A 32 bit Linux OS with PAE enabled (which is all of the current Linux distros) can actually address 64 Gb of memory, but no more than 3 Gb per process. 3 Gb may not be that much of a limitation for many processes, so large performance increases on a 64-bit system compared to a 32-bit may be difficult to observe in practice for now.
Roger Rowlett On Apr 4, 2012 5:09 AM, "Tim Gruene" <t...@shelx.uni-ac.gwdg.de> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Hi Tom, > > because there are PCs out there with more than 200GB RAM, as well as > programs and systems that make use of them. As far as I understand a > 32-bit compiled kernel would have not possibility to address anything > beyong 4GB. > > Regards, > Tim > > On 04/04/12 10:53, Tom Peat wrote: > > Hello Tim, > > > > I believe the notion comes about as one can thread 64 instead of 32 > addresses concurrently, thereby boosting performance. If it has no > performance boost, why would they bother? > > > > Cheers, tom > > > > -----Original Message----- > > From: Tim Gruene [mailto:t...@shelx.uni-ac.gwdg.de] > > Sent: Wednesday, 4 April 2012 6:43 PM > > To: Peat, Tom (CMSE, Parkville) > > Cc: CCP4BB@JISCMAIL.AC.UK > > Subject: Re: [ccp4bb] Who is using 64-bit Linux? > > > > Dear Tom, > > > > 64-bit is about memory addressing - why would you expect a performance > > boost? I have wondered where this notion originated from. > > > > Cheers, > > Tim > > > > On 04/03/12 22:07, Tom Peat wrote: > >> We use the 64 bit Centos (Red Hat) distro and CCP4, Coot, etc seem to > work fine on this. > >> I can't say I notice a big performance boost from the 64 bit side of > things. > >> Maybe I'm just impatient. > >> cheers, tom > > > > > >> Tom Peat > >> Biophysics Group > >> CSIRO, CMSE > >> 343 Royal Parade > >> Parkville, VIC, 3052 > >> +613 9662 7304 > >> +614 57 539 419 > >> tom.p...@csiro.au > >> ________________________________________ > >> From: CCP4 bulletin board [CCP4BB@JISCMAIL.AC.UK] On Behalf Of Roger > Rowlett [rrowl...@colgate.edu] > >> Sent: Wednesday, April 04, 2012 5:57 AM > >> To: CCP4BB@JISCMAIL.AC.UK > >> Subject: [ccp4bb] Who is using 64-bit Linux? > > > >> The time has come for me to upgrade my Linux OS to something more recent > >> for me and my student workstations. A 32-bit distro is certainly > >> conservative and compatible with CCP4 and Coot, but it seems like that > >> solution hobbles my hardware and puts some limitations on available > >> memory, even with PAE enabled. So who is using a 64-bit distro these > >> days, and are there lingering issues of compatibility and dependency > >> hell with commonly used XRD software, like CCP4, Coot, iMOSFLM etc.? > > > >> Ubuntu 12.04 LTS (beta) actually works OK with one simple workaround for > >> the global menu for CCP4 and Coot, and wine compatibility is fine for > >> running CrysalisPro in the same environment, so it's really comes down > >> to whether or not the extra performance of a 64-bit OS is worth the pain > >> of compatibility issues for XRD software. Any thoughts? > > > >> Cheers, > > > >> _______________________________________ > >> Roger S. Rowlett > >> Gordon & Dorothy Kline Professor > >> Department of Chemistry > >> Colgate University > >> 13 Oak Drive > >> Hamilton, NY 13346 > > > >> tel: (315)-228-7245 > >> ofc: (315)-228-7395 > >> fax: (315)-228-7935 > >> email: rrowl...@colgate.edu > > > > > > - -- > - -- > Dr Tim Gruene > Institut fuer anorganische Chemie > Tammannstr. 4 > D-37077 Goettingen > > GPG Key ID = A46BEE1A > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.12 (GNU/Linux) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ > > iD8DBQFPfA/AUxlJ7aRr7hoRAmfDAKDleNNb2BVxcNIHg7x81ks3gK5BpACgzQ9J > DwQDnMorze1xjTZ+0qqacEg= > =wVwe > -----END PGP SIGNATURE----- >