M.2 slots on ASUS z790…has 3…..all are PCIe 4.0 is one “faster”?

[johnrr68]

Here is my dilemma.

My ASUS Z790 Prime P Mobo has Three M.2 slots

Here are the specs:

Intel® 13th and 12th Gen processors:

M.2_1 slot (Key M), type 2242/2260/2280/22110 (supports PCle 4.0 x4 mode)

Intel® Z790 Chipset:

M.2_2 slot (Key M), type 2242/2260/2280 (supports PCle 4.0 x4 mode)

M. 2_3 slot (Key M), type 2242/2260/2280/22110 (supports PCle 4.0 x4 & SATA modes).

Slots 1 and 2 are very close if not under parts of the RTX 4080 vid card…and the heat involved.

Slot 3 is perfect and away from the card and additional heat sources…even allows for the attachment of the included ASUS M.2 Heat Sink.

But this part of the specs on slot 3 scares me.  “(supports PCle 4.0 x4 & SATA modes). The…&SATA mode.

Does this make that port actually slower overall and hurts bandwidth?? Or all three ports will perform the same with a standard 2280 M.2 drive??

Planning on a 2 TB Samsung NVMe 980 Pro as my boot drive.

[LeDoyen]

From the manual :

Intel® 13th & 12th Gen Processors
M.2_1 slot (Key M), type 2242/2260/2280/22110 (supports PCIe 4.0 x4 mode)

Intel® Z790 Chipset
M.2_2 slot (Key M), type 2242/2260/2280 (supports PCIe 4.0 x4 mode)
M.2_3 slot (Key M), type 2242/2260/2280/22110 (supports PCIe 4.0 x4 & SATA modes)

 

The top one is connected directly to the CPU PCIE lanes, and the two others go to the PCH.

In practice they are all PCIE4, but it's usually better to go direct to the CPU for your main drive as the bandwidth will not be shared with other devices on the motherboard.

The very last one can use both modes, PCIE or SATA, so if you wanted to use a SATA M.2 drive for some odd reason, it would work only on the third slot. the two other ones are purely PCIE.

[johnrr68]

@LeDoyenThe location of that preferred slot….#1 is right next to the vid card which will be a RTX 4080

Do you see a possible heat issue?

Asus does include a heat sink for the M.2

Case will have 7 total QL 120s and 3 ML 120s and 3 QL 120s in push pull on the Cappelix H 150 i

13 fans total…think it will have very good airflow

Corsair 5000d airflow case

Edited February 3 by johnrr68

[LeDoyen]

It should work just fine with the heatsink. nand memory works best when a little warm anyway. Better for longevity.

it may be challenging when doing masses of file transfers, as is always the case with pcie 4, but it's not something we do often, least of all when gaming.

it's hard to predict temps, so it's just best to test for yourself. as long as you remain under throttling territory (usually under 70 -75°c), it will be ok.