Question about X670E chipset PCI Lanes

[MyLittleFella]

So, I bought a ROG Crosshair Hero X670E. Great motherboard.

One thing that took my att is: PCI Lanes: If you check AMD's website for Ryzen 7700x (my new CPU) it says up to 24/28 PCI Lanes.

 

On the other hand, here they put it like 16 lanes for GPU and other 8 lanes for storage, giving the 24 lanes as said on the website.

 

But, on Asus Manual, apparently you can't use the PCI lanes for storage without taking 8 lanes from the GPU, I'm honestly confused, where are the other 8 PCI lanes?

 

 

[Shimejii]

As far as i know, its the M.2 Card they throw into these expensive boards that can hold up to 4 (sometimes 8 of em)  NVME drives which would then require 16 lanes since its 4 lanes per card, and plug into one of the PCI-E Plugs instead of the M.2 connector on the board. Im pretty sure this is a 2 drive card, so it would be 8 by itself but not completely sure.

 

Occasionally two NVME drives plugged in would cause one to be on the CPU lane, then the other on the Chipset lane and would disable SATA plugs. These new drives have slightly more PCIE lanes (use to be 20) so it would be a limit of one PCIE drive before you would lose chipset allocated lanes to SATA or other things.

[RONOTHAN##]

It's not actually that confusing, they just worded it kinda weird (I had to reread it 4 times to understand what they were trying to say).

 

There are 2 PCIe x16 slots on the motherboard. When the first one is only populated, it runs at full x16 bandwidth. When the second is populated, the first one runs at x8 and the second runs at x8. There are 4 NVMe slots directly on the motherboard, 2 are wired directly to the CPU and run at x4 PCIe Gen 5, the other two run off the chipset ant Gen 4. None of those slots share bandwidth with any of the PCIe devices

 

Where the confusion comes into play is that ASUS wanted to get another NVMe slot on the motherboard, but looks like they ran out of PCB space to do it. Instead, they bundled with the motherboard a PCIe Gen 5 adapter, so what they're referring to in that passage was that when you use that PCIe adapter card, the GPU will drop down to x8 operation like it would with any other NVMe device. If you don't plan on using that expansion card, there's nothing to worry about. 

[Dedayog]

How do you justify a motherboard more expensive than the cpu?  So much money could be deployed into actual performance gains.  

 

Would have gotten the 7900x or more ram or more storage orote pizza, etc.

 

What do you worry about pcie lanes for?   Do you have a need for all of them for production work?  Dir gaming it matters not a lick.

 

I hate to see the waste of money for expensive motherboards that don't do shit for people.

 

Can you return it?  Gigabyte's b650 for $220 compares incredibly well the even the best 670 boards for practical use.

[MyLittleFella]

8 minutes ago, Dedayog said:

How do you justify a motherboard more expensive than the cpu?  So much money could be deployed into actual performance gains.  

 

Would have gotten the 7900x or more ram or more storage orote pizza, etc.

 

What do you worry about pcie lanes for?   Do you have a need for all of them for production work?  Dir gaming it matters not a lick.

 

I hate to see the waste of money for expensive motherboards that don't do shit for people.

 

Can you return it?  Gigabyte's b650 for $220 compares incredibly well the even the best 670 boards for practical use.

Well thank God it's my money and not yours.

[Dedayog]

2 minutes ago, MyLittleFella said:

Well thank God it's my money and not yours.

Doubt god has anything to do with it but yes, it's your money and not mine.  

 

Hope the motherboard gets you what you need it to . It's a serious beast.

[Somerandomtechyboi]

1 hour ago, Dedayog said:

How do you justify a motherboard more expensive than the cpu?  So much money could be deployed into actual performance gains.  

 

Would have gotten the 7900x or more ram or more storage orote pizza, etc.

 

What do you worry about pcie lanes for?   Do you have a need for all of them for production work?  Dir gaming it matters not a lick.

 

I hate to see the waste of money for expensive motherboards that don't do shit for people.

 

Can you return it?  Gigabyte's b650 for $220 compares incredibly well the even the best 670 boards for practical use.

unlike last gens joke crosshair boards that get beaten by the proart line i/o wise this time the proart line is somehow worse than the crosshair in i/o

 

Although if you dont really need that much i/o its still pointless nontheless =p

 

The other qualities of the crosshair particularly ocing related is pointless aside from xocers but those guys would prob want a board like the z690 kingpin instead, good vrms a dime a dozen, you wont get far without direct die due to abhorrent ihs design (ihs too thicc) anyways, good ram topologies useless due to the fclk thing unless you get 8000+ working or something, etc.

[MyLittleFella]

.

[RONOTHAN##]

4 minutes ago, MyLittleFella said:

Hey bro I appreciate your answer. So if I got this right, this is how it works: There are 24 lanes total. 16 of those are hooked to the 2 PCIe Slots, and the other 8 are divided into 4 for a m2 connection each. 

 

The m2 card would be for a third m2 PCIe 5.0 storage device.

The other 2 motherboard m2 slots are gen4 and are connected through the chipset.

 

Is that right?

Yeah, that's right.