Computer Audio Asylum: oops - correction by Paul Tobin

Abe, since installing the i7 mini I'd been doing a fair bit of filter experimentation with HQPlayer and had established a preference.
As I stated above my feeling was that the i7 mini was outperforming my previous i5 - though I hadn't done any serious comparisons with my new settings.

Anyway, since I still have both in my rack I went back to the i5 and set up HQPlayer with my latest filter preference (poly-sinc-xtr for PCM and 2s version with DSD128 up sampling). I was really quite taken with how engaging the music became. There seemed to be an extra layer of refinement and subtlety.

Now this is not a completely level comparison because the i5 system has the Uptone JS2 linear PS while the i7 is running with its internal SMPS (off a seperate ac circuit from the hifi gear). Both minis had their USB output running through the iFi usb3 decrapifier/regenerator into the PSA dac.
I've probably underestimated (forgotten) the performance improvement brought by JS2 amongst all my filter trialling.

The Uptone PSU requires removal of the SMPS and retrofitting of a replacement PS board - of which I only have one. The installation of the board requires a complete teardown of the mini - so quick comparison here is not really possible. That's something I'll have to get around to with the i7 mini.

One thing for sure, the i5 obviously struggles more with SDM up sampling. With my settings it runs at ~33% CPU load. Which is ok most of the time though stutters can be induced if I utilise the Mac for other stuff while listening - this never happened with the 4 core i7 on the same settings. The other thing about higher CPU loads with SDM up sampling is that the mini fan can kick in (ambient temp dependent) - which causes audible noise.
On the other hand the i5 system sounds really good with just HQP PCM up sampling and CPU load is minimal for that.
Some more experimentation required.

Edit: FWIW I've now transferred the Uptone linear PS to the i7 mini (High Sierra 10.13.4) - sounds great, will listen for a while and compare to the i5 El Capitan mini. Still yet to encounter any issues with High Sierra.