Juan,
Whatever you did under the hood is great. The speed of processing just blows away the old version. I assume its from the more efficient use of swap files but the improvement on my machine is amazing.
OK, just did a new benchmark test and here are the comparisons:
Under the previous version of PI: Total 5081; CPU 5038; Swap 5276; MiB/s: 952.628
Under 1.8.4.1169: Total 4711; CPU 4138; Swap 11461; MiB/s 2069.337
For reference, this is from a Samsung NP880z5e Laptop with a Core i7, 16GB of ram, and a Samsung 840 EVO 1TB SSD. I run with 6 swap files pointing to a 128Gb empty partition.
The speed increase is magical, especially those swap speeds, and I can't wait to put all that speed to use in my image processing.
Thanks Juan!!
Jim