Question ASRock Taichi Lite Z790, Gigabyte 4080 Super and M2 drive (Gen5) question on config

[domerdel]

I received my ASRock motherboard and other components arriving over the weekend to start my build. Upon reviewing the instruction manual, if

1. M2 2_1 is used, then PCIe #1 is downgraded from PCIe 5.0x16 down to 5.0x8. or...
2. If I use M2 2_2 then my Gen5 M2 drive gets bumped down from Gen5x4 to Gen4x4 (128Gbs to 64Gbs).

Where will I see the biggest difference between scenario 1 vs. 2 above? Or is scenario 2 the safe bet? (just that I slightly overpaid for Gen5 when only getting Gen4 2280 speeds) ?

Components:
ASRock Taichi Lite Z790
Gigabyte 4080 Super
Crucial T700 Gen5 1TB

 

[35below0]

You have PCIE2, which is also PCIe 5.0 x16. That should run your 4080 if you use M2 2_1 for the Crucial NVMe.

Right? I'm not sure, but the mobo specs indicate this.

Otherwise, you are correct. Using the M2 2_2 will allow only gen 4 speed.

 

[domerdel]

You have PCIE2, which is also PCIe 5.0 x16. That should run your 4080 if you use M2 2_1 for the Crucial NVMe.

Right? I'm not sure, but the mobo specs indicate this.

Otherwise, you are correct. Using the M2 2_2 will allow only gen 4 speed.

There's a catch. If M2_1 (Gen5x4) is in use, then PCIe #2 is entirely disabled. I'm trying to figure out where I'll see the lesser of two evils (my gut tells me Scenario 2)

 

[35below0]

If M2_1 is occupied, PCIE1 will downgrade to x8 mode.
If PCIE2 is occupied, M2_1 will be disabled.
M2_1 and M2_2 cannot be populated simultaneously.

Quite a catch 22 actually, yes.

You have to choose between downgrading the PCIE1 slot from 16x to 8x
or
downgrading your NVMe drive performance from gen 5 to gen 4.

Sticking the Crucial into M2_2 is the lesser of two evils.

 

[domerdel]

If M2_1 is occupied, PCIE1 will downgrade to x8 mode.
If PCIE2 is occupied, M2_1 will be disabled.
M2_1 and M2_2 cannot be populated simultaneously.

Quite a catch 22 actually, yes.

You have to choose between downgrading the PCIE1 slot from 16x to 8x
or
downgrading your NVMe drive performance from gen 5 to gen 4.

Sticking the Crucial into M2_2 is the lesser of two evils.

That's where my gut is leaning.