PAE Slowdown

[LI Xin]

Jeff Kramer wrote:
> Hey all,
> 
> I know that AMD64's the preferred way to run >4 gig systems, but I'm
> having a weird situation with 6.2-RELEASE-p8 and 6-STABLE as of last
> night.  When I compile the PAE kernel, my system performance drops like
> a rock.  It still boots and everything still runs, but for instance,
> running the Flops port my megaflops drop from the 950 MFLOPS range to 4
> MFLOPS.  It feels about as fast as a 486.
> 
> I'm not sure what I should try disabling.  I tried nodevice usb, but
> that didn't seem to change anything.  SMP and GENERIC kernels work fine.
> 
> CPU: Intel Core Duo 2 Quad 2.4ghz
> Memory: 8 gig (4 2 gig dimms)
> Swap: 16 gig partition
> 
> If I try to boot without ACPI disabled the kernel doesn't finish
> booting, it stops after ata7.

Perhaps unrelated, but why don't you run amd64 version?  I think PAE is
a hack, for instance it does not allow processes to use more than 2GB
memory, while AMD64 (called EM64T by Intel implementation) provides much
more...

Cheers,
-- 
Xin LI <delphij at delphij.net>	http://www.delphij.net/
FreeBSD - The Power to Serve!

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