Still haven't built my new computer (though having my old desktop working does help), and I need some advice:

Current specs for new computeR:
* Storage: 1TB NVMe SSD (WD Black), has already been purchased

What I'm looking to run well (ideally 1080p, but can settle for less, and can make do with lower settings; will not be using 4K, as I don't have a display that can handle that):
* Bard's Tale IV
* Pathfinder: Wrath of the Righteos
* Older games like Wizardry 8
* Indie games like Hollow Knight (including Silksong), Ikenfell, Fell Seal: Arbiter's Mark, Celeste

Specs I'm currently looking at:
* CPU: AMD Ryzen 5600g or 5700g (is the 5700g worth the extra expense?)
* GPU: None, going to use integrated graphics (might change when prices become reasonable again)
* RAM: At least 16BG (would 32GB make sense?)
* OS: Some form of Linux. Probably Debian, but I'm open to something like Arch, Fedora, or Gentoo

Other features that I'd like:
* Prefer the computer to be quiet when idle and not too noisy when playing a game
* Would be nice to have modern connectivity options like USB-C, USB 3.2 or later, DisplayPort and/or HDMI
* Computer shouldn't be too hard to open (I like my current desktop's case, with its ability to open without tools)
* Prefer the computer itself not to emit too much light (so I'd rather not have RGB, for example)

So, any advice? I'm particularly interested in which AMD CPU makes more sense, given the significant price difference, and on what sort of motherboard makes sense to pair with it.

Tha main difference between the 5600G and the 5700G is the number of cores. The first has 6 while the latter has 8. The choice depends on whether you are planning to use heavily multithreaded programs. For the above games you mentionned, I think the 5600G should be well enough. It depends if you are planning to play future games with this computer or not. If you want this computer to last long for you and play future demanding games, you may want to go for the 5700G.

One other difference however is that the 5700G has a slightly better GPU, so it might help a bit, but I don't know how better it is, so you'll have to wait for someone else's answer.

For the Ram I think that 16 GB should be enough. Besides, prices are rising again, so I would not invest too much in it now.

For the other features you mentionned, it really depends on the case and the motherboards model and there are a lot of them. Don't go for expensive models, and avoid the RGB madness, that'll save you some bucks. I don't know if the CPUs you mentionned are sold with a fan with them. If not, you may want to invest some money in a 3rd party efficient fan model (Noctua ? Be Quiet ?).

One important thing : don't negligate on your power supply, you don't want to have your computer to catch fire because of a cheap 3rd party model. Since you don't want a graphic card, your computer won't need too much power, so you probably can take a 400W model or maybe even less, not more, unless you are planning to have a separate graphics card later on.

There is absolutely no need to get more than 16GB. Maybe, in the next 10 years developers will move to higher capacity, but for now 16 is just right. According to STEAM 42% of computers have less then 16GB of RAM, and 46% have 16GB. That's a huge piece of the pie for developers to ignore by requiring higher capacity. The 5600g is actually pretty close to the 5700g, but nowhere near the 5600x. The "g" variants have only 16MB of L3 cache, while the "x" has 32MB. If you care about gaming, L3 cache is what you should focus on. That's why when gaming on the 5800X you see next to no differences when compared to the 5600x(they both have 32MB L3 cache). I would say no. The integrated GPU will actually not be that much more powerful. For example this shows only 10% difference.

When it comes to buying, I would say that this year is not the best time for building a new PC. Unless your old system is fried, you should wait at least another year. Not to buy the next generation of CPUs, but for the prices to drop to sane levels.

EDIT: Actually, this just occurred to me, you might be better served getting the 5600x and using the GPU from your old desktop, and eventually buying a GPU when prices normalize, than buying a 5600g/5700g. Any discrete GPU will be better than any integrated GPU.

My old desktop doesn't have a discrete GPU, so that isn't an option.

+1 for the advice to get a good power supply. You can use it in future computer builds as is, the extra efficiency will save you money and a good power supply will be safer for you and your computer components.

Just be sure to read the reviews carefully as there are some dodgy practices going on with companies getting high efficiency ratings then swapping parts later in the actual manufacturing process. That goes for all components of course but especially the power supply which could actually be dangerous.

Oof!

Have you ever seen a modern(ish) game wherein the UI is important in non-native resolution? (e.g. Pathfinder in 720P on a 1080P screen)
Me, I find the loss in sharpness unacceptable. For games with not much UI/HUD on screen it's not as bad... (but I'll always prefer native resolution of course)

16GB will be fine for your needs unless you're in to serious multi-tasking. Assuming you're not going to e.g. Stream, compile code, browse the web, spreadsheet and play games at the same time, with the type of games you play you're not going to need a tonne of RAM.

I can't really help on iGPUs (I'd just by a proper GPU and have done with it, but appreciate that the semiconductor shortage isn't helping). However, if you want to keep it quiet, my suggestion is to get a decent case and slap some 120mm or larger case fans in there to maximise airflow. Or slap a big aftermarket cooler on the CPU.

Apparently, the 5600g actually runs at a higher base frequency than the 5700g, so the 5700g is not strictly better than the 5600g. Because of this, and the price difference, I may go with the 5600g.

It's not just about clock speed. For whatever reason (could be better IPC, could be other design factors), the 5700g generally benchmarks better on single threaded performance than the 5600g. Additional benefits to the 5700g include better onboard graphics (although based on your gaming preferences unclear whether this makes a difference for you) and additional cores/threads (although again, based on your gaming preferences, it doesn't look like you play much that uses multiple threads).

Ultimately, it's about how much money you're prepared to pay for additional performance.

HOWEVER, none of these Ryzen APUs have PCIe 4.0 support. I would be inclined to buy a proper Ryzen chip and a GPU (even if it's just a cheap one) for that feature. Of course, if you're not going for a high end video card of 4.0 NVME drive, it might not be worth it for you.

Yes, AMD decided to take a step back and go with PCIe 3.0 for the G series but at least the graphics card slot now (on the 5000 series) supports 16 channels. Does it matter that it is PCIe 3.0 and not 4.0? A little with the top cards if you stress them, not at all with the low end cards. The real problem children are those mid-range PCIe 4.0 cards that come with only 8 channels on them. No problem if your motherboard AND processor support PCIe 4.0.

QFT.

RAM: Check the density. LESS dense ram is faster (it can parallelize access more). But a single 8GB stick is not just a single 8GB stick if one is [examples] 2x 4GB chips vs the faster 4x 2 GB chips on the stick. It's usually a negligible cost difference for a somewhat noticeable performance difference. But 16 GB's fine if you're not doing heavy virtualization, which, knowing how you work based on posting and chats, I don't think you do... ...except you're using built-in GPU, which does RAM sharing, so you probably should bump to 32 if you can budget for it (or leave room for the bump later).

*sigh* Video cards. I've been wanting to upgrade my Radeon RX 580 for ages... I was hoping the 6000 series would have been it. And then *waves hands at all the mess*. I almost went to Cleveland this weekend because Microcenter had an overpriced 6600 listed as in stock. I only want a 6600!

For noise: Fewer, larger fans will make a quieter system usually. Ensuring the CMOS/OS is set to conserve/throttle will go a long way for noise. Lacking a discrete GPU will also cut a big source of noise. And you're already planning on SSDs, so there goes HDD noise. And cooling fans on the HDDs... I always use stock bundled coolers (because I don't care too much about noise), but people rave that aftermarket ones, in addition to cooling better, are often quieter. I don't have personal experience with it, but I doubt that much "wisdom of the Internet" is wrong.

As for RGB... good luck avoiding them. I hate that crap. And the software to control them when possible is often a pain. Fortunately I'm running Windows, because otherwise my mouse would be an obnoxious glowing flashing mess. (Its software isn't available for Linux). I've heard some people just break off the LEDs [say from fans], but that sounds... dangerous to me. My case's power indicator is so fucking bright (and that perfect "wake you up at night" shade of blue...) that I have to make sure it's off. And then the NICs are still blinking for link/WOL-calls even when I'm off, and I haven't figured any way to get them to stop blinking.

Cases, almost all are tool-less or minimal-tool nowadays. They're quite standardized now, though you can find unusual ones if you look. When I replace my headless Linux box, I need to take careful measurements. It's an ancient Atom micro-ITX case and it fits perfectly on an overhang shelf to my basement.

For which CPU: Your decision may be dictated by which is available. They seem to be quite similar overall, and others have already posted on them.

Correct - aftermarket ones are usually better and quieter. Stock coolers generally have fans around the 90mm mark - decent aftermarket ones are typically 120mm. Simplistically, bigger fans mean you can displace the same amount of air - and provide the same cooling - at a lower RPM (so less noise).

Oh, some of us are quite happy with our 580. Sure raytracing could be nice in the one game I have that supports it but €900 nice? No.
Also, bigger heatsink helps.

Talking about that: The bigger coolers do not fit into all cases. One has to check listed height for cooler and max allowed in case. A sub-$45 cooler should be enough for the 5600G with margin.

Also true. The other thing to consider (especially on a budget board) is VRM cooling. I remember the old AMD FX series - on some motherboards, the VRMs overheated unless you had a fan that blew down into the board - the tower set up ones cooled the CPU very well, but let the VRMs overheat (causing throttling). Happened to me - nightmare to diagnose.