Sorted index array Vs. triangle strips

Triangle strips are fast, but why exactly?
Is it because they never have a cache miss, or is it because the cards
have some special optimization just for triangle strips (and fans)?

If I, instead of a triangle strip, have a vertex buffer and en ordered
index buffer so that the indices mimics the order of a triangle strip,
will this be just as fast as a strip? .. or is there something else to
it?

I have a mesh where a triangle strip can not easily be built, but I can
however order the indices in such a way that each triangle reuses two
vertices of the previous triangle. Each primitive only introduces a
single new vertex (index). How would the performance be?

I could test this, but I would like to have a theoretical answer first
and then make real world comparisons afterwards.

Just as an example. The index buffer could look like this

0,1,2 - 1,2,3 - 2,3,4 - 3,4,5 - 3,4,6 - 3,4,7 - 3,7,1 - 1,7,2

The only thing I can say about the order is that only one index changes
between to consecutive triangles.

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Someone suggested that triangle strips are fast because the indexes
does not need to be calculated. I hardly see that this should be an
issue. Using an index array, indexes are read - not calculated. Apart
from this read, why would a triangle strip be faster than a properly
sorted index array?

.