Workstation advice (for mostly Julia use)

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julia> @benchmark directexp!($c, $a, $b)
BenchmarkTools.Trial: 
  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     17.050 μs (0.00% GC)
  median time:      17.120 μs (0.00% GC)
  mean time:        17.461 μs (0.00% GC)
  maximum time:     49.566 μs (0.00% GC)
  --------------
  samples:          10000
  evals/sample:     1

julia> @benchmark cobexp!($c, $a, $b)
BenchmarkTools.Trial: 
  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     23.517 μs (0.00% GC)
  median time:      25.084 μs (0.00% GC)
  mean time:        27.077 μs (0.00% GC)
  maximum time:     114.213 μs (0.00% GC)
  --------------
  samples:          10000
  evals/sample:     1

julia> @benchmark syspow!($c, $a, $b)
BenchmarkTools.Trial: 
  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     15.135 μs (0.00% GC)
  median time:      15.856 μs (0.00% GC)
  mean time:        16.032 μs (0.00% GC)
  maximum time:     56.076 μs (0.00% GC)
  --------------
  samples:          10000
  evals/sample:     1

julia> @benchmark jsleefpow!($c, $a, $b)
BenchmarkTools.Trial: 
  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     16.094 μs (0.00% GC)
  median time:      16.188 μs (0.00% GC)
  mean time:        16.904 μs (0.00% GC)
  maximum time:     76.149 μs (0.00% GC)
  --------------
  samples:          10000
  evals/sample:     1

julia> @benchmark csleefpow!($c, $a, $b)
BenchmarkTools.Trial: 
  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     11.834 μs (0.00% GC)
  median time:      12.207 μs (0.00% GC)
  mean time:        13.216 μs (0.00% GC)
  maximum time:     63.291 μs (0.00% GC)
  --------------
  samples:          10000
  evals/sample:     1

julia> @benchmark xsimdpow!($c, $a, $b)
BenchmarkTools.Trial: 
  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     6.904 μs (0.00% GC)
  median time:      6.982 μs (0.00% GC)
  mean time:        7.218 μs (0.00% GC)
  maximum time:     26.691 μs (0.00% GC)
  --------------
  samples:          10000
  evals/sample:     5

julia> @benchmark jsleefpowcob!($c, $a, $b)
BenchmarkTools.Trial: 
  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     7.863 μs (0.00% GC)
  median time:      8.010 μs (0.00% GC)
  mean time:        8.409 μs (0.00% GC)
  maximum time:     28.134 μs (0.00% GC)
  --------------
  samples:          10000
  evals/sample:     4

julia> @benchmark csleefpowcob!($c, $a, $b)
BenchmarkTools.Trial: 
  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     5.140 μs (0.00% GC)
  median time:      5.274 μs (0.00% GC)
  mean time:        5.662 μs (0.00% GC)
  maximum time:     25.680 μs (0.00% GC)
  --------------
  samples:          10000
  evals/sample:     6

julia> @benchmark xsimdpowcob!($c, $a, $b)
BenchmarkTools.Trial: 
  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     5.515 μs (0.00% GC)
  median time:      5.578 μs (0.00% GC)
  mean time:        5.756 μs (0.00% GC)
  maximum time:     17.309 μs (0.00% GC)
  --------------
  samples:          10000
  evals/sample:     6