is this a 3rd gen CPU?

[Edward78]

AMD Ryzen 9 5900X 12-core, 24-Thread Unlocked Desktop Processor

Google says 4th, but I cam't find a gen 4 board??

[Eigenvektor]

It's AMD's Zen 3 architecture, which is technically 4th gen.

Zen, Zen+, Zen 2, Zen 3

 

You'd typically pair that with B550 or X570 motherboards. Older boards can be compatible with a BIOS update: https://thunderboltlaptop.com/list-of-zen-3-compatible-motherboards/

[Moonzy]

Ryzen 5000, which is ryzen 4th gen, based on zen 3 architecture

 

So...

[Bombastinator]

1 hour ago, Edward78 said:

AMD Ryzen 9 5900X 12-core, 24-Thread Unlocked Desktop Processor

Google says 4th, but I cam't find a gen 4 board??

AMD doesn’t do motherboards the way intel does. Few do really.  Intel makes a new socket for each chip design so there will only be 2 generations of chip per board.  Am4 has been the AMD socket for many years now.  I’m not sure when it started, but x370 I believe was am4. This is not to say that a, say, b550 will handle any chip designed for am4 with no trouble. There are other issues such as whether the chip in question is still even included in standard bioses. If one had the right bios I suspect one would likely work ok though.  I don’t think rysen3 chips were ever included in x370 bioses and unless a board has the bios to run a given chip, it can’t.  Am4 is reaching EOL though and I expect a new socket for ddr5. I don’t know if it will be am4+ or am5.  Someone else may though.

[CryingWimp]

AMD screwed this up when they called the second Ryzen gen "Zen+". So then 3rd gen became Zen2, and now 4th is Zen3 

 

The 5900x is the newest. You want a 500 series board, either B550 or x570. With such a high end CPU, consider a decent quality board aswell.

[Middcore]

47 minutes ago, CryingWimp said:

AMD screwed this up when they called the second Ryzen gen "Zen+". So then 3rd gen became Zen2, and now 4th is Zen3 

 

Also when they skipped 4000 series part numbers (except for APU's consumers couldn't buy) and went right to 5000.

[maartendc]

13 hours ago, Edward78 said:

AMD Ryzen 9 5900X 12-core, 24-Thread Unlocked Desktop Processor

Google says 4th, but I cam't find a gen 4 board??

The people above here are correct.

 

In short, you just need an "AM4" motherboard (which is the name of the CPU socket), preferably with a X570 or B550 chipset. (X470 and B450 chipset motherboards might also work, but those are older / last gen and might need a BIOS upgrade).

 

For a Ryzen 5900X, get the best X570 motherboard you can afford. Those things run hot, and you can use the extra power delivery (VRM's) on those more expensive boards.

[Bombastinator]

People are still annoyed about the whole “+” thing years later. To make it more fun the marketing people give AMD apus an additional number bump so 3xxx series apus actually have 2xxx series CPUs. It’s obnoxious. AMD fixed it and then momentarily tried to go back. It’s why the only 4xxx AMD parts are all apus and there is a 5xxx series now.  It seems to me that when various people disparage lawyers they are usually talking about the crimes of marketers and merely attributing them to lawyers.

[Eigenvektor]

1 hour ago, maartendc said:

For a Ryzen 5900X, get the best X570 motherboard you can afford. Those things run hot, and you can use the extra power delivery (VRM's) on those more expensive boards.

High-end B550 should work just as well. X570 only makes sense if you need the extra PCIe 4.0 lanes, imho.

[Middcore]

1 minute ago, Eigenvektor said:

High-end B550 should work just as well. X570 only makes sense if you need the extra PCIe 4.0 lanes, imho.

 

Tend to agree. Compared to the average middle of the road B450 board that had 4+2 VRM, many B550 boards seem really "over-engineered."  No concerns about clean power delivery. 

[CryingWimp]

400 series isnt officially supported, as beta bios version only.

 

Thats why tons of people have bugs