Looking at upgrade, advice is welcomed.

[guruabyss]

I've been looking at the ASUS ROG Strix Z790-E Gaming WiFi 6E LGA 1700 and one of the things that I've been looking for is a PCIe 5.0 X4 M.2 slot with a little future proofing. The mobo also has a PCIe 5.0 X16 slot which is great for when the next gen of GPUs come out with PCIe 5.0 support. My only issue as after researching it seems the PCIe 5.0 X16 gets downgraded to PCIe 5.0 X8 if you have a M.2 in the PCIe 5.0 X4 slot. That's a bummer... does anyone know if the

ROG MAXIMUS Z790 HERO
ROG MAXIMUS Z790 DARK HERO (Can't tell if this is a new board/ refresh of the Z790 HERO??)
ROG MAXIMUS Z790 EXTREME

suffers from the same downgrade when using the PCIe 5.0 X4 M.2 slot?

[Nate152]

Hello guruabyss,

Pretty much all Z690/Z790 motherboards suffer from the downgrade when using Pcie 5.0 devices.

While it may sound like a downgrade, PCIE 5.0 x8 has the same bandwidth as PCIE 4.0 x16 at 32GB/s.

According to the conclusion in TechPowerup's article, it will be a while before you need more bandwidth.

NVIDIA GeForce RTX 4090 PCI-Express Scaling - Conclusion | TechPowerUp

[guruabyss]

@Nate152 Thank you for the quick reply! When I build computers I like to make sure over all they last 10+ years with maybe a GPU/ mem upgrades to the Mobos max over time. With the 'Raptor Lake Refresh' i9-14900K and 14900KS that might be released in Oct I want to make sure whatever mobo I pick has the best overall future proofing.

Would the ROG MAXIMUS Z790 DARK HERO be better over the ROG Strix Z790-E?

[JohnAb]

Just to throw in my opinion, I've been delighted with my 690 Hero, so I imagine the 790 Hero would be just as good. If you want the best overclocking potential for your RAM then go for a board with 2 RAM slots like the 790 Apex. More expensive, but an excellent board. Not heard a bad thing about it, apart from the earlier revisions (and that might have been the 690 versions). Any Apex made in the last 12 months will be an excellent choice. However, I would say don't buy a new board just yet though, new models for 14th Gen should be on the market very soon, as announced last month There was a recent press release from Asus about soon to launch motherboards, so have a look for that info if it interests you... 

Just remember that whatever you choose, it will be out of date in 18 months. I bought my setup back in April last year, pretty much all top of the range. Look at my spec now (below) and you'll see that things have moved on considerably. Still works great though, fast and stable, so I'm still very happy. 

[ExcessiveGBH]

Looks like the 14900KS will have 20 CPU lanes, wonder if that will help not down grading bandwidth in occupied M.2 slots & GPU. 

[Nate152]

Hello ExcessiveGBH

12th, 13th and 14th Gen cpu's have 20 pcie 4.0 lanes or 16 pcie 5.0 lanes.

As long as you stick with pcie 4.0 devices, you can use the M.2_1 slot and still have your gpu run at x16.

The other M.2 slots run off the chipset lanes.

[ExcessiveGBH]

Thanks for the info, should've looked at the 13th gen specs.

Looks like no HEDT for Intel (Rampage 7), probably go with the ROG Maximus Z790 Dark Hero.

Do you know if in the BIOS you could set the Pcie Gen 5 slot for NVM hard drive to Pcie Gen 4 if you have a Gen 5 hard drive?

[Nate152]

Yes, you can set the M.2_1 slot to Gen 4 with a pcie 5.0 ssd.

[ExcessiveGBH]

Hi Nate152

Came across this video about PCIe Resource allocations.  https://youtu.be/av7iKQfFtaQ?si=o8oxpmDtaKCiiVo-

He mentions something about 4 CPU lanes not being reallocated???

So now I'm just wondering if I have the five M.2 slots populated as Gen 4 and a GPU 4090 (I know that 3 of the M.2 slots are through the chip set) dose my GPU become x8 or stay at x16?

[bobvoeh]

13900k/ks also has 20 CPU Lanes.