Hi folks, I'm looking for expert advice on choosing the best component combinations for a new customized PC. I am currently using a moderate rig for FS9 - Dell Optiplex 780, x64; Intel Core 2 Duo CPU @ 3.00GHz; Radeon HD 5450 GPU; 8GB RAM; Windows 7. and it all runs pretty well on 4 monitors using Maxivista to enable monitors 3 and 4. However, I am in the process of building an enclosed cockpit (in the attic!) and will be moving to FSX and perhaps up to 6 to 8 monitors, using Matrox TripleHead and/or Maxivista - I haven't worked that out yet. As we all know, FSX is very CPU demanding and my first critical decision is which processor to opt for. Four of the choices offered on the customized units I have been considering are: a> Intel Quad Core i7 4790 3.6GHz 8MB cache b> Intel Quad Core i7 4790k 4GHz 8MB cache c> Intel 6 cores i7 5820k Extreme 3.3GHz 15MB cache d> Intel 6 cores i7 5930k Extreme 3.5GHz 15MB cache. I'm not sure what the "Extreme" is about. I can't see it on intel spec sites. Maybe it's just a marketing thing. Anyway, my question is : Is option b at 4GHz with 4 cores and 8MB cache better than c or d which both have less GHz, but 2 more cores and higher cache? High default clock speeds are apparently very important for FSX, as are higher processor caches, and 6 cores is recommended over 4, but only if comparing the same class of processor. So I'm not sure which way to go. Expert advice would be very much appreciated. Incidentally, I have lots more questions if anyone here has the time and generosity to help me. Kind regards, Philip