AW 15R2: Why is my GTX 980m running half the bandwidth -i.e. 8x speed

Hi,

My GTX 980M is running at x8 speed instead of x16. It's running W7 and have m.2 and mechanical hard drive.. is having m.2 drive causing conflict with PCIE x16 bandwidth??

Also, it's booting legacy mode--does booting in UEFI matter?

 

Curious, where are you seeing that it's running at 8x?

 

Gpuz or hwinfo. If you have gtx980m, can you check the pcie speed?

 

My 17 R3 says the same.

 

@altecX Thanks for the reply. When you say the same, you mean yours also shows as running at X8 speed instead of x16? I guess it was not meant to run at a full speed?

 

Question...
Does it also say PCI-E 1.1?
This is strange and I have never noticed this before.

EDIT: When running it switches over to PCI-E 3.0 but still remains on x8.

I guess it is a limitation on the available lanes.

 

same here, I never noticed it before while I have looked at that data I thought. Not sure why this is. Not that it matters with these GPU's.

 

What do you mean? Doesnt that mean less bandwidth?

 

The GPU in the 15 / 17 has always ran at a max of PCIe 3.0 x8. Here are some examples from notebookcheck's reviews. The difference between x8 in x16 for these GPUs, as rinneh said, is negligible.

Spoiler: 15 R1 GTX 970m

Spoiler: 15 R1 R9 m295x (in idle)

Spoiler: 17 R3 GTX 980m (applies for 15 R2 as well)

 

Awesome! Thanks for clearing that up @Game7a1

 

The 980M doesnt need all the bandwidth. Even the most high end cards barely lose performance on even PCI express 4X (Linustechtips made a video about that).

PCI express 2.0 x16 is the same as 3.0 x8. One of my PC's is still a sandy bridge based CPU which only supports PCI express 2.0 and I dont lose any bandwidth with my 970GTX in that machine which is a faster GPU than the 980M.

 

Correct. As long as its not hurting the GPU's performance though it shouldn't cause any issue.

 

Awesome! Thanks for clearing this up.

 

Correct me if I'm wrong but I think I read somewhere that 16x to 1x on a current gen 980 was a difference of like 5fps max. Hard to believe but that's what the graphs showed on that site. (don't have the link sorry)

 

i come here for the same question .... nothing to do if i want to change the x8 for x16 ?

 

no, that's the number of available lanes on the motherboard, don't worry about it, the difference in performance is neglible.

Only when you need more lanes like for an NVMe SSD and Dual GPUs in SLI does one need more lanes otherwise the card might drop to 4x even.