Hi John,
First, as you undoubtedly realize the answers to most questions regarding configuration of a computer for audio applications figures to be dependent on the specific computer, the specific DAC that is being used, and the specific system, and therefore to not have a great deal of predictability. So I would resist any temptation to extrapolate too broadly from experiences you may see reported. One reason for that, among many, being the rapid pace of changes in computer technology, meaning that experiences from just a year or two ago may no longer be relevant.
That said, my perception has been that approaches which seem to be recommended with a high degree of consistency include playback of music files from a drive other than the one on which the operating system and programs are running (which you are already doing); running the operating system and programs on an SSD rather than on a mechanical hard drive; and having a goodly amount of RAM (e.g., 8 or 16 gB).
Beyond that, my suspicion is that choosing the generation of the Intel CPU that is used is likely to be a much more significant factor than choosing between an i3 or i5 or i7, each of those designations having been available across multiple generations. Specifically, I would suggest that your choice be one of the latest 6th generation Intel CPUs. Due to their considerably reduced power consumption, compared to CPUs from previous generations having comparable speeds, I suspect that the 6th generation devices will generate significantly less digital noise, that may ultimately affect jitter at the point of D/A conversion.
Regarding Windows 10 Home vs. Pro, I have no direct audio-related experience, but having looked at descriptions of their differences, and having used both for non-audio purposes, I see no reason to not go with the less expensive Home version, as Bob (Gdnrbob) suggested.
Regarding AMD processors, I have no basis for an opinion.
Regarding eliminating "fluff," assuming a reasonably capable recent generation processor I suspect that a more important factor than turning off unneeded Windows processes would be having the machine free of useless third party "crapware." Which these days seems to come copiously pre-loaded on machines from most of the major (and even minor) manufacturers, and can often be troublesome to fully eliminate.
Which brings me to my specific recommendation, if you decide to go with a laptop as you indicated, rather than building your own small computer as Bob suggested (which is also an approach well worth considering). Having owned laptops made by Asus and Sager, and having significant experience helping others deal with problems involving laptops made by HP, Dell, Lenovo, etc., (and also having built numerous desktop machines myself), by far my most positive experience with a laptop and with a laptop supplier has been with one I bought earlier this year from a company called
Eluktronics. Like Sager and some other small companies they customize laptops OEM’d by a Taiwanese company called Clevo, but they do it well, and by virtually all accounts (including mine) are a great company to deal with. Especially among computer manufacturers :-) And the Eluktronics branded computers they sell are totally devoid of crapware, with only the Windows OS and necessary drivers installed. I wanted a powerful model for non-audio applications, and so I purchased one of their somewhat upscale models, the PRO15RE, configured with a number of extra-cost options, but I suspect one of their lower priced models would serve you well for audio.
Regarding your preference for a backlit keyboard, btw, the PRO15RE I bought includes a very nice one, as well as a beautiful IPS display. I haven’t checked, but I believe that many and possibly all of their less expensive models are similar in those respects.
I have no affiliation with Eluktronics or any other computer (or audio-related) company, other than as a very satisfied customer.
Good luck. Regards,
-- Al