Ryzen 5600G and B550 Motherboard - Question about PCIe 4.0 M.2 Slot

[flipped_bit]

Putting together a new build

 

I know the 5600G only supports PCIe 3.0, but the top M.2 slot on my motherboard (Asus B550-F Wi-Fi) is PCIe 4.0. 

 

Will my PCIe 3.0 NVMe SSD work in this slot at 3.0 speeds, or will the CPU not work with it at all?  I'd hate to have to use the 2nd (chipset) M.2 slot.

 

I've read PCIe 4.0 is backwards compatible, so I hope it will be fine.

 

Thanks.

[bmx6454]

yes, it will work, but be limited to the 3.0 speeds.

[Eighjan]

4 minutes ago, flipped_bit said:

Putting together a new build

 

I know the 5600G only supports PCIe 3.0, but the top M.2 slot on my motherboard (Asus B550-F Wi-Fi) is PCIe 4.0. 

 

Will my PCIe 3.0 NVMe SSD work in this slot at 3.0 speeds, or will the CPU not work with it at all?  I'd hate to have to use the 2nd (chipset) M.2 slot.

 

I've read PCIe 4.0 is backwards compatible, so I hope it will be fine.

 

Thanks.

What you plug into any interface slot on a motherboard will work at the highest common speed; in this case, a PCI-e 3.0 SSD can only work at the CPU's top speed (3.0).

 

*Edited.

[flipped_bit]

3 minutes ago, Eighjan said:

What you plug into any interface slot on a motherboard will work at the lowest common speed

One reason I am concerned about this is because I specced out an Intel build as well with a 10600K on a Gibabyte B560M Aorus Pro AX and the spec page for the motherboard says the CPU M.2 socket it only compatible with 11th gen processors, not 10th gen.  Maybe they meant to say the 4.0 speed is only compatible with 11th gen, but a 3.0 speed would work fine?  Anyway, it put a doubt in my mind even though I'm going with an AMD build (since I can't find the 11400 anywhere).

 

Here is the spec page, BTW:

 

https://www.gigabyte.com/Motherboard/B560M-AORUS-PRO-AX-rev-1x/sp#sp

[YoungBlade]

3 minutes ago, flipped_bit said:

One reason I am concerned about this is because I specced out an Intel build as well with a 10600K on a Gibabyte B560M Aorus Pro AX and the spec page for the motherboard says the CPU M.2 socket it only compatible with 11th gen processors, not 10th gen.  Maybe they meant to say the 4.0 speed is only compatible with 11th gen, but a 3.0 speed would work fine?  Anyway, it put a doubt in my mind even though I'm going with an AMD build (since I can't find the 11400 anywhere).

 

Here is the spec page, BTW:

 

https://www.gigabyte.com/Motherboard/B560M-AORUS-PRO-AX-rev-1x/sp#sp

There's an important difference there: 11th gen also has 4 additional PCIe lanes vs 10th gen. That's why top slot M.2s are wonky on 500 series Intel boards.

 

The 5600G has the same number of lanes, just running at 3.0 speeds, so the slot will work. It just can't go at Gen 4 speeds.

[flipped_bit]

1 minute ago, YoungBlade said:

There's an important difference there: 11th gen also has 4 additional PCIe lanes vs 10th gen. That's why top slot M.2s are wonky on 500 series Intel boards.

 

The 5600G has the same number of lanes, just running at 3.0 speeds, so the slot will work. It just can't go at Gen 4 speeds.

Ahh I see!  I appreciate your and the other responders answers - I will go ahead with this build with confidence   I don't need the 4.0 speeds at all, just wanted to make sure the top M.2 slot would work with the 5600G.

[Dch48]

There have been numerous problems reported with the combination of the 5600G CPU and a B550 motherboard. From different manufacturers as well. The other AMD chipsets seem to be fine.  Even if it says compatible, it may not be.

[edgardorgz]

I have a similar question, does an SSD PCIe 4.0 works with the ryzen 5 5600g?

[Chiyawa]

1 hour ago, edgardorgz said:

I have a similar question, does an SSD PCIe 4.0 works with the ryzen 5 5600g?

It should be, but it'll run on PCIe 3.0 speed.