Re: Undersized L2 cache: any tricks?
thunder7@xs4all.nl
Tue, 16 Mar 1999 07:26:27 +0000
On Mon, Mar 15, 1999 at 09:40:36PM -0500, owner-linux-kernel-digest@vger.rutgers.edu wrote:
> From: "B. James Phillippe" <bryan@terran.org>
> Date: Mon, 15 Mar 1999 16:33:15 -0800 (PST)
> Subject: Undersized L2 cache: any tricks?
>
> Greetings,
>
> Some co-workers of mine have put together an x86-based system on which to
> run Linux, which has 256MB physical memory and 512k L2 cache. The
> processor is something like an AMDK6 3XXMhz or Pentium equivalent. To no
> surprise, the system runs slower with the full 256MB than it does with
> 64MB, I'm guessing due to the undersized cache. The problem is that the
> mainboard is apparently only capable of 512K of L2 cache. I am not an
> expert in memory/cache-related stuff, but my guess is that there is no
> performance solution other than to decrease the physical memory (or get a
> new mainboard). The kernel is 2.0. Are there any other options?
There is no connection between cache-size and the amount of memory it
can accomodate. Their is a connection between the chipset and the amount
of memory it can accomodate. All intel-slot7 chipset with the exception
of the HX chipset can only cache 64 Mb, and the HX only more if you
extend the tag-ram. non-intel-slot7 chipsets should be able to cache
more, but some may not be able to cache 256 Mb. Sometimes switching the
L2-cache to write-through instead of write-back will gain another factor
2 in the cacheable memory. If that doesn't help, I'm afraid a new
motherboard is due. Or use it as ramdisk/swap area.
Good luck,
Jurriaan
--
All this being the case, I feel that the off-worlder's opinions should
be carefully heeded.
True, said Morlock, especially in view of the powerful warship.
Jack Vance - Nightlamp
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