From bernard at blackham.com.au Fri Mar 11 11:38:13 2005 From: bernard at blackham.com.au (bernard@blackham.com.au) Date: Fri Mar 11 11:38:28 2005 Subject: [Wizard] Fwd: [PATCH] Support for GEODE CPUs Message-ID: <20050311033813.GA11589@ucc.gu.uwa.edu.au> Breaking the silence... This cropped up on lkml and seemed quite relevant so I thought I'd pass it along here for anybody who might be interested. ----- Forwarded message from Alan Cox ----- Subject: Re: [PATCH] Support for GEODE CPUs From: Alan Cox On Mer, 2005-03-09 at 17:33, Lennart Sorensen wrote: > Alan Cox wrotes: > > a) "Geode" (Geode GX) runs -m486 code faster than -m586 > > Now if the Geode GX1 in fact runs faster optimized for 486 rather than > 586 (I have been running one as 586tsc since it had mmx and tsc in its > feature list), then I think I will be recompiling my kernel to see if I > can't make this 266MHz GX1 run almost as fast as a 400MHz PXA255 (arm). > Right now it has somewhat lower ethernet bandwidth than the arm. If you build 486 it will still use the TSC because it is available (The PIT is buggy but the kernel knows about that anyway and handles it). There are a few Geode tricks to know for performance - Turn off the video - If you can't turn it off use solid areas of colour to speed the system up (The hardware uses RLE encoding to reduce ram fetch bandwidth) - Remember the cache is only 16K (12K when running X11 as 4K is borrowed for the blitter) - The onboard audio is a software SB emulation on older GX. It burns CPU. Also avoid touching various legacy registers as much as possible, many cause BIOS traps in SMM emulation code. The list I have is NDA but you can use rdtsc/inb or outb/rdtsc to work out which 8) Alan ----- End forwarded message ----- From quozl at us.netrek.org Fri Mar 11 13:34:04 2005 From: quozl at us.netrek.org (James Cameron) Date: Fri Mar 11 13:33:37 2005 Subject: [Wizard] Fwd: [PATCH] Support for GEODE CPUs In-Reply-To: <20050311033813.GA11589@ucc.gu.uwa.edu.au> References: <20050311033813.GA11589@ucc.gu.uwa.edu.au> Message-ID: <20050311053404.GA28051@us.netrek.org> Indeed, very relevant. Alan Cox wrote: > - The onboard audio is a software SB emulation on older GX. It burns > CPU. Found mine certainly got warm playing audio. This explains it. I don't bother asking it to do that any longer. -- James Cameron mailto:quozl@us.netrek.org http://quozl.netrek.org/ From adrian at ucc.gu.uwa.edu.au Fri Mar 11 13:46:11 2005 From: adrian at ucc.gu.uwa.edu.au (Adrian Chadd) Date: Fri Mar 11 13:46:17 2005 Subject: [Wizard] Fwd: [PATCH] Support for GEODE CPUs In-Reply-To: <20050311053404.GA28051@us.netrek.org> References: <20050311033813.GA11589@ucc.gu.uwa.edu.au> <20050311053404.GA28051@us.netrek.org> Message-ID: <20050311054611.GA22787@ucc.gu.uwa.edu.au> On Fri, Mar 11, 2005, James Cameron wrote: > Indeed, very relevant. > > Alan Cox wrote: > > - The onboard audio is a software SB emulation on older GX. It burns > > CPU. > > Found mine certainly got warm playing audio. This explains it. I don't > bother asking it to do that any longer. Can you do audio on them without going through the SB layer?