SLI GPU's set to 8x and 4x Native?

[TRITIUMNITR0X]

Hey all, 

 

Either I'm having a complete brain fart about compatability, or some unknown settings are forcing my GPU's to lock at 8x and 4x Native PCIE speeds. 

 

If someone can shed some light on why the GPU PCIE speeds are set so low, and how I may be able to remedy that, I'd be really grateful. 

 

My own assumption is that the chipset is limited and my board is just crammed with hardware.. So much so that the lanes have been maxed out.

 

Thanks! 

 

 

Motherboard: Asus Z270-AR

CPU: Intel i7-7700K

M.2_1 (x4 capable): Samsung 970 Evo Plus (running @2x speed)

Sata Port 1: Unoccupied

Sata Ports 2-8: Occupied

 

PCIEx16_1 Gigabyte Aorus GTX 1080Ti ( set @4x Native)

PCIEx16_2 Gigabyte Aorus GTX 1080Ti (set @8x Native)

[NumLock21]

Where are you seeing the x4 and x8 from?

[i_build_nanosuits]

dude your M.2 drive is using 4 lanes and your CPU is only 16 lanes...how could you be having 8x/8x then?

 

[NumLock21]

1 minute ago, i_build_nanosuits said:

dude your M.2 drive is using 4 lanes and your CPU is only 16 lanes...how could you be having 8x/8x then?

 

It runs from the chipset

[Mathieu9836]

7 minutes ago, NumLock21 said:

It runs from the chipset

You can't run an NVMe Drive from the chipset on PCIe Lanes, It's either connected to the CPU via 2x PCIe or Chipset via SATA and disabling SATA_1 on this particular motherboard. So basically as @i_build_nanosuits said, you are using 4 of your 16 PCIe lanes to run your 970 evo plus drive, you are left with 12 lanes which you split between the two GPUs.

[NumLock21]

15 minutes ago, Mathieu9836 said:

You can't run an NVMe Drive from the chipset on PCIe Lanes, It's either connected to the CPU via 2x PCIe or Chipset via SATA and disabling SATA_1 on this particular motherboard. So basically as @i_build_nanosuits said, you are using 4 of your 16 PCIe lanes to run your 970 evo plus drive, you are left with 12 lanes which you split between the two GPUs.

M.2 runs from the chipset not the CPU.

[badreg]

24 minutes ago, Mathieu9836 said:

You can't run an NVMe Drive from the chipset on PCIe Lanes, It's either connected to the CPU via 2x PCIe or Chipset via SATA and disabling SATA_1 on this particular motherboard. So basically as @i_build_nanosuits said, you are using 4 of your 16 PCIe lanes to run your 970 evo plus drive, you are left with 12 lanes which you split between the two GPUs.

@NumLock21 is correct. AFAIK, there are no mainstream Intel boards that have an M.2 slot wired directly to the CPU. They all go through the chipset and DMI. The only way that you can use CPU lanes for storage is to use a M.2 PCIe expansion slot.

 

Here is the block diagram for Z270. Only the three x16 PCIe slots slots are wired directly to the CPU. Everything else goes through the chipset.

 

[NumLock21]

5 minutes ago, badreg said:

@NumLock21 is correct. AFAIK, there are no mainstream Intel boards that have an M.2 slot wired directly to the CPU. They all go through the chipset and DMI. The only way that you can use CPU lanes for storage is to use a M.2 PCIe expansion slot.

 

Here is the block diagram for Z270. Only the three x16 PCIe slots slots are wired directly to the CPU. Everything else goes through the chipset.

 

 

Spoiler

 

 

I bet a lot will start complaining that their SLI setup will stop working, when they install a M.2 drive. Asus won't be that stupid.
Nvidia SLI only works in x16/x16 or x8/x8. It will not work in x4 mode no matter what you do with it. I don't think, SLI can even be enabled when the card is only running at x4 mode.
Yes the chipset has 24 PCIe lanes.

 

This is OP's board.
CPU PCIe lanes is wired to the first 2 PCIe x16 slot. So single at x16, dual at x8/x8. Everything else runs of the Z270 chipset where it provides and additional 24 PCIe lanes.

One possible reason OP is seeing x4 is due to that card being idle. Firing up GPU-Z and running the built in stress test, it should go back up to x8.

 

 

[TRITIUMNITR0X]

@NumLock21, thanks for providing a potential solution! When I have a minute, I'll check GPU-Z for expanded information and I'll be sure to tag you.

 

And to all who have responded, thanks for helping me out thus far. 

[TRITIUMNITR0X]

@NumLock21

 

Here's a screenshot of all the information you'll probably need.The cards are both under Furmark's GPU Stress Test.

 

The cards are in SLI. As well, they are not overclocked, but the thermal limit is maxed.

The card you're looking at is running in 4x Native, and the other card which isn't shown is running at 8x Native.

 

[NumLock21]

1 minute ago, TRITIUMNITR0X said:

@NumLock21

 

Here's a screenshot of all the information you'll probably need.The cards are both under Furmark's GPU Stress Test.

 

The cards are in SLI. As well, they are not overclocked, but the thermal limit is maxed.

The card you're looking at is running in 4x Native, and the other card which isn't shown is running at 8x Native.

 

Run the gpu stress tester that's built in GPU-Z