Question Caveats of using Ryzen 4750G with MSI B550 UNIFY

[MaheshMP]

Hello,

MSI B550 UNIFY Board has total four M2 slots. 1st is directly coupled with CPU, 2nd and 3rd M2 slots actually share PCI-E 4.0 x 16 bandwidth. If I put SSD in any of these M2 slots, PCI-E slot brought down to x8 mode. This is fine as long as there is graphics card installed in PCI-E x 16 slot.

I just wanted to couple Ryzen 4750G (processor with CPU graphics) with MSI B550 UNIFY / UNFY-X and will not using any discrete graphics card.
Will this disable two middle M2 slots ? Because there are total 16 lanes available for CPU built-in graphics and i am not sure if built-in VEGA CPU graphics will run with x8 and allows SSDs to run in both M2 slots with x4 and x4 mode coupled to CPU?
This will be applicable to B550 Arous master as well

I hope question is clear?

Many thanks in advance.

Mahesh.

 

[rgd1101]

1)apu on have x8 for gpu
2)middle 2 m.2 could use chipset
edit. from the manual look like it will be x4 each on the middle 2

 

[MaheshMP]

Ok, 4750G is desktop APU which actually have 24 PCI lanes, 16x for graphics, 4x reserved for 1st M2 slot and 4x for chipset connectivity
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There is chipset mode and CPU mode available with mobo bios which allow us switch SSD cnnectivity to either CPU or chipset. With chipset it runs with x2 mode and with CPU it runs with x4 mode
Above is true when we use non graphics processor like 3700 x etc
What will happens when I use Ryzen 4750G? and not use any discrete graphics card? will i get same functionality?