From: Michael Geary (Mike_at_Geary.com)
Date: Thu Aug 05 1999 - 15:59:12 EDT
Oh! Now I get it!
> ... the difference between swappable memory and
> non-swappable memory ... loss of performance when the
> physical memory is larger than the swappable memory
> for a given chipset ... about 10% slower with physical
> memories greater than 64MB. This is the size cached by the given
> chipset in my TP770 (95491AU).
You're talking about cacheable and non-cacheable memory (not swappable and non-swappable--that's something else entirely). For a
system with only partial caching, you have an interesting point that I hadn't considered.
Suppose you have a Pentium system with 128Mb and only the first 64Mb cached. You could let Windows manage the whole thing, but it
may not realize that the first 64Mb is faster than the rest. If you could create a RAMdisk swapfile in the second 64Mb, then Windows
would do its active work in the first 64Mb, swapping pages to the slower second 64Mb.
It might be a performance win, and would certainly be interesting to find out about.
For a Pentium II or any system where all the memory is cacheable and is the same speed, what I said remains true: You're better off
just using memory as memory.
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