Date: Tue, 12 Jun 2001 13:10:49
From: "neil barnes" <[EMAIL PROTECTED]>
Subject: Re: Re[2]: Waterfall Pro and Libretto
So, having had it set on 'write through' as long as I've been using it, I
looked it up...
Write-through caches ensure that on each write to the cache, there is a
corresponding write to the main memory. Therefore, whatever is in main
memory is what the processor thinks is there.
Write-back caches only write the data from the cache to the memory when the
space in the cache is required for something else.
Statistically, it appears that reads are much more likely than writes, and
that read-modify-write is more likely than write once and that's it. The
snag with the first system is that there is a slow write cycle on *every*
write, though the data is still in the cache if it is required again in the
near future. With the second system, the write only occurs after a read
instruction needs its space and it has to be cleared down.
This suggests that depending on program source, the write-back is generally
a quicker option. I shall have to try it.
There's always the possibility that the hibernation code doesn't see the
exact code in memory that should be there...but I can't believe that they
would have implemented it to save without flushing the cache first.
Neil
>From: VD <[EMAIL PROTECTED]>
>Reply-To: Libretto <[EMAIL PROTECTED]>
>To: Libretto <[EMAIL PROTECTED]>
>Subject: Re[2]: Waterfall Pro and Libretto
>Date: Tue, 12 Jun 2001 02:27:05 -0700
>
>Date: Tue, 12 Jun 2001 13:23:36 +0300
>From: VD <[EMAIL PROTECTED]>
>Subject: Re[2]: Waterfall Pro and Libretto
>
>What is the difefrence between "write-through" and "write-back"
>policies for CPU cash in BIOS Setup?
>
>Best regards,
> VD mailto:[EMAIL PROTECTED]
>
>
>
>
>
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