ROG MAXIMUS Z790 DARK HERO & 14900K Speed M2 5.0 Socket

[CHewBaKa]

Hello, I want the board ASUS Rog MAXIMUS Z790 DARK HERO
and get the 14900K. My question is . I think I read that the 5.0M2 space cannot deliver full performance. In the specifications it says under Storage: M.2_1 slot (Key M), type 2242/2260/2280/22110 (supports PCIe 5.0 x4 mode.)* *
Below is the explanation for**: ** M.2_1 shares bandwidth with PCIEX16(G5)_2. When M.2_1 is enabled, PCIEX16(G5)_2 will be disabled and PCIEX16(G5)_1 will run x8 only.
What does that mean exactly?Will a Gen5 m2SSD in this slot not run at full performance?
I'm actually planning on doing a raid to get twice the speed. But that would only work with the Gen4 slots. There is only one Gen5.
thank you for your effort

[dubignyp]

In Gen4 M2 this will be enough for you, don't worry about Gen5 it's just marketing, you won't see any difference. I think in life, sometimes you have to forget the 2 seconds less it takes to load a game between Gen4 and Gen5. Especially since the Gen5 heats up a lot in the motherboard, so it works a lot.

The Gen4 7000 MB/s is already phenomenal in which we often do not reach the end of 7000 in speed, only 4000 is already enormous.

Unless you are a server with multiple graphics cards, multiple hard drives with multi-video tasks, the Gen5 is completely useless to you.
I have the motherboard that you inform me of, I placed Gen4 and it is already way too ultra fast.

[GTX680SLI]

"will run x8 only." This is true, however, don't let anyone tell you what "you" need. Asus was misleading, even the manual and support tickets claimed there wasn't a x8 drop and you'd have x16.  My extreme came brand new and looked like someone threw it down a hallway. I regret my purchase. 😞

[CHewBaKa]

Hello
GTX680SLI,
Thank you for your honest answer. It's not about the money for me. I care about the truth. What should I do with an M2. 5.0 socket which is also connected directly to the CPU, but does not provide full performance. The previous speaker says that I will never need it. I don't even know, but he thinks he knows. When the so-called “Revodrives” appeared as the first fast alternative after the HDDS, there was no clear answer from Asus as to whether they would work on my board or not. OCZ also kept a low profile and was sure it had to work somehow. So I bought it and experimented and reinstalled Windows XP again and again on this OCZ RevoDrive 240GB SSD until it finally ran reliably. I was rewarded with data rates of an average of 600MB/s and around €800 less on my account. Even back then, the prices of the things were beyond good and bad.
That's it for this little digression into my past, what I remembered about this discussion, thank you for that.
In the meantime I have been able to talk to my contact at Aus and the answer is clearly in the specifications of PCI-E 5.0. Here is a small table for clarity.

If we read the table correctly, we have x4 with a data throughput of 16 Gb/s, x8 32GB/s and finally x16 with 64GB/s. To draw a conclusion from this we need the following information:
With PCI Express 5.0, the maximum read and write speeds double again. Theoretically, up to 16 GB/s is possible. With PCI Express 4.0 it was up to 8 GB/s on 4 lanes. The fastest NVMe SSDs reached around 7,000 MB/s read and 5,000 MB/s write, so maximum speeds of around 14,000 MB/s read and 10,000 MB/s write are realistic for flash drives with PCIe 5.0.
This results in the following answer to my question, which I then finally answer myself.
If I want a PCI-E5.0 SSD on this board as a single solution for my OS (W11), a speed of up to 14000MB/S (equivalent to 14GB/S) is possible on the M2.5.0 socket.(with the right 5.0 SSD)
That would be one option to install the W11, or I could generate a raid on the remaining 4M2.4.0 sockets. What data rates this will bring remains to be seen, but if I have calculated correctly up to 28GB/s. The 4.0 socket only allows up to 16/GBs. If I have interpreted the table correctly.

So my friend GTX680SLI, if I understood you correctly, did your brand new board arrive used? Where did you order this, I didn't understand that clearly? But that's not possible. Couldn't you have sent it back? In any case, this is very annoying. I often spend hours complaining about deliveries, regardless of whether something is missing, used or the package simply disappears before it arrives. If companies don't change to react more accommodatingly when there are problems with delivery, then at some point you will wonder where your customers have gone! If there are any delivery discrepancies, my employees are instructed to fill out a form and send it to me. I then decide whether and when we should separate from this supplier or seller.

So my dear GTX680SLI,
I wish you and your family a nice Christmas time, stay healthy and cheerful everyone. Don't let yourself be annoyed, life is far too short. Thank you for your inspiration to Me.
With best wishes I remain!
Flighty

[Jiaszzz_ROG]

Hello, @CHewBaKa 

According to the specification inquiry, please refer to the ROG MAXIMUS Z790 DARK HERO user manual, page XV:

The notation indicates that the M.2_1 slot shares bandwidth with PCIEX16(G5)_1 and PCIEX16(G5)_2.
And when M2_1 is occupied, the bandwidth of both PCIEX16 (G5) is constrained.

Thank you.

[dubignyp]

For this you have to put the M2 in slot 3, if you only have one.

[CHewBaKa]

Hello and thank you for your interest in this discussion. If only a 4.0 SSD is used, you are right.

All the best... Merry Christmas!

[CHewBaKa]

Thank you for your effort, I have already read the manual. Unfortunately, it does not fully explain what happens when sharing in terms of speed. The use of an SLI network is also not discussed. From a purely theoretical point of view, when using a GPU, the M2_1 slot should drop to x8 and when using 2GPU"s (SLI) to x4. The other slots of the M2 remain unaffected, as the M2.5.0 slot is connected directly to the CPU. That's why they're not mentioned in your table in the manual. I think we have to wait for the hardware test, which will be postponed from my side. Only when I've taken the measurements will it be clear which data rates will ultimately be available. It is It's still unclear which 5.0 SSD I will use for testing, many of them are out of the question. After that, I will install a raid with 2 or 3 (redundant) Samsung 990Pro SSD4.0 on the appropriate slots. I expect at least 14,000 Mb/s. I I think the results will be higher. Which will then make the use in the 5.0 slot obsolete.

Stay healthy and have a nice Christmas...

[dubignyp]

By the way, the capacity of PCIe 5 is obsolete, which means which would become PCIe 4; quite frankly we don't care a bit, because we don't see any difference between what you did in PCIe 3. I don't see any difference for a graphics card, PCIE 3, 4, 5 is more useful in processing of data on a hard disk.
Example, if you connect a Hyper M2 PCIe to add other additional M2 disks.

[Dakota1]

We lose 4 lanes to the mist with x8/na/x4.  What happened to the other four lanes?????