With 5K$ I would personally start with this as a base PCPartPicker part list
Add this drive for OS/apps: https://www.newegg.com/Product/Product.aspx?Item=N82E16820167440
And finally start with two of these: https://www.evga.com/products/product.aspx?pn=11G-P4-2281-KR
Grand total ~4900$
- I would personally prefer the 9900K for its out of the box top single threaded performance.
- With 5K$ I wouldn’t compromise with anything else than the 2080Ti, with the hope that some day Cycles gpu rendering will be able to use nvlink, which is the greatest new feature of the RTX series, i.e. the capability to add Vram via nvlink bridge and use it as one greater memory pool (2x11=22gb Vram).
- The EVGA 1600W T2 is one of the best psus out there (based on a Superflower platform) and will be able to handle up to 4 x 2080ti’s if needed.
- The MSI MEG Z390 Godlike is the only Z390 that’s suitable for gpu rendering with its plx chips. Pcie bandwidth is really needed only just before rendering begins, during the transferring process. Usually even x4 is adequate for this job, but with this motherboard every gpu slot will have the bandwidth it needs the moment it needs it.
Finally, as an alternative build you could choose a 2950X-Z399 combo. It would be slightly faster in final renderings (with hybrid rendering), but for anything else, where single threaded performance is paramount, it would be slightly slower compared to the 9900K.