At Thu, 14 Dec 2006 15:09:37 -0800, Andrew Laurence wrote: > > I've seen occasional conversation here regarding running Cyrus in > 64-bit mode, The use of the phrase "64-bit mode" implies restricting the converstation to those architectures which have the ability to support different modes of execution, e.g. the UltraSPARC and AMD64 CPUs. :-) > but is there an advantage aside from very large quotas? Unless your C compiler is in the dark ages there shouldn't be any need to run on a 64-bit CPU just to be able to use 64-bit integers such as those used for large quotas. > Is Cyrus known to run faster in 64-bit, for instance? Well that depends on what your definitino of "faster" is. In one environment I support it would be impossible to manage the same user load on a machine without more than 4GB of RAM and so without running it on a true 64-bit platform with more than 32-bit direct addressing (we use an AlphaServer ES40 with 16GB of RAM and four processors) the speed would be "infinitely" slow, i.e. it wouldn't run at all. I.e. there's usually a lot more to a _system_ than just a single instance of a program running on a given processor. FYI the Alpha CPU, with the right associated machine architecture, runs applications quite well -- i.e. with comparable and sometimes better performance than, say, 32-bit Intel CPUs of the same generation, and to the best of my knowledge the Alpha only supports 64-bit execution. Often applications running on an Alpha will require more RAM, but usually the memory and cache architecture are designed in such a way that this doesn't adversely affect their performance. I'd venture to guess that the same can be said of an AMD64 (in 64-bit mode), as well as the newer 64-bit SPARC machines (again, in 64-bit mode). -- Greg A. Woods H:+1 416 218-0098 W:+1 416 489-5852 x122 VE3TCP RoboHack <woods@xxxxxxxxxxx> Planix, Inc. <woods@xxxxxxxxxx> Secrets of the Weird <woods@xxxxxxxxx> ---- 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
