TheDankKoosh

The only changes available to AM4 X3D chips are curve optimizer (via PBO2 tuner) and BCLK changes, you cannot raise max load voltage beyond ~1.2v as it's fused at the factory to do so, mostly to protect the 3D cache. Most you're likely to get without a clockgen is 102 BCLK AKA +84mhz to core clocks, best you should reasonably do with your system is to just undervolt via PBO2 tuner to ensure max clocks are getting reached in game, definitely give the ram a tune for less stutter in games.

If he's going to be more or less exclusively sourcing the major parts from Aliexpress then he may as well go with the Erying 11980hk(ES) board which will outperform anything that's been suggested thus far and comes in close to the same price as a chip+ali x99 board. Intentionally cheaping out on the PSU is silly when $10 could mean the difference between a ticking bomb with newly purchased parts and a multiple years steady system, common sense and a little reading will allow you to get a cheap power supply that won't have those issues.

Whichever is at least 6-core with the highest clock speed possible if this is just for gaming, but unless you already have a board for broadwell xeons you're going to be paying a premium for nearly 10 year old hardware.

If you want a cheap 1080 based rig and you already have the card and nothing else, grab a lenovo P520 from ebay with a W2135 and 32gb of ram, you'll get more cores/cache along with quad channel and skylake arch for better IPC. Whole systems without drives can be had for $200 and a $40 dollar nvme will make it a very capable gaming rig.

TDC being high doesn't necessarily mean that your chip is actually pushing 140% of its typical amperage except under the most intensive scenarios like P95 small ffts, I'd say you're gonna be hovering around 100A at 1.25v (aka 125w) for your nominal max power draw unless you're under a good AIO or custom loop.

Best results will be had from your chip by utilizing PBO2 overclocking options, maxed out power limiters and +200mhz PBO settings will give you the best performance on Zen 3. A little extra performance to be had by tuning with a negative curve optimizer offset, all of this should be set in the BIOS though. After that focusing on memory/fclk and tuning timings will give you much better gaming performance. Test out the above settings I suggested with something like a -10 all core CO offset and see how you chip is boosting, if everything looks good I can assist in memory tuning, but I will need info on your memory config and what ICs your memory is using. Thaiphoon Burner is generally a good tool for this

Using both zen and zen+ chips I could not get a brand new b450m ds3h to do anything above 2133 mhz memory which was very limiting with my 2600. Even now on this B550 UD AC I have lesser issues with the on-board usb 2 refusing to function even at bone stock settings and kinda wish I would've coughed up the $200 when I saw a B550 unify-x up for sale

Easily the 5500, zen 3 cores and no cross ccx latency make the 5500 overall a stronger chip despite half the cache. The 5500 being a monolithic zen 3 design can also do crazy memory speeds which will make a pretty good difference in gaming if you learn how to tune ram, access to curve optimizer is also very handy as you should be able to do -30 all core without issue since the 5500 only has a max all core boost of 4.25ghz.

The earlier wraith stealth coolers have a copper slug in the middle which performs a bit better than the all aluminum model that gets thrown in the box now. Either way using a -30 PBO curve optimizer offset should tame any temp and boosting issues.

A maxed out curve optimizer offset of -30 all core will be highly recommended then, the newer AMD stock coolers are only slightly better than non-k intel coolers.

It wouldn't kill your rig to go 16gb but you may get limited in some scenarios. The midrange and up models are generally decent, but low end gigabyte on AM4 has only ever given me trouble, which is anecdotal, but this notoriety is not just coming from me. Do you already have a cooling solution or are you sticking with the stock cooler?

Either of those two alternative boards will be far much less of a nightmare compared to that S2H, I'd wager the msi model will be the best of the bunch and with good memory you can do 4400mhz+ without much tweaking (2 dimm only). Are you able to budget in a decent 32gb kit of memory to finish it off?

In that case the info I placed below would likely be your best bet, would you be able to squeeze out enough for a better board at least?

This well and honestly depends on what country you're located in and whether or not you'd be comfortable with getting hardware from aliexpress as I believe they have some far better deals for hardware that would give you much better price/perf. If you're set to the R5 5500 then I'd try to shoot for a slightly better board to pair with it, low-end gigabyte AM4 boards are very temperamental and have only given me issues on both b350 and b450. Try to get as good of a memory kit that's within your budget as the zen 3 APUs can do very high memory clocks in 1:1:1 mode and this makes up for lack of cache compared to the chiplet zen 3 parts.

Semantics aside I believe PBO must be enabled for curve optimizer to take effect, as you are modifying the stock V/F curve of PBO for your chip. There is no inherent reason to disable PBO unless you're extremely temperature constrained in something like a passive system, otherwise adjusting the TDC, EDC and PPT to your liking is a much preferable option to retain performance.