I have been doing some experiments with runnign 32 bit processed on and amd64 kernel over the last couple of days and am wondering what the general feel is for the best way to use over 4 gigs of memory. As far as I can see I have 3 options: 1) amd64 kernel + 64 bit processes 2) amd64 kernel + 32 bit processes 3) i386 kernel with PAE and 32 bit processes I was initially thinking that option 1 was the best, but benchmarking it the programs take 3 times longer to run that option 2! This astounds me and I intend to investigate why, but given it is rue then that rules it out as a viable solution for deploying stuff. Which leaves either 32 bit processes on a 64 bit kernel or alternatively running under PAE on a 32 bit kerenel. I don't know a lot about PAE and was wondering if anyone had any advice either way as to which wouldbe the most stable and/or best performing. cheers, -pcf.
> 1) amd64 kernel + 64 bit processes > 2) amd64 kernel + 32 bit processes > 3) i386 kernel with PAE and 32 bit processes > > I was initially thinking that option 1 was the best, but benchmarking it > the programs take 3 times longer to run that option 2! This astounds me > and I intend to investigate why, but given it is rue then that rules it out > as a viable solution for deploying stuff.How did you benchmark? Maby there are some hints on tune/optimize? -- regards Claus When lenity and cruelty play for a kingdom, the gentlest gamester is the soonest winner. Shakespeare
Hi, On 4 Nov 2007, at 21:11, Pete French wrote:> I have been doing some experiments with runnign 32 bit processed on > and amd64 kernel over the last couple of days and am wondering what > the general feel is for the best way to use over 4 gigs of memory. > As far > as I can see I have 3 options: > > 1) amd64 kernel + 64 bit processes > 2) amd64 kernel + 32 bit processes > 3) i386 kernel with PAE and 32 bit processes > > I was initially thinking that option 1 was the best, but > benchmarking it > the programs take 3 times longer to run that option 2! This > astounds me > and I intend to investigate why, but given it is rue then that > rules it out > as a viable solution for deploying stuff.I had similar results, I surmise (without evidence) it's to do with cache usage.> Which leaves either 32 bit processes on a 64 bit kernel or > alternatively > running under PAE on a 32 bit kerenel. I don't know a lot about PAE > and > was wondering if anyone had any advice either way as to which > wouldbe the most > stable and/or best performing.If your workload is CPU-intensive it probably doesn't matter; if it isn't, I'd do some more experiments.> cheers, > > -pcf.-- Bob Bishop +44 (0)118 940 1243 rb@gid.co.uk fax +44 (0)118 940 1295