Swap space question

Hi, i would to ask something about swap space:

i quote from the book "How Linux Works—What Every Super-User Should Know"

"Reserve two to five times as much disk space as you have real memory for
swap. It doesn't make sense to go any lower, because you may actually risk
running out of memory. If you go higher and actually intend to use all of
this swap space, you will likely suffer serious performance problems because
the system will spend all of its time swapping (a condition known as
thrashing). "

i can't understand why if create a really big swap partition i will have a
performance decrease????It seems to me
that in the worst case scenario, i will be throwing disk space [because the
system will never use the swap partition if it doesn't need it......why this
would have a negative impact on the system......]

thanks in advance,

Nicolas Ang --
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Relevant Pages

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