Thank you for all your comments. I am not being disrespectful but yes, like a kid, an inquisitive 59 yr old one. I asked how many cores should I set it to. By default, the box is blank. Does that mean that the OS will control that? I remember that a few years ago, there was a problem with some game (I cannot remember what the game was now), and the suggestion was to set this to 1 and see what happened. This was how I learned that this setting exists. I didn't have that problem with regards to that game. But I did play around with it by selecting a different number of cores and see what happen. I found that for a slow machine, it seems to boot up quicker. Not a lot, just a touch. By the way, I never managed to "kill" any machine by doing this, 5 of them, if I remember correctly.
The reason why I want to find out a bit more about this is that I was planning to build a new machine with i9 9900k, 32 Gb RAM (3000 or 3200 Mhz), either an ASUS MAXIMUS Hero or EVGA mobo with Z390 chipset, GTX 2080Ti (single or SLI), 2 TB NVMe boot drive, 6 TB data drive, 1000W gold or platinum PSU, and water cool the whole system or just the CPU, a 32" Gsync monitor, most likely an ACER one. Unfortunately, this plan has gone up in smoke now due to workplace going through restructuring and I may not have a job in a few months time. So, I try to find out a bit more if I can do with my current system so that it will last another few years, allowing to play at high setting. I know I won't be able to get ultra setting with this route.
My current system is i7 5930K with Noctua NH-D9L with two Noctua fans, 32 Gb 2666 MHz, EVGA X99 Classified Mobo, 2 TB Samsung 860 SSD (boot), 1 TB Samsung 860 SSD (Steam and GOG game files), 1 x 3 TB WD (black) data drive, 1 x 6 TB WD (black) Acronis backup drive, 2 x 1080Ti in SLi (air cool), 1300W Gold EVGA PSU, Corsair 780T case and ASUS PG278Q monitor. Majority of the components were bought in 2015. The WD drives were upgraded a couple of times over the year to get to the current state. The 1080Ti were bought beginning of this year when the price came down after the 2080 series became available. I have just bought an EVGA CPU watercooler but haven't installed it as I was thinking about water cooling the whole thing. The current case will require some butchering due to the hard drive bays at the back of the front panel. This prompted me to think if I am changing it, what about... yes... no.. oh dear... Toys to boys... an old boy I should say.
Please please please, don't scold me. I know that my current system is decent already. But as an old man with still a bit of boyish thinking. Ok, I know that this ray tracing stuff is a sort of rich man thing. Comparing the range of graphics cards with their offer of technologies, sort of like comparing a sandwich to a cuisine. I accept a sandwich anytime, but every now and then, I can't help of thinking, oooh, I fancy a bit of Chinese, or Thai, or French, or Italian, or just a nice piece of steak. That is how I feel about gaming. Of course, this is all down to budget. Anyway, sorry, I digress. I would like to know how bad the bottleneck if there is one if I swap my two 1080Ti with a 2080Ti. I am playing Metro Exodus at optimized setting done by NVidia Experience, getting 100+ fps. I have finished Shadow of Tomb Raider already without any problem. Though the fps was not as high as Exodus, getting between 60 to 80+. I don't know. It seems that the surrounding in Tomb Raider is busier than Exodus. The CPU temp peaked at 71 with Exodus but for Tomb Raider, it peaked at 80 degrees Celcius. That was the reason I bought the EVGA CPU watercooler, cheaper than Corsair though. I welcome all constructive suggestion. Thanks in advance.