Date: Thu, 30 Aug 2007 20:31:57 -0700 From: Garrett Cooper <youshi10@u.washington.edu> To: User Bobby <bobby@susanne.tomatoseed.org>, FreeBSD Questions <freebsd-questions@freebsd.org> Subject: Re: 4gb address space limitation for i386 Message-ID: <46D78BAD.8070502@u.washington.edu> In-Reply-To: <20070830205618.Q11358@susanne.tomatoseed.org> References: <Pine.LNX.4.43.0708301753260.22678@hymn08.u.washington.edu> <20070830205618.Q11358@susanne.tomatoseed.org>
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User Bobby wrote: > Ok thank you all for your replies. > > I'm thinking I can't use amd64 on a PIII, right? > > So, given that I'm stuck with this particular piece of hardware, my > only real option is to begin down the long and scary road of PAE. Yes? > > Bob > > On Thu, 30 Aug 2007, youshi10@u.washington.edu wrote: > >> On Thu, 30 Aug 2007, User Bobby wrote: >> >>> I have an IBM xSeries 350 4xPIII with 5.5gb of RAM, and see that >>> only about 3.5gb is being used under the i386 port. I've been >>> looking through the >>> archives to try and figure out what the root of the problem is and I >>> amn't >>> quite sure I know which part of the situation is the real problem. >>> >>> Is it a limitation of the i386 port? That is to say, if there were >>> a specific PIII (i686?) port, would this problem be overcome? Or is >>> it a hardware limitation? Is it necessary to use a not-clean method >>> to access the extra address space (is this what PAE is?), and >>> there's no clean >>> way around it, regardless of the port? >>> >>> I was looking at building a PAE kernel, but was discouraged by the >>> lack of usb and certain SCSI support, both of which I'd really like >>> to have (in the case of SCSI, need to have). Is this lack of >>> support because of an inherent difficulty in the hardware, or could >>> it be overcome in a stable way with modification of the device >>> driver code? >>> >>> My basic (and very hypothetical) question - if I had unlimited time >>> and knowledge (I have limited both), what direction would I take to >>> get access to all 5.5gb of RAM on this particular computer? >>> >>> Thank you, >>> Bob >> >> It's a limitation of the basic i386 architecture; you have to use >> i386 with PAE, or better yet use amd64, because those architectures >> support memory address sizes beyond 32-bits. >> >> Cheers, >> -Garrett Correct. -Garrett
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