[SOLVED] Question About Motherboards and M.2 Slots

[julienruc]

Hi all,

I'm in the market for a secondary SSD to store my games in. I will be purchasing the cheapest 1TB SSD that's available to me as I won't be storing anything important in it. Right now, that's a 1TB M.2 stick which is great because I won't need to work with cables.

I did however have a quick read of the motherboard manual before I commit and buy anything and noticed this line: "*4 When the M.2_2 is occupied by M.2 device, PCIe x16_1 will run at x8 mode. "

Seeing as this is the top x16 PCIe lane where my graphics card is installed. Adding a second M.2 to my system will reduce the speed of this PCIe lane and therefore reduce the speed at which my GPU is operating?

Will this slow down my GPU? Is there some information I missed somewhere perhaps?

Current Setup is as follows:

• GPU currently seated on PCIe 16_1
• USB expansion slot on PCIe 1_3
• SX8200 Pro on M.2_1 (disabling Sata 5 & 6)
• Seagate and WD 2TB HDDs are slotted on Sata 1 & 2

My Build:
Ryzen 7 2700X
Noctua NH-D15S
ROG Strix B450-F Gaming
Gigabyte RTX 3080 10GB Aorus Master
G.Skill Trident Z RGB 2x8GB 3200Mhz
Adata SX8200 Pro 512GB (in M.2 slot 1 as per manual)
Seagate Barracuda 2TB ◾ WD Blue 2TB (in Sata slot 1 & 2 as per manual)
NZXT AER 140mm & Hue+ ◾ Noctua NF-A12x25 PWM
Super Flower Leadex III Gold ARGB 850w
Fractal Design Meshify C Dark TG

This is where I found the line (Note section):
https://rog.asus.com/motherboards/rog-strix/rog-strix-b450-f-gaming-model/spec

Motherboard Manual:
https://dlcdnets.asus.com/pub/ASUS/...ING/E14401_ROG_STRIX_B450-F_GAMING_UM_WEB.pdf

 

[Eximo]

You can test this by limiting the PCIe slot to 8x in the BIOS, or plugging any PCIe device into your other x16 slot (which is effectively what the M.2 drive is doing)

It would probably be game specific depending on how much bandwidth the GPU needs, and the 3080 is pretty beefy, so it is possible if you were running a 4K monitor or the like.

 

[Lutfij]

*REST OF BUILD IN SIGNATURE
We encourage people to post their specs in the body of the threads since sig space specs can and will change over time. making this thread and it's relevant solution moot useless to the user in the same problem as you are now(in the future for them).

Your specs are...
Ryzen 7 2700X
Noctua NH-D15S
ROG Strix B450-F Gaming
Gigabyte RTX 3080 10GB Aorus Master
G.Skill Trident Z RGB 2x8GB 3200Mhz
Adata SX8200 Pro 512GB ◾ Seagate Barracuda 2TB ◾ WD Blue 2TB
NZXT AER 140mm & Hue+ ◾ Noctua NF-A12x25 PWM
Super Flower Leadex III Gold ARGB 850w
Fractal Design Meshify C Dark TG

As for the question, yes the GPU will be running at x8 (lanes)speeds but the performance dip will be minimal.

 

[julienruc]

We encourage people to post their specs in the body of the threads since sig space specs can and will change over time. making this thread and it's relevant solution moot useless to the user in the same problem as you are now(in the future for them).

I never considered my threads being used by people in the future - I'll be sure to mention it for all my future threads.