[TUHS] block operations in editors, was My EuroBSDcon talk

Jon Steinhart jon at fourwinds.com
Wed Sep 18 14:52:24 AEST 2019

Steve Johnson writes:
> This is one of my pet peeves.  "Random Access" memory is far from random when
> you look at the time it takes to do the accesses.  With modern memories,
> accessing a column can be 20 to 40x slower than accessing a row.  This is
> particularly irritating when doing AI training, where training reuses 4-d
> tensors transposed, a very painful operation.
> In FORTRAN days, I once used a vector package in which you described a vector
> by giving the first element, the second element, and a count.  So you could
> describe rows, columns, a matrix diagonal, and even rows and columns from back
> to front.  Fortran passed arguments by address, which made the whole thing easy
> and fast.
> Steve

Remember the words of that great performance pioneer Jimmy Durante: ras-a-ma-cas.

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