Hello, Sorry, I didn't mention it is Redhat AS5.0 The bigsmp no longer exists. Anyone tried 32bits Redhat AS5.0 with 8G RAM for cyrus imapd? Thanks Patrick ----- Original Message ----- From: "David Carter" <dpc22@xxxxxxxxx> To: "Patrick T. Tsang" <patrick@xxxxxxxxxxxxxxxx> Cc: <info-cyrus@xxxxxxxxxxxxxxxxxxxx> Sent: Friday, July 13, 2007 5:24 PM Subject: Re: 8G RAM in 32bit platform > On Fri, 13 Jul 2007, Patrick T. Tsang wrote: > >> We will start up the mail server with 4G RAM. >> As I know the 32bits cannot handle RAM more than 3.2G. >> >> The client plans to upgrade the RAM to 8G in coming years. >> Can the 64bits platform is the only solution to it? > > You don't say which CPU or operating system you are using. > > The Linux bigsmp kernel supports PAE extensions on IA32 platforms: all 8 > GBytes will be available as buffer cache, which is what matters to Cyrus. > > 64 bit pointers don't really do anything: no single process in Cyrus needs > 2 GBytes of address space. 64 bit integer arithmetic would be a slight > benefit for quota arithmetic (unsigned long long). However my systems > spend about 2% of their time in user CPU state according to vmstat. You > really aren't going to notice on any modern Intel/AMD CPU. > > -- > David Carter Email: David.Carter@xxxxxxxxxxxxx > University Computing Service, Phone: (01223) 334502 > New Museums Site, Pembroke Street, Fax: (01223) 334679 > Cambridge UK. CB2 3QH. > ---- Cyrus Home Page: http://cyrusimap.web.cmu.edu/ Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html
