Win 7 64-bit; i7-950@3.07GHz; 16GB RAM; OS on SATA 6GB/s SSD; AIFF files on external FW HDD; XXHE and Playback Drive on separate RAMdisks; no page file; Audioquest Dragonfly DAC/preamp; PSE Studio IV amp; Pioneer SP-BS22-LR bookshelf speakers or Etymotic Research ER-4P in-ear monitors.  XXHE 0.9z-8-3a settings for the moment: Peak Extend; Arc Prediction; Redbook files upsampled 2x; KS Adaptive Mode; Phase Alignment off; buffer=512; Straight Contiguous; Playerprio=Low; ThreadPrio=RealTime; Unattended; OS minimized; all services off; Q1=17, factor=2; SFS=2.1; XXTweaks=Ultimate; Time Performance Index=Not the best.