Re: tcatm’s 4-way SSE2 for Linux 32/64-bit is in 0.3.10

The difference between new and older CPUs is pretty easy to explain.
Older microarchitectures have 64-bit mmx/sse execution units and split 128bit sse ops into 2 64bit microops.
Newer archs have 128bit sse units.

  • AMD K8: 2 64bit units
  • intel Core/Core2: 3 64bit units
  • AMD K10: 2 128bit units
  • intel nehalem: 3 128bit units

K10 = Opterons with 4 or more cores, Phenom, Phenom II, Athlon II
nehalem = xeon 34xx/35xx/36xx/55xx/56xx/65xx/75xx, i3/i5/i7

Thanks for clearing that up.  I read the link someone posted about AMD making that change around 2007, but I didn’t know what the story was for Intel.

There’s no hope for Core/Core2 then.  They only have half the SSE2 hardware.

Strange that Intel has 3 128bit units, but AMD with 2 128bit units is the faster one.

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