I intend to build a PC that will use Linux as a host system, and then to run Windows as a guest within a Virtual Machine; I will use VFIO to pipe a second GPU into the Windows VM, so that the Linux host has its own GPU and the Windows guest has its own GPU.

Currently, I have a RX580 GPU. This is the GPU that I will use to power the Linux host. I need to purchase a GPU that will be used to power the Windows VM.

I also have a 2700X Ryzen CPU, but I wish to upgrade this(I want 8 cores due to running two Operating Systems). I have a Pro 370x-prime motherboard, and a RM650x PSU. I want to buy new RAM; I want 32GB, maybe 64GB.

Here is a proposed build:

https://au.pcpartpicker.com/list/3f69pH

I'll also need to buy some RAM. I am clueless as to what RAM to buy; I read faster RAM helps with the CPU bottleneck issue with a lot of my games.

I'm told that I can use the Max Wraith cooler that's attached to my 2700x, and apply it with thermal paste to sufficiently cool the 5700x.

This configuration will put the PSU to its maximum capacity. Using a more powerful CPU or GPU will require to additionally purchase a bigger PSU. I can use a 6600xt instead of a 3060ti.

The games that I wish to play are:

Civilization IV with huge settings. It takes not much more than a second to complete a turn early game on my 2700x; late game last time I recorded it took 104 painful seconds to complete a turn. I really want to speed up this painful late game. Mount and Blade Warband, with battlesizer mod pushing the game to have far more units than it was designed for. THe original game's maximum unit count was 150; I can play about 300, but it lags too much when all the units fight at the same time. I want to be able to play with more units(more the better) without it lagging so mucy. Paradox Games, specifically Europa Universalis IV and Crusader Kings 2/3. These games have lag issues late game where it becomes sluggish. I read the cache of the 5800x3d has high performance gains in a related game, Stellaris. I also read that the 5800x3d had vastly superior performance over the 5950x in Crusader Kings 3. I read a comment saying how the cache helps games that have massive AI interactions going on, which makes me wonder if it'd help a lot with Civilization IV.

Kingdom Come Deliverance: game is very CPU bottlenecked lagged at certain times

Modded Skyrim. I want to play with ENB and being able to visually see at distances as well as some graphic mods. This will be demanding on a GPU and I'll require minimum 8GB VRAM; the more VRAM I have the more additional mods I'll be able to use. My 580x could manage this on medium settings/mods enchancments and it was always running at 100%. I'd like to be able turn up the settings and graphical mods I use by a bit, whilst having GPU usage under 100%.

I've found quite a lot of references on the internet to Skyrim having issues with AMD due to a driver issue (something to do with draw cells). This is a quote I found best explaining it: "AMD d3d11 standard drivers seem to be a mess compared with the with nvidia ones (at least for fo4 performance). one reason: multithreading support still sucks"

"extremely heavy on instancing and scene complexity (even if they don't look the part), especially in modded games where mesh combining isn't supported by the engine. It is not difficult for modded Fallout 4 to demand in excess of 20,000 draw calls per frame, even if needlessly so.

This means that it basically passes a developer concern (which is managing object instances) straight into the graphics driver, and the Radeon driver is not capable of supporting driver-level command lists and deferred contexts in Direct3D 11, choosing instead to operate in an immediate context instead." I however read that AMD released a sem-recent update for their direct X 11 driver, so those issues described above may have been mitigated or entirely fixed. I also read that AMD Vulkan can mitigate those problems described above. I also read that on top of that, AMD is very poorly optimised for ENB that I wish to use.

I also read that the 5800x3d provides major benefits to modded Skyrim, due to the cache directly mitigating a primary bottleneck issue: the draw cells.

I also read that the AMD cards aren't as reliable with VFIO and can cause issues. The 6000 series AMD cards, and especially with the navi 23 cards. Supposdely, the 6800xt is less likely to have some of these issues, as it's navi 21.

I think my options are:

5700X 6600XT/3060ti

Upgrade PSU, then can use a 6800XT or 3080(the 3080 is quite expensive in my country) or 5800x3d, or 13600k suitable motherboard. All these options seems like a lot of extra money for maybe not a whole lot improvement, but I'm open to suggestions.