It will need a BIOS update first. The motherboard you listed says it has "AsRock Instant Flash", which appears to be a version of BIOS flashback. This should enable you to update the BIOS through a USB flash drive, without needing to install an older processor first.

At least that's what it appears through some light research. If you can confirm that this is, in fact, a bios flashback function, then yes, you will be able to update the motherboard and use the CPU after the update.

Bios flashing is nothing to be afraid of.

Just avoid pitfalls like using exfat instead of fat32, and trying to use the .zip file instead of decompressing the .bin file.

I seem to remember some bios being able to read exfat, and even accepting the .zip, but I might be misremembering.

it was only the first gen ryzen boards that would not post or boot with unsupported cpu
newer boards can update bios with the cpu that the current bios does not support

it will be fine til you update bios with the cpu installed

If you are buying it from a store, ask if they can update the BIOS. That's the best option and most will do it for f ree to close the sale. If not, be like "ah well I will just have to buy from somewhere that will". They need the sale and will do it

When you buy a board there is no way to know if it supports that CPU out of the box unless you can get the revision number or serial of the board and ask the manufacturer (only they know what BIOS is running on it).

That said, for most modern AMD CPUs the CPUs are usually just ran in "compatability mode" when unsupported meaning that it will still boot, but the CPU is technically unsupported or may lack features. This means that they may have some instability when running or some features may not work properly until you update the BIOS, even if it does boot

Since you are running a 5600x and not a 5600G booting from iGPU I don't think there will be a major issue running it and updating the BIOS, but there is always the remote possibility that it won't boot if Asrock hardcoded it not to boot .

All AM CPUs on the same generation (AM4, AM5, ...) should use similar execution code and run in COMPAT mode first, then full mode. This is supposed to be standard precisely so you can update your BIOS. But again, it depends on how Asrock implemented their BIOS and whether or not they followed guidance.

goto asrock web site. goto support. fine your motherboard (asrock b450m ac r2.0). download the bios... MAKE SURE ITS THE RIGHT ONE.
unzip it.
format a usb stick ntfs.
paste bios file on usb stick.
restart pc with usb stick in.
at logo press del to enter bios page.
look for flash....

easy peasey

Originally posted by HIVEmind:

goto asrock web site. goto support. fine your motherboard (asrock b450m ac r2.0). download the bios... MAKE SURE ITS THE RIGHT ONE.
unzip it.
format a usb stick ntfs.
paste bios file on usb stick.
restart pc with usb stick in.
at logo press del to enter bios page.
look for flash....

easy peasey

to flash bios, usb stick should be formatted fat32

Yah sorry. My bad.

Originally posted by _I_:

Originally posted by HIVEmind:

goto asrock web site. goto support. fine your motherboard (asrock b450m ac r2.0). download the bios... MAKE SURE ITS THE RIGHT ONE.
unzip it.
format a usb stick ntfs.
paste bios file on usb stick.
restart pc with usb stick in.
at logo press del to enter bios page.
look for flash....

easy peasey

to flash bios, usb stick should be formatted fat32

Should I use the MSI pro b550m-VC instead?

Originally posted by Aru8ijjnii:

Should I use the MSI pro b550m-VC instead?

its a better chipset, but weaker vrm config
4(with cooling)+2(no cooling)
~100w to cpu cores

this is <$100 better mix
https://pcpartpicker.com/product/Ytdrxr/asrock-b550-phantom-gaming-4ac-atx-am4-motherboard-b550-phantom-gaming-4ac
ASRock B550 Phantom Gaming 4/ac
6(with cooling)+2(no cooling)
~150 to cpu cores, ~40w to igpu+vrm will be fine since the 5600x has no igpu

Originally posted by _I_:

Originally posted by Aru8ijjnii:

Should I use the MSI pro b550m-VC instead?

its a better chipset, but weaker vrm config
4(with cooling)+2(no cooling)
~100w to cpu cores

this is <$100 better mix
https://pcpartpicker.com/product/Ytdrxr/asrock-b550-phantom-gaming-4ac-atx-am4-motherboard-b550-phantom-gaming-4ac
ASRock B550 Phantom Gaming 4/ac
6(with cooling)+2(no cooling)
~150 to cpu cores, ~40w to igpu+vrm will be fine since the 5600x has no igpu

I'm going with an matx case so this won't fit. Also, I don't plan on overclocking the cpu or the gpu.

turbo/boost on amd cpus can draw about twice their rated tdp
its rated 65w, so ~130w is what it will pull with pbo enabled

Originally posted by _I_:

turbo/boost on amd cpus can draw about twice their rated tdp
its rated 65w, so ~130w is what it will pull with pbo enabled

So will the MSI B550M-VC WIFI be a
better board instead of the original one I suggested?

Darn. I like turbo boost.

no its not better for cpu performance

if you dont want to move to a full atx case

im not a fan of biostar, had to rma a few board for bad flash
Biostar B550MX/E PRO is ~$130
https://pcpartpicker.com/product/98Fbt6/biostar-b550mxe-pro-micro-atx-am4-motherboard-b550mxe-pro
8+2 all with cooling
can give ~200w to cors

but honestly, id look into a bigger case, makes assembly and cable management much easier

Originally posted by _I_:

no its not better for cpu performance

if you dont want to move to a full atx case

im not a fan of biostar, had to rma a few board for bad flash
Biostar B550MX/E PRO is ~$130
https://pcpartpicker.com/product/98Fbt6/biostar-b550mxe-pro-micro-atx-am4-motherboard-b550mxe-pro
8+2 all with cooling
can give ~200w to cors

but honestly, id look into a bigger case, makes assembly and cable management much easier

Do you think msi board will be ok if I don't plan to overclock?