I don't know if my reply adds something interesting/relevant, just in case...
I think Pianoteq relative perfomance in Linux/Windows is a bit intrincate, at least in my experience.
I've had the following setups since 2010 (started using Pianoteq in 2014):
(1) Acer Aspire 5542 5241, AMD Turion II Dual-Core Mobile M500, 4Gb RAM
(2) Bangho (the argentinian name for Chinese Clevo) Intel Pentium CPU 2020M @ 2.40GHz, 8Gb RAM
(3) Gfast (an Argentine brand for some Chinese generics) Intel Core i7-4710MQ @ 2.50GHz, 8Gb RAM
(4) MSI GL62M Intel Core i7-7700HQ @ 2.80GHz, 8GB RAM
On laptop (1) Pianoteq run smoothly in Windows 7 64bits at 44100KHz with the internal sound chip and ASIO4all, selecting the minimum buffer size. Only Pianoteq, no other programs. WiFi had to be deactivated*.
Sometimes CPU got overloaded, but it was playable in general. The computer would get hot from time to time, with a constant CPU load over 60-70% while playing.
One sad day, the CPU got burnt (not while using Pianoteq).
I could not manage to make it work in GNU/Linux (tried ALSA / pulse audio / JACK, 32 and 64 bits). In any case, I would get lot of pops, clicks and CPU overloads.
Computer (2): I could use internet and other programs while playing, it worked very well in Ubuntu Studio (64 bits), I could whatch YouTube as I played, using 'pulse audio'. Usually I used ALSA directly. Never installed Windows on this laptop while being used for Pianoteq.
Sometimes Pulse Audio changed the sound card frequency and the sound got distorted and the pitch transposed...
This was a very generous setup, in the sense that I got lot of red lines in the performance tab of Pianoteq options but the sound never went away, even if I tried to by playing lot of bass chords and notes with damper pedal (at least at 44.1/48 KHz).
I reactivated CPU frequency scaling (ubuntu studio fixes the cpu to max freq) and the system worked properly.
For (3) with Ubuntu Studio, I could set the frequency to 192KHz and the program would play well. I used to open two instances of Pianoteq to have, with an external sound card, more outputs, and it ran flawessly. Only one issue: WIFI and Pianoteq again not compatible*.
Latter I installed Windows 10, and the performance was much poorer than in Linux. The program detects overload and mutes if I use much pedal, even though windows task manager says there is about 5% of CPU load. A little message saying that CPU is not powerful enough or my power saving settings are too aggressive pops up, even if the energy plan is set to high performance .
I have had (4) for only a few weeks, and the behavior is very similar to (3), may be a little better, with a no minor improvement: I can connect to WIFI. I have used only Windows 10, perhaps I will install Ubuntu Studio later to compare.
I don't know if it true, but for some reason I feel that the Acer laptop had the best sound of all.
Based on my experience, the order of perfomance seems to be W7 > Ubuntu Studio > W10. Anyway this order is based on particular cases.
More tech details (I don't know what is more relevant for Pianoteq)
CPU Clock Cores Threads L1 data L1 instr. L2 L3 Bus sp. RAM cl. Thread PassMark CPU PassMark
m500 2.2GHz 2 2 2x64KB 2x64 2x512KB - 3.6GT/s 667MHz 744 1307
2020m 2.4 2 2 2x32 2x32 2x256 2MB 5 1333 1253 2298
4710mq 2.5** 4 8 4x32 4x32 4x256 6 5 1600 1897 7995
7700hq 2.8** 4 8 4x32 4x32 4x256 6 8 2400 2027 8984
*The WiFi issue may be due to interrupts on the same IRQ than sound card, I remember they could be changed in Windows 95, but I could not do it on Windows 7 (there was a very funny W95 hanging event if you tried to use a diskette while playing music... this could be avoided if IRQ of the diskette was set different than the sound card).
**Those CPU feature 'turbo boost'. For (3) it is disabled since the motherboard doesn't support it. A core in case (4) can go up to 3.5GHz.
Pianoteq Pro - Bechstein - Blüthner - Grotrian - K2 - Kremsegg 1 & 2 - Petrof - Steingraeber - Steinway B & D - YC5
Kawai CL35 & MP11