Date: Mon, 18 Jun 2007 11:08:13 -0700 From: Jeremy Chadwick <koitsu@FreeBSD.org> To: Martin Turgeon <turgeon.martin@gmail.com> Cc: freebsd-hackers@freebsd.org, freebsd-hardware@freebsd.org Subject: Re: i386 with PAE or AMD64 on PowerEdge with 4G RAM Message-ID: <20070618180813.GA13003@eos.sc1.parodius.com> In-Reply-To: <4676BAF0.4030703@gmail.com> References: <4676BAF0.4030703@gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, Jun 18, 2007 at 01:03:44PM -0400, Martin Turgeon wrote: > I just receive 2 PowerEdge servers (a 1950 and a 860) both with 4G of RAM. I > installed FreeBSD 6.2 Release i386 on both of them. Unfortunately, only 3,5G > is recognized on the 860 and 3,3G on the 1950. > dmesg on 860: > real memory = 3757834240 (3583 MB) > avail memory = 3678318592 (3507 MB) > > I am facing a difficult decision. Should I use i386 with PAE enabled in the > kernel (I read a lot of warnings using it) or should I go with AMD64? Which > branch should I follow? Based on what I've read from some of the porters and miscellaneous others, generally-speaking there's too many issues with amd64 (in the sense of 32-bit vs. 64-bit compatibility -- not the fault of the kernel or otherwise) to consider it worth switching to. I personally don't run 64-bit OSes because most developers still use 32-bit machines and don't have a way to develop/test in 64-bit environments. That said, I'd recommend you stick with i386 + PAE, simply for guaranteed application compatibility. You'll lose the amount of RAM you're seeing due to PAE addressing for PCI address space. I can dig you up a usage map (broken down by how much is taken up by each portion; PCI, ACPI, etc.) if you want one. It's for SuperMicro systems, but the general idea applies to most everything. -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20070618180813.GA13003>