Sorry, I didn't have time to edit this more... Depending on whether you want portability or performance, (you will have to compromise somewhere). Even the newest Mobile processors (even the fan-less MacBooks) can still be underpowered even if they are able to stream and play HD content well, because they are optimized for smooth video playback over pure computing power. The ideal compromise would be to build a mini ITX PC using a fanless case, and at minimum an i5 Quad CPU. With laptops, you can virtually ignore models which have discrete GPU's because unless Pianoteq is somehow using Cuda cores on an NVIDIA mobile GPU* (When it's not bitcoin mining...), you are throwing money away on a GPU meant for gaming performance. An i5 2520M (Dual core) is the oldest and slowest CPU that I would recommend for mobile use of Pianoteq on a laptop, (especially if you are heavy on the sustain pedal). I use a live performance MIDI of Gershwin's "Rhapsody in Blue" as my benchmark. If Pianoteq can get through that without a sound glitch, then you have a nice live performer. If you are rendering to a DAW, CPU power is not a great concern. Look for later model i7 laptops (preferably quad-core), with Intel only graphics, if you are on a tight budget. As I said, the enhancements to most mobile processors lately have been in the GPU cores, while performance of the average CPU has not changed much, past speed boosting and multiple threads (and too much CPU speed throttling can be really bad for audio, and latency of MIDI while playing live). The best benchmark I have found for computing raw CPU power is Geekbench 4; A score of 3000 for a single core, is a good baseline for a peppy CPU that will give good audio performance, (Also look for laptops that have Realtek HD Audio, vs. Conexant chips). (An outboard ASIO device like a Korg DAC, can also help with quality and latency issues) If you have a desktop that gives a Geekbench 4 multi-core score of over 10,000, you have a machine that will probably never glitch at up to 256 note Polyphony, full sample rate, with low-latency. What you 'will' gain in newer machine however, is slightly better RAM and bus speeds, which may help with latency issues, but generally the Geekbench scores take that into account, and there are tables on their website which list thousands of models, and processor numbers, and single-core and multi-core benchmark scores, so you can get an idea of what to look for. There are many bargains to be had on eBay if you search 'no HDD' and put in a second hand SSD yourself. (Laptops that users have already upgraded to SSD, are usually over-priced anyway). For my desktop workstation, I'm running a Quad-Core i7 4790K @ 4Ghz, 16 GB RAM, and Samsung SSD, with a Korg DAC 10R for output, and also internal Realtek 887 on the Gigabyte MOBO. My MacBook is a 2010 2.4Ghz (White Unibody) with 16GB RAM and SSD. The old MacBook keeps up well with Pianoteq, Macs are much better at handling internal audio, and the efficiency has more to do with the OS than the internal hardware, because I also have a Lenovo X220 12 inch that dual boots Windows 10 and Mac OS Sierra, and sometimes Ubuntu. There are reasons I won't go into the option of running MacOS on a PC platform specifically, but for research purposes it's interesting to see what performance gains can be had on the same hardware, with different OS's, and Pianoteq affords one that ability due to it's trifecta of coding choices... From personal experience windows 10 is the least desirable in terms of setting up and fine-tuning, but with the help of "ASIO4All", and also the Korg DAC, very reliable results can be had with Pianoteq. For portability, and best latency, and no tweaking, I've found a real Mac is the most "no hassle" choice, to run Pianoteq live, (a "Hackintosh" a close second). Audio can be a nightmare on laptops running windows 10, and special attention must be given to making sure proper drivers are installed, for many of the different audio chips out there, because those chips are often the cheapest component in the budget laptops, which is one reason I recommend the KORG, or any good, fast, DAC to handle audio concerns. I have yet to test Pianoteq with Ubuntu, though, but I just installed "Bionic Beaver" (Ubuntu 18 Studio) so I hope to compare the three machines I'm currently licensed to run Standard. I hope my next build is a fanless, but also as a gamer, much of my budget has gone into the GPU. *I hinted that Pianoteq doesn't utilize CUDA cores, but what if it did?; Pianoteq "Platinum" maybe? Could you model an even more realistic piano sound with all that processing power?