I'm planning a build on an Asus ROG Maximus XII Hero (Wifi) for flight simulation and gaming.

Okay, thanks Nick. Although I like having the best performance I can get, I also value longevity and stability. With that being said I think this is gonna be a tough one. I'll look around to see what's available here. Newegg has alot more to offer for you guys across the pond.

Yeah, that's why I am aiming for a manual all core 5 GHz. Not sure yet if hyperthreading is needed. I guess it depends on the game and I guess I will have to test if it makes a difference but having two or more profiles to test for stability can get tedious so I will probably turn HT off for starters. And I mean ten cores at 5 GHz should be enough for most games I assume. If I can get 5 GHz, I'll lock it. It's been 7-8 years now since my last build and I will probably hang on to this new build for at least five years or more. I also play Euro Truck Simulator 2 and first person shooters in addition to flight sim.

Thanks for your input. No, I'm not ahead of the curve, I was just thinking that with the new rig I will be able to play more modern games and maybe they have been developed more for HT so the question popped up in my mind. I don't do professional or video editing stuff. Just flight simulation and games. 

I've been looking around and it seems I can get most of the kits discussed. But this 'issue' or question comes back to mind and that is...is 2x16GB more difficult to run than 4x8GB for the CPU/Motherboard with everything else being the same? And it goes back to the recommendations/QVL of both Gskill and Asus because the performance numbers of those 4x8GB kits can not be found in 2x16GB kits. So from that, I have begun to draw conclusions (conclusions that may be false) that 2x16GB kits are harder to run at the same speed and latency than 4x8GB kits. I mean, it's easy to come to that conclusion with the lists provided, unless there is some kind of delibarate choice being made not to develop/produce 2x16GB kits with the same performance as 4x8GB kits. But this whole thing pushes me towards 4x8GB kits even though it is not needed for dual channel, and with a drawback that with four sticks, there are two more sticks there can be issues with.

To rephrase what I outlined above..

I understand why the question on voltage with the difference seen between the 2 options. You are thinking why are the 4 stick top ends running 1.45-1.5 and there are no 2 stick options in that range and coming to the conclusion that the higher memory amount per stick was difficult to keep stable at higher speed. logical

Yea, you haft'a look at it from the memory/motherboard manufacture point of view. They are supplying a customer 2 sticks @ 16GB and if the customer were to opt to add 2 more right away or down the road, then there is no way in hell those sticks are going to run the top-end speed/latency at a reasonable voltage so they sell those tamed back

Yea I have noticed the same thing. They have moved away from nice large side fan ports where a large fan moves a lot of air and makes little noise to these disco towers. I cut the wires to the LEDs on any fans that might come like that if the tower wont allow them to be turned off.

Ted striker wrote: Hans, I was in the same predicament as you. My current case is old Antec 193 with a 200 mm side fan. It has been solid, reliable, and cool ever since I built this system in 2013.  https://www.newegg.com/black-antec-performance-one-series-atx-full-tower/p/N82E16811129176 The reason it shows out of stock is because it isn't made anymore and I couldn't find any other cases with a big side fan that I liked. It seems that people are more interested in light shows than good cooling these days. I would have reused the Antec P193 but it doesn't have enough room on top for a 360 mm radiator. I instead settled on this Fractal Design 7 XL case which is a new model, has plenty of room for radiators, and can be purchased with metal side panels to allow installation of a large side fan if desired. I have an EVGA hybrid cooled 1080ti and there is room to mount its radiator on the back side. https://www.fractal-design.com/products/cases/define/define-7-xl/black/ I can easily install the 200 mm fan from my Antec P193 into the 7 XL if I need to. The extra bonus for you is that Fractal Design is based in Sweden. Thought you might be interested, Ted

Thanks Ted, that case looks really interesting. I keep it in mind.

Okay someone who has mounted a 360 rad in the case:
https://www.overclock.net/forum/18082-builds-logs-case-mods/1577796-work-log-custom-water-cooling-thor-v2-360mm-240mm-radiators.html

You won't hit the top end communication performance with 2 sticks until such time as the memory manufactures make changes on their end. 

I just threw the case option out there.. I know your options might be limited.

You're going the right way Hans, you will be fine with a new rig. I didn't doubt it

There is a Corsair HX850 without the "i", which has a switch on the back for single/multirail. So no corsair software needed for the switching of rails. It's about $30 cheaper than the HX850i. Are you using the software for anything else than the switching of rails?

Hans..  I have some news for you about the H150i Pro

Interesting, thanks.

Thanks Nick, and good job. I'll use the Corsair iCUE software then. So you're not running the CPU clock the same way as you did with the Haswell, meaning fixed CPU clock speed but variable Vcore? You're running both clock speed and Vcore variable now, depending on load?

Okay. I made some orders of parts today. So here's the list so far:

ASUS ROG MAXIMUS XII HERO (WI-FI)

Intel Core i9 10900K

Corsair iCUE H150i RGB PRO XT

Gskill F4-4000C15Q-32GTZR (at least two weeks of waiting)

Corsair HX850

Fractal Design Define 7 XL - Black Solid (FD-C-DEF7X-01) 

Noctua NF-A20 PWM (side fan for the tower)

Samsung 970 EVO Plus 1TB

Video card and 2nd drive will be added later.
This is gonna keep me busy for a good while.

Obtain a recent version of the boot stick memtest for your offline test. The version from the old bible thread is outdated for DDR4. You shouldn't have a problem locating. I'll look if you cant find, however run your individual offline stick tests to be sure you don't have hard dud.