Looking to buy WD Black SN750 and have a few questions..

[CWellB]

Hi everyone, looking to pickup https://www.amazon.ca/Black-SN750-NVMe-Internal-Gaming/dp/B07M64QXMN?th=1

 

SN750 1tb nvme drive today but I have some questions I am hoping to consult the forum about..

 

My motherboard is Asus B550f Rog Strix https://www.asus.com/Motherboards/ROG-STRIX-B550-F-GAMING/specifications/

Under the specs it lists as an additional note.

 

* Share bandwidth with PCIe3.0 x1_1, PCIe3.0 x1_2, PCIe3.0 x1_3
* When the M.2_2 Socket 3 is populated , SATA6G_5/6 ports will be disabled.

 

Could anyone possibly shed some insight on what all this means for me? I only see 2 sockets on the board for these types of drives, where is this socket 3? 

Does this bandwidth share mean anything that I need to concern myself with, when adding a second nvme drive in the future or any other interactions I should be aware of? 

 

Thanks for any insights.

[Hairless Monkey Boy]

20 minutes ago, CWellB said:

PCIe3.0 x1_1, PCIe3.0 x1_2, PCIe3.0 x1_3

I only see 2 sockets on the board for these types of drives, where is this socket 3? 

These refer to the PCIe x1 slots of which you have 3. Not the M.2 slots.

 

20 minutes ago, CWellB said:

SATA6G_5/6 ports will be disabled

Does this bandwidth share mean anything that I need to concern myself with

This will only matter to you if you have drives plugged into those SATA ports.

[CWellB]

2 minutes ago, HairlessMonkeyBoy said:

These refer to the PCIe x1 slots of which you have 3. Not the M.2 slots.

 

This will only matter to you if you have drives plugged into those SATA ports.

Thanks for that clarification.

 

So does this mean that using the m2_2 slot will interfere only with those SATA ports and will not interfere with the pcie x16 slot ? I am a bit confused as I had read elsewhere that populating the m2_2 slot on a board causes it the share bandwidth with the pcie x16 slot (gpu)

[Viper9]

The WD Black SN750 is using the PCIe lanes so the SATA ports won't be disabled. 

[CWellB]

Just now, Viper9 said:

The WD Black SN750 is using the PCIe lanes so the SATA ports won't be disabled. 

Only in those specific cases? and the difference is with my board, it doesn't use the PCIe lanes and instead disables the SATA ports is this correct?

[Hairless Monkey Boy]

2 minutes ago, CWellB said:

So does this mean that using the m2_2 slot will interfere only with those SATA ports and will not interfere with the pcie x16 slot.

Correct. 

 

4 minutes ago, CWellB said:

I am a bit confused as I had read elsewhere that populating the m2_2 slot on a board causes it the share bandwidth with the pcie x16 slot (gpu)

False. The GPU PCIe x16 slot does not share bandwidth at all. The lower x16 physical slot shares banndwidth with the 3 x1 slots. Not something you have to worry about.

 

3 minutes ago, Viper9 said:

The WD Black SN750 is using the PCIe lanes so the SATA ports won't be disabled. 

This is false. The manual specifically states that the SATA ports are disabled when the slot is populated. So it it doesn't matter the type of drive.

[Hairless Monkey Boy]

3 minutes ago, CWellB said:

Only in those specific cases? and the difference is with my board, it doesn't use the PCIe lanes and instead disables the SATA ports is this correct?

When the m.2_2 slot is populated, the PCIe lanes from the chipset that where being used for SATA ports 5/6 are instead used for the PCIe or SATA mode M.2_2.

[CWellB]

7 minutes ago, HairlessMonkeyBoy said:

When the m.2_2 slot is populated, the PCIe lanes from the chipset that where being used for SATA ports 5/6 are instead used for the PCIe or SATA mode M.2_2.

Ok thanks for this.

 

My understanding now is that I could populate both m2 slots with nvme and my gpu will be unaffected. My only loss is 2 SATA ports.

 

Thanks, I feel confident to go buy the drive.

[Hairless Monkey Boy]

It's X570 instead of B550, but this Gamer's Nexus chipset map might make things a little easier to understand. You can see that the pink line shows all of the different ways that motherboard manufacturers can choose to allocate the PCIe lanes coming from the chipset. Using them for different numbers of PCIe slots or some of them for SATA or a mix of each with different options for the end user.

 

[CWellB]

3 minutes ago, HairlessMonkeyBoy said:

It's X570 instead of B550, but this Gamer's Nexus chipset map might make things a little easier to understand. You can see that the pink line shows all of the different ways that motherboard manufacturers can choose to allocate the PCIe lanes coming from the chipset. Using them for different numbers of PCIe slots or some of them for SATA or a mix of each with different options for the end user.

 

Ok this made it very clear, thank you very much for this!

[Viper9]

34 minutes ago, HairlessMonkeyBoy said:

This is false. The manual specifically states that the SATA ports are disabled when the slot is populated. So it it doesn't matter the type of drive.

 

If he's using slot M.2_1 the SATA ports 5 and 6 won't be disabled.

 

[Hairless Monkey Boy]

1 minute ago, Viper9 said:

If he's using slot M.2_1 the SATA ports 5 and 6 won't be disabled.

Yeah I know... He was specifically asking about M.2_2. And he intends to use both M.2 slots. Check out the chipset map if you are still confused with how this all works, and let me know if you have any questions.