X299 EVGA Dark PCI-E lanes question.

[TheNaitsyrk]

I have a question regarding M.2 and SLI on the X299 Dark.

 

My question is as follows: I will be using SLI, and I'd like to run it at 16x and 16x speeds so I'll use slot 1 and 4 on the motherboard. That is clear to me.

 

If I use M.2 devices like 2x NVMe SSDs, I should also be fine and GPUs should retain their 16x and 16x speeds (please correct me if I'm wrong).

 

Now, if I plug anything into the slot 6, it will mean that one M.2 will not work? https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.evga.com/support/manuals/files/151-SX-E299.pdf&ved=2ahUKEwis_8qSo8LlAhVgTRUIHZ0lDaYQFjAAegQIAxAB&usg=AOvVaw1ZmZo01TYTTzShWtnp_5-D

 

What I want to do, is I want to add a card with some USB 3.0 ports so I can use my Pimax 4K, but I don't want to lose cards in 16x and 16x and I don't want to lose any M.2 slots.

 

Or, should I run cards at 8x each and essentially have all the bandwidth in the world left.

 

Any help is appreciated.

Thank you.

[For Science!]

11 minutes ago, TheNaitsyrk said:

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They will work, if you don't have enough CPU lanes, it will draw them from the PCH

[TheNaitsyrk]

10 minutes ago, For Science! said:

They will work, if you don't have enough CPU lanes, it will draw them from the PCH

The explanation in EVGA manuals are somewhat hard to understand hence why I had to ask.

 

So I know that PCIe 1 shares bandwidth PCIe 2.

PCIe 4 shares it with PCIe 3. So top 4 ones are out of use because of the GPUs.

 

If I use M.2 NVMe 2x. PCIe 6 is unusable.

However 4x is not linked to anything so I can still add whatever there.

 

Do I understand it right?

 

Like I'll be able to add absolutely nothing to the rig PCIe wise if I follow with this?

[For Science!]

2 minutes ago, TheNaitsyrk said:

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We are talking about a 44 lane cpu right? (79xx)

[TheNaitsyrk]

Just now, For Science! said:

We are talking about a 44 lane cpu right? (79xx)

48. 10980XE not released yet.

[NumLock21]

Did you get that board yet?

[TheNaitsyrk]

1 minute ago, NumLock21 said:

Did you get that board yet?

I have it yeah.

[DildorTheDecent]

22 minutes ago, TheNaitsyrk said:

If I use M.2 devices like 2x NVMe SSDs, I should also be fine and GPUs should retain their 16x and 16x speeds (please correct me if I'm wrong).

It should be fine. Storage devices generally run through the PCH.

22 minutes ago, TheNaitsyrk said:

Now, if I plug anything into the slot 6, it will mean that one M.2 will not work? https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.evga.com/support/manuals/files/151-SX-E299.pdf&ved=2ahUKEwis_8qSo8LlAhVgTRUIHZ0lDaYQFjAAegQIAxAB&usg=AOvVaw1ZmZo01TYTTzShWtnp_5-D

That's usually what happens. The PCIe 4x slots and M.2 slots share bandwidth. Seems to be an amount of flexibility with that bottom slot though.

 

There's a table on the big PCB that the board ships with:

(There's two "Hi-end 3SLI" options. The top one should be 2SLI)

 

PE6 pulls from the PCH whenever both PE1 and PE4 are in 16x mode. PE6 might be able to pull from the CPU whenever either slot (PE1 and PE4) is reduced to 8x. I think, not sure.

[For Science!]

Just now, TheNaitsyrk said:

48. 10980XE not released yet.

Well, since I cannot guess through my crystal ball about future products, I will just say about the current 44 lane CPU.

 

Slot 1: GPU 1 = (16 lanes from CPU)

Slot 4: GPU 2 = (16 lanes from CPU), cumulative 32 lanes used

M.2 (110 mm): PCIe NVMe 4x = (4 lanes from CPU) *Disables U.2 slot, 36 lanes cumulative

M.2 (80 mm): PCIe NVMe 4x = (4 lanes from CPU), 40 lanes cumulative

 

Under these conditions, if you put a non-video card into slot 6, this receives 4 lanes from the PCH (Chipset).

 

How the additional 4 lanes for the 10th gen get distributed is anyones guess

 

[TheNaitsyrk]

4 minutes ago, For Science! said:

Well, since I cannot guess through my crystal ball about future products, I will just say about the current 44 lane CPU.

 

Slot 1: GPU 1 = (16 lanes from CPU)

Slot 4: GPU 2 = (16 lanes from CPU), cumulative 32 lanes used

M.2 (110 mm): PCIe NVMe 4x = (4 lanes from CPU) *Disables U.2 slot, 36 lanes cumulative

M.2 (80 mm): PCIe NVMe 4x = (4 lanes from CPU), 40 lanes cumulative

 

Under these conditions, if you put a non-video card into slot 6, this receives 4 lanes from the PCH (Chipset).

 

How the additional 4 lanes for the 10th gen get distributed is anyones guess

 

Saves my ass again. Appreciated!

 

So I could stick 10g NIC or anything in Slot 6 as long as it's not a GPU, or the 4x slot.

[NumLock21]

12 minutes ago, TheNaitsyrk said:

I have it yeah.

Based on the manual as what you've mentioned, your GPUs will go to slot 1 and 4, but after that, the only slot available to you is slot #6. Slot #6 uses lanes from both CPU and PCH, depending on configuration. Not sure what EVGA means by that, maybe there is something in the bios that lets you select what lanes you want to use.

 

 

[TheNaitsyrk]

2 minutes ago, NumLock21 said:

Based on the manual as what you've mentioned, your GPUs will go to slot 1 and 4, but after that, the only slot available to you is slot #6. Slot #6 uses lanes from both CPU and PCH, depending on configuration. Not sure what EVGA means by that, maybe there is something in the bios that lets you select what lanes you want to use.

 

Yeah, if I can add one more card I'll be okay with it. And it seems that I can. 10GB NIC for instance.

 

I'll buy USB C hub for more usb 3.0 ports.

[NumLock21]

Just now, TheNaitsyrk said:

Yeah, if I can add one more card I'll be okay with it. And it seems that I can. 10GB NIC for instance.

I took a careful look at the manual again and slot 3 can be used too. So that means the card can be sandwich in between the 2080TIs or in slot #6.

[TahoeDust]

Congrats on the board.  It is awesome.  I am probably going to be putting mine back into use when the 10-series chips are available.