new motherboard or not

[CommuteTooFar]

I have decided to buy a new prooessor upgrading from a Ryzen 5 2600X to a Ryzen 7 3700X.  Hexacore to Octacore. Better IPC and faster clock.
I will buy new memory PC4-25600.  3200Mhz is more appropriate than my current 2933Mhz stuff.

The question is about the motherboard.  I could keep the old B350 Tomahawk Arctic board which dates from Ryzen 1000 series. Just need to upgrade the bios and the new stuff will work.

On the other hand as everything else is new I could buy the uptodate equivalent, B450 Tomahawk Max. AFAIK there is not much difference between the B350 and B450 chipsets.
The main advantagge the Max board has is a 32MB bios versus a 16MB one. The allows the Max to support every current AM4 CPU or APU. The Artic can only support older chips with the current bios I use. If I upgrade to a Ryzen 3000 chip I will lose support of the older chips and other functions of the motherboard.

I have considered x570 boards but they are expensive. I have no use for PCI-e 4.0. And the fan is a point of failure.

[CommuteTooFar]

probably not.  There is no real advantage of b450 over b350

Precision boost and extended frequency range (XFR).   I'm not interested in overclocking.
Store MI.  A system to relocate less used files to slower hard drives.

A few people online are saying memory support is improved by b450. This does not make sense to me.  On Ryzen memory compatibility is a function of the processor and motherboard quality not the chipset. Both the b350 and b450  tomahawks are mid cost boards.  Premium chipsets are x370, x470 and x570.  Economy chipset is A320.
There is supposed to be a b550 chipset coming in a few months time.

[CommuteTooFar]

Certainly.  I decided to upgrade an even older computer as well. So I did buy the new 450 motherboard.