Please look very carefully into your RAMDisk setup and possibly the AutoHotkey config (if you use that to startup XX), because this is totally impossible.
I solved the problem late last night but was too tired to post: What happened was that I did activation only in XX run from RAMDisk. When I did a _proper_ activation i.e. when XX was started from SDD it didn't go to demo mode after reboot.
See. It *must* be something else.
I'm afraid I don't understand a word of what you just said
(especially that thing about 'profiles').
We may have a misunderstanding here which is probably my fault for not more clearly explaining what I did and what I 'saw' so let's try it this way:
1. Open ProcessExplorer and add column 'CSwitch Delta' to display
2. Let XX play using Engine #4
3. You should _not_ see any increase in CSwitch Delta next to your svchost.exe processes (some go up & down at times but that is normal)
4. Now let XX play using Engine#3
5. You _should_ see one of those svchost.exe go to 100 CSwitch Delta: If you have a quiet system this will be obvious as previously it was probably not active at all (my case). And it is 100 because MMCS gets activated every 10ms per MS defaults. How do we know?
6. Right-click svchost.exe->Properties->Services: MMCS should be in the list.
That's it.
So this is purely an objective technique to prove when MMCS gets activated. As I said, what/if it does anything to sound and whether it is really influenced by registry tweaks is beyond this - I plan to test that later but it's not my priority (as Engine #4 simply sounds better).
And about testing IRQs: it's also easy:
1. Open ProcessMon and look at DPCs queued/sec & Interrupts/sec.
2. Do this with different Interrupt Affinity tool settings (e.g. affinity to CPU0, CPU1, none)
3. You should see a clear pattern of (especially DPCs!) following CPU you used for affinity
Again: keep in mind that reboot is required after changing affinities.
Also, and this is what I discovered later, if your sound device shares IRQs with other devices you MUST set all of those to same CPU! For example, my laptop has 2 USB ports but both share same IRQ. So, in effect, sound device (solo on port 1) was sharing IRQ with mouse & HDD on port 2. Device Manager showed 3 'Host Controllers' associated with this same IRQ. I had to set affinity for ALL of them to be the same, otherwise it didn't work.
So, again, no subjective (listening) impressions here just easily observable facts.
Please do try these 2 simple experiments and post your findings!
You never know, maybe there is something weird about my laptop or I have made a mistake (and I can certainly make some, like 'rogue' Q2 setting from last week
Well, at least we all learned about what Q2 really does and it is quite amazing in it's own way but that should go into a different topic
)