Some advice please on AMD B650E / X670E pcie lanes and storage (M.2 and SATA)

[Desktopstu]

Hi knowledgeable people. Not sure if this is best posted in the storage or motherboard forum, starting here under motherboard to see what comes back.

Im after some clarification on the Asus X670E Tuf motherboard M.2 arrangements. There are four M.2 slots on this board, M.2-1 above the primary graphics PCIe slot thats compatable with Gen 5 linked to the CPU. M.2-2 next to the PCIe 4x slot compatable with Gen 4 also shares with the 4 SATA and is linked to the chipset. M.2-3 and M.2-4 that are back to back below M.2-2 one of these is linked to the cpu, the other to the chipset, both of these are Gen 4.

Am i correct in my assumption that none of these will take bandwidth from the primary graphics PCIe slot or indeed any other PCIe slot? If I loaded up all 4 M.2 slots I would lose SATA entirely?

It states the following in the manual:

AMD Ryzen™ 7000 Series Desktop Processors:
- M.2_1 slot supports PCIe 5.0 x4 mode M Key design and type 2242/2260/2280
storage devices.
- M.2_3 slot supports PCIe 4.0 x4 mode M key design and type 2242/2260/2280
storage devices.
• AMD X670 Chipset:
- M.2_2 slot supports PCIe 3.0 x4 & SATA modes M key design and type
2242/2260/2280/22110 storage devices.
- M.2_4 slot supports PCIe 4.0 x4 mode M key design and type 2242/2260/2280
storage devices.
• M.2_2 slot shares bandwidth with SATA6G_1&2. When M.2_2 runs at PCIe x4 mode,
SATA6G_1&2 will be disabled.

Thank you in advance.

 

[TheLostSwede]

Only mistake you made was the the M.2_2 is PCIe 3.0, not PCIe 4.0. Also, you only lose SATA 1 and 2, not all four SATA ports, when it's in use. If you use a x2 NVMe drive, you can still use the SATA ports, but those kind of drives are not common.
Otherwise it appears that nothing else is sharing bandwidth on that board.

How I wish all motherboard makers could go back to having block diagrams in their manuals, it would make these things so much easier to spot.

 

[Desktopstu]

Only mistake you made was the the M.2_2 is PCIe 3.0, not PCIe 4.0. Also, you only lose SATA 1 and 2, not all four SATA ports, when it's in use. If you use a x2 NVMe drive, you can still use the SATA ports, but those kind of drives are not common.
Otherwise it appears that nothing else is sharing bandwidth on that board.

How I wish all motherboard makers could go back to having block diagrams in their manuals, it would make these things so much easier to spot.

Thank you for the clarification, its much appreciated.

Only mistake you made was the the M.2_2 is PCIe 3.0, not PCIe 4.0. Also, you only lose SATA 1 and 2, not all four SATA ports, when it's in use. If you use a x2 NVMe drive, you can still use the SATA ports, but those kind of drives are not common.
Otherwise it appears that nothing else is sharing bandwidth on that board.

How I wish all motherboard makers could go back to having block diagrams in their manuals, it would make these things so much easier to spot.

I note the manual shows that both the PCIe5 16x slot and the M.2-1 gen 5 are both linked to the cpu. Does this mean that if I was to install a Gen 5 graphics card (when they are vailable) and a Gen 5 M.2 this would impact the bandwidth of the graphics card?

It states the following in the manual:

AMD Ryzen™ 7000 Series Desktop Processors*
1 x PCIe 5.0 x16 slot
AMD X670 Chipset
1 x PCIe 4.0 x16 slot (supports x4 mode)
1 x PCIe 4.0 x4 slot

 

[TheLostSwede]

I note the manual shows that both the PCIe5 16x slot and the M.2-1 gen 5 are both linked to the cpu. Does this mean that if I was to install a Gen 5 graphics card (when they are vailable) and a Gen 5 M.2 this would impact the bandwidth of the graphics card?

No, the CPU has 16+4+4+4 PCIe 5.0 lanes.

AMD Zen 4 & Socket AM5 Explained: PCIe Lanes, Chipsets, Connectivity

There has been a fair bit of confusion about AMD's upcoming AM5 platform when it comes to connectivity and we're going to break things down and explain what the difference is between the B650 and X670 boards. We're also going to cover the processor connectivity, since that's an integral part of...

www.techpowerup.com

 

[kapone32]

Thank you for the clarification, its much appreciated.



I note the manual shows that both the PCIe5 16x slot and the M.2-1 gen 5 are both linked to the cpu. Does this mean that if I was to install a Gen 5 graphics card (when they are vailable) and a Gen 5 M.2 this would impact the bandwidth of the graphics card?

It states the following in the manual:

AMD Ryzen™ 7000 Series Desktop Processors*
1 x PCIe 5.0 x16 slot
AMD X670 Chipset
1 x PCIe 4.0 x16 slot (supports x4 mode)
1 x PCIe 4.0 x4 slot

With AMD unless you go with 2 Pcie x16 lanes running at x8. That would mean they are connected to the CPU. The board you are looking at has the 2nd PCie and 3rd slot wired to the chipset. You want to have your fastest storage in the first slot. One thing about chipsets on AM4 and AM5 are that the more you add the hotter it gets. BTW Pcie 5.0 x 8 has the same bandwidth as 4.0 x16 so it is right now a nothing burger anyway. The advantage is having more 5.0 drives available to you. On my X670 E Strix there are 3 5.0 slots connected to the CPU.

 

[Desktopstu]

With AMD unless you go with 2 Pcie x16 lanes running at x8. That would mean they are connected to the CPU. The board you are looking at has the 2nd PCie and 3rd slot wired to the chipset. You want to have your fastest storage in the first slot. One thing about chipsets on AM4 and AM5 are that the more you add the hotter it gets. BTW Pcie 5.0 x 8 has the same bandwidth as 4.0 x16 so it is right now a nothing burger anyway. The advantage is having more 5.0 drives available to you. On my X670 E Strix there are 3 5.0 slots connected to the CPU.

Im thinking about using a gen 5 gpu in the new year and using a gen 5 m.2 in the M.2-1 slot. But in doing so I wanted to avoid impacting the graphics card slots bandwidth. I would also like to use some of the Gen 4 M.2 slots and also the sata but not at the expense of the graphics card slot PCIe lanes preferably.