Re: Linux Kernel Microcode Question

[Dave Jones]

On Thu, Mar 18, 2004 at 04:40:49PM +0000, Justin Piszcz wrote:

 > My question is, what are the advantages vs disadvantages in updating your 
 > CPU's microcode?

It'll fix known problems in the microcode thats in ROM on your CPU.

 > Is it worth it?

In most cases, yes.  It's zero cost. You don't waste RAM, as the
microcode gets loaded into small RAM areas on the CPU that are
otherwise unused.

 > Does it matter what type of Intel CPU you have?

yes. You need at least a Pentium Pro.
Also Pentium 4 needs a newer format microcode, which isn't available
publically anywhere yet afaik.

 > Do some CPU's benefit more than others for microcode updates?

Some CPUs have more bugs that need fixing than others 8)
Additionally some CPUs may not have a newer microcode available
than the one that it shipped with in ROM

 > Can anyone explain reasons to or not to update the CPU microcode?

In some cases, your BIOS is doing this transparently already.
I've seen instances where moving a CPU between two motherboards
has meant that microcode_ctl has done an upgrade on one, and
done nothing on the other as its already up to date.

If you're already up-to-date, theres no reason to run it.

		Dave

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