Thanks for the link.

I've also checked on the Avsim guide to look for an explanation (which can be very technical of course). Now the Nick and the Avsim guide are similar when it comes to 'telling' something. Don't read this the wrong way, I'm not saying this sort of spreading information is wrong or that the info itself is.  But I find it easier to follow a recommendation if the background is given and can be explained. University style.

Now what I did, being the owner of plenty of drives, is to test out if my Crysis3 or AutoCAD installation affect the FSX drive in any way. It doesn't, since there's no access happening. I've measured it and even checked my subjective impression. The latter with the help of my gf which set up a blind test for me. This avoids running into what's call the confirmation bias. Mainly, when you know that your drive is 'cleaner', you 'will see it' even if there isn't any sign at all. Human factors, huh?   :o

So when you don't know if your gf has copied over the Crysis and AutoCAD files, you are looking at your FSX in the most objective way. To be honest, I used her skills on some more tests, which was easy as she's interested in the general testing topic. Guess we share that much.  :D

Back to the drives and guides. I could read the Nick stuff in more than one way. As so often with text. I prefer formulas or the mentioned technical background. Other than the reasons given in a previous post (http://captainsim.org/yabb2/YaBB.pl?num=1375581365/11#11), I can't find anything technical which would suggest a 'better' system with three drives.

The Avsim guide does the same. It tells people to do something (not being bad at all, but perhaps having zero influence on their sim) and expects them to follow this guidance. Repeating it then makes it true. And you actually repeat it, this being the reason I asked you by the way. :) Now if they would add a chapter on the technical background and/or testing, I'd be much happier with it.

In short, I do read what they say, but I can't follow or support it without extra info. Hence my suggestion, especially for a budget system, to stay with two disks. No harm done and most likely some money saved.