64 bit machines - but the fortran compiler (ifort
v. 11) doesn't like it.
Karsten
On Wed, Nov 30, 2011 at 01:49:21 +0100, Bjarne B�chmann wrote:
> Dear Users,
>
> Just a quick question/poll (as we are building a new cluster and making key decisions _very_ soon).
>
> How many run on Intel-based systems with 64 bit linux OS (and use the ifort compiler)?
> How is your experience with it?
>
> We would (in principle) like to move to 64bit, but I am not sure if we will get any significant advantage(?)
>
> (I know the 4GB memory per job limit, but we will probably not hit that).
>
>
> �MED VENLIG HILSEN / BEST REGARDS
> �
> �
> BJARNE B�CHMANN
> �CIVILINGENI�R, PhD
>
> �
> �OVERGADEN OVEN VANDET 62 B � POSTBOKS 1919
> �DK - 1023 K�BENHAVN K
> �TLF. +45 3268 9697
> �FAX +45 3257 4341
> �MOBIL +45 3268 9736
> �B...@FRV.DK � WWW.FRV.DK
>
> I forbindelse med den nye regerings tiltr�den er det besluttet, at Farvandsv�senet nedl�gges og splittes op mellem fire forskellige ministerier. L�s mere p� Farvandsv�senets hjemmeside
>
> The new Danish government has decided to close the Danish Maritime Safety Administration and transfer responsibility for some of its activities from the Ministry of Defence to�other ministries. Read more at DaMSA�s website �
>
>
Johan Van Der Molen (Cefas)
for what it's worth, I've done a test on our system (64 bit, Netcdf 4 with HDF, IFORT11), and I get nearly 100% cpu time (while saving files), see below.
Having said that, we use an older version of GOTM coupled with ERSEM and an SPM module.
[jv02@deepblue src]$ top
top - 09:09:32 up 68 days, 2:17, 60 users, load average: 2.89, 2.54, 2.31
Tasks: 707 total, 4 running, 702 sleeping, 1 stopped, 0 zombie
Cpu(s): 14.3%us, 4.6%sy, 0.0%ni, 81.0%id, 0.0%wa, 0.0%hi, 0.1%si, 0.0%st
Mem: 65981408k total, 65675236k used, 306172k free, 330104k buffers
Swap: 1020116k total, 49224k used, 970892k free, 55043424k cached
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
24715 cc06 25 0 5046m 4.7g 8684 R 100.2 7.4 2853:57 test_tidal_anal
2363 jv02 25 0 1728m 1.4g 9.8m R 99.9 2.3 9894:59 make_particle_m
7125 jv02 25 0 77652 9600 5656 R 99.5 0.0 1:00.06 gotm
1657 jv02 15 0 107m 57m 7652 S 1.0 0.1 1:49.95 nxagent
Johan
> -----Original Message-----
> From: getm-...@googlegroups.com [mailto:getm-...@googlegroups.com]
> On Behalf Of Karsten Bolding
> Sent: Wednesday, December 21, 2011 6:02 AM
> To: getm-...@googlegroups.com
> Subject: Re: [getm-users: 1553] 32 or 64 bit and ifort?
>
> a short update ....
>
> I've actually experienced a - yet unsolved - problem with 64 bit. I
> experienced performance problems with GOTM cases and it boiled down to
> NetCDF. When I ran with NetCDF4 I only got 50-60% on a CPU-core. When I
> disabled saving I got 100%. Re-compiling with NetCDF 3.6.3 and
> re-anabling saving I got my 100% again. This was done on 32 bit.
>
> Now I've tried to get NetCDF 3.6.3 installed on a pure 64 bit machine
> and I run into compilation problems related to -fPIC. Don't know if
> -fPIC is mandatory on 64 bit machines - but the fortran compiler (ifort
> v. 11) doesn't like it.
>
> Karsten
>
> > Dear Users,
> >
> > Just a quick question/poll (as we are building a new cluster and
> making key decisions _very_ soon).
> >
> > How many run on Intel-based systems with 64 bit linux OS (and use the
> ifort compiler)?
> > How is your experience with it?
> >
> > We would (in principle) like to move to 64bit, but I am not sure if
> we will get any significant advantage(?)
> >
> > (I know the 4GB memory per job limit, but we will probably not hit
> that).
> >
> >
> > MED VENLIG HILSEN / BEST REGARDS
> >
> >
> > CIVILINGENIØR, PhD
> >
> >
> > OVERGADEN OVEN VANDET 62 B · POSTBOKS 1919
> > TLF. +45 3268 9697
> > FAX +45 3257 4341
> > MOBIL +45 3268 9736
> > B...@FRV.DK · WWW.FRV.DK
> >
> ministerier. Læs mere på Farvandsvæsenets hjemmeside
> >
> > The new Danish government has decided to close the Danish Maritime
> Safety Administration and transfer responsibility for some of its
> activities from the Ministry of Defence to other ministries. Read more
> at DaMSA´s website
> >
> >
>
> --
> http://www.getm.eu