Question Need advice for CPU + new Motherboard upgrade [BIOS related]


Diamond Member
Jan 29, 2005
I'll be upgrading to a Ryzen 7 5800X this week, with a new Motherboard; the ASUS B550-Plus.

I'm aware of two things:

1) The B550 might not have the proper BIOS version (out-of-the-box) to accommodate the new CPU.
2) If that's the case, I'll need to update the BIOS (obviously).

Now, I've updated BIOSes before, I'm not new to that.

However, what's 'new' for me is the possibility that - right from the start - the Motherboard's BIOS might not be ready for the CPU.

So, questions:

Do I have to just install and plug and powerup the new system with JUST the Motherboard and NO CPU installed in the socket, and then Flash the BIOS without a CPU installed?
2) Or, should I actually still physically install the new CPU, plug in everything, powerup the new system and cross my fingers that the house won't burn?

In essence, I'm simply not sure on how to proceed in the event that I need to flash the BIOS to make the Motherboard compatible with the new CPU. If I have to install the CPU anyway, or if it would be "safer" to just flash the BIOS without the CPU installed (which I've never had to do before). Actually, I don't even know if Motherboards CAN even start up or access their BIOS menus without a CPU installed (or if it's safe for the Motherboard to do that without a CPU installed).

I'd appreciate advice about this, please.

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Reactions: sonus00


Memory and Storage, Graphics Cards
Super Moderator
Sep 13, 2008
I would put the system together in full, including CPU, first. And don't forget a supported cooler! (5800X will not come with one) If the BIOS the board comes with does not yet support the 5000 series, chances are it won't post at all. Luckily, you can update the BIOS on your B550 board without a supported CPU, without even booting anything, by using the BIOS flasback button on the motherboard. Simply follow the instructions for the BIOS flashback.
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Reactions: Zenoth


Senior member
Mar 21, 2007
Unless you purchase a board that's been sitting on a shelf for a LONG time the board should have a BIOS compatible with the 5800x. 5000 series CPUs have been out a while.