Which of the two M.2 ports is it better to use for OS boot storage device

[huguberhart]

Hello, I would like to ask about configuration of my system. I've searched the ASUS forums and other places, but the general question didn't exhaust my doubts.

I have ASUS Z370-I motherboard. I had two drives in M.2 slots. Samsung 960 Pro 1TB (OS) in the Sata/PCIe slot and a 950 Pro 256GB in the back PCIe only slot.

I've found a deal on a Samsung 980 Pro 1TB (I don't know why I don't buy other drives..) and today, I've replaced the smaller 256GB drive with the 980 model.

Question: Is it worth it to clone OS to the 980 storage device? Is the performance hit gonna "even out" with the 960 due to the only Gen3 slot available on the Z370-I?

Does it matter which M.2 slot/port has the faster drive (other than the added heatsink on one of the slots)?

Thank you

[RAS_3885]

The 960 PRO is PCIe, right?

 

If both M.2 only support PCIe 3.0 then it doesn't matter which drive goes where. You're also spending extra for the 980's Gen4 capability that you won't be able to use, unless it's a really good deal you found.

 

Assuming both slots are 3.0 I wouldn't bother cloning the OS and would just leave it as is.

[--SID--]

980 Pro is a PCI-e4.0 SSD that runs at PCI-e3.0 on your motherboard. There's no performance gain at all when you switch it with the 960 Pro or 950 Pro.

[Alex Atkin UK]

13 minutes ago, --SID-- said:

980 Pro is a PCI-e4.0 SSD that runs at PCI-e3.0 on your motherboard. There's no performance gain at all when you switch it with the 960 Pro or 950 Pro.

The heatsink may be a benefit however.

[--SID--]

10 minutes ago, Alex Atkin UK said:

The heatsink may be a benefit however.

At 3.0 speed? I don't think so.

[huguberhart]

Thank you for the replys. I've initiated the 980 drive. In Samsung Magician there is info, that the driver used for NVMe is Microsoft. I've run the built in bench. Here are the results:

The heatsink seems to be useful for the 960 device. I have a NCase M1 and the drive on the back has some space. I have to get a low profile heatsink.

 

[Alex Atkin UK]

17 hours ago, --SID-- said:

At 3.0 speed? I don't think so.

Yes, because under heavy load the controllers can still thermal throttle.

Its not necessarily the throughput but how long you're pushing that throughput.  Also with random read/writes, you're not limited by PCIe but by the NAND and controller.

[Alex Atkin UK]

8 hours ago, huguberhart said:

Thank you for the replys. I've initiated the 980 drive. In Samsung Magician there is info, that the driver used for NVMe is Microsoft. I've run the built in bench. Here are the results:

The heatsink seems to be useful for the 960 device. I have a NCase M1 and the drive on the back has some space. I have to get a low profile heatsink.

 

That pretty much confirms it, the random IOPS are so close I doubt you'd tell the difference between them for an OS drive.