Question M.2 Layout + Dim.2

[oakes88]

So i have preordered the new Z590 Rog Maximus 13 Extreme Glacial and I'm looking at its 5 M.2 ports. Now for context, I'm upgrading from Z97 so I predate m.2s. I know some use the CPU PCI lanes and some use the PCH/Chipset. Now I've looked at the digital manual and can't understand it, Please can someone help me figure out which of the 5 dims use each the CPU and the PCH/Chipset. As i want to populate as many m.2 bays as possible without affecting the GPU which will be 3080/3090 "stock depending"

Also which type of M.2 to use I.E nvme /SATA. I was thinking of thee WD SN850 2TB for boot and a few games, but then if the other slots won't run at full speed then ill get cheaper m.2s if it makes more sense. Pl,ease help i have been googling for over 3 days trying to learn what i can

Thanks in Advance: Andy

ROG Maximus XIII Extreme Glacial

10th-gen Intel® Core™ desktop processors EATX motherboard with Aura Sync, SupremeFX, ROG Audio, Dual M.2, Realtek LAN, Wifi , M.2 heatsink and USB 3.2 Gen 2

rog.asus.com

https://rog.asus.com/motherboards/rog-maximus/rog-maximus-xiii-extreme-glacial-model/helpdesk_manual

 

[rgd1101]

none of the use bandwidth for the gpu

 

[oakes88]

Doesnt a few of them work off the pci lanes built into the CPU, same as the gpu ?

 

[rgd1101]

yup. page xiv on the manual

 

[oakes88]

on page 14 i see in the chart M.2_1/_2 both state CPU attached surly that means it dose not use the PCH and uses the CPU.

I dont see anywhere saying Dim.2_1 either

The only part that is clear is that Dim.2_2 meaing the 2nd slot on it is sata related which is fine but then does that mean dim.2_1 uses the cpu lanes?

 

[geofelt]

M.2 devices are very nice from the connection point of view.
No power or data cables required.
The advantage of pcie connection is faster sequential benchmark speeds.
And the use of pcie 4.0 is twice again faster.
Some 10x better than sata.
But, this is not as good as it sounds. Videos are showing minimal differences between using sata or pcie for such things as game loading times. Less than 1 second out of 25 for example.
The difference is huge compared to a HDD.
Most of what we do is random and the performance differences between sata and pcie are minimal.
On some motherboards with the Z590 chipset, there are notes that the first m.2 pcie slot will be disabled unless a 11th gen processor is installed.
Best to check that out on your motherboard.

I see very little benefit from using many m.2 devices compared to a single large device.
You can buy a ssd in 4 or 8tb sizes, even up to 15tb.
For bulk storage, I would not worry much about m.2 or 2.5" formats.

I would not go cheap on a ssd. They hold your sensitive things.
I would stick with brands that are not parts assemblers and go with intel or samsung.
They make their own controllers and nand chips making them better able to integrate parts

 

[rgd1101]

on page 14 i see in the chart M.2_1/_2 both state CPU attached surly that means it dose not use the PCH and uses the CPU.

I dont see anywhere saying Dim.2_1 either

The only part that is clear is that Dim.2_2 meaing the 2nd slot on it is sata related which is fine but then does that mean dim.2_1 uses the cpu lanes?

those that not in the A,B,C are unique. they are not shared

 

[hotaru.hino]

If you're worried about graphics card performance drops due to fewer PCIe lanes being assigned to it, the RTX 3080 doesn't even drop below 95% on average if running on the equivalent of PCIe 3.0 x8. And if you use a Rocket Lake CPU which has PCIe 4.0 lanes, then the performance difference is within a margin of error.

At worst assuming you're not populating any other x16 PCIe slot, the GPU is getting 8 lanes.

 

[oakes88]

Im planning on 11900K which is preordered same goes for the Glacial board. yeah, I understand that it's gen 4 and has like 20 lanes. I know that the 3080/3090 doesn't max out the 4.0 bandwidth at 8/16X.

i also understand that having a lot of them isn't really necessary, I just want to populate the board with as many as possible so i don't have to mess around with data cables and that. Going for an ultra-clean build.

The nvme drives I've seen I.E the WD SN850 only go to 2TB which is fine but I would get like 3 of them. ideally one for boot and the other for games and such. i understand that there may not much really world difference between Sata SSD's and nvme may be tiny but there will be point that the 4GB read-write comes in hand compared to 550MB surely that's the case. For the build, money is too much of an issue so if its actually better and the board can use all nvme at llike 4gbs then id prefer to go that route Like i said earlier I'm just not sure which slots run off CPU and which use the PCH and if the pch ones will be able to take advantage of the 4gb speeds as it is sata.

Ive tried looking at the Manual on the support page but tbh i dont understand it. ther than one part where it says the top pcie 4.0 X1 slot will be disabled which is fine as i will only be using 1GPU

 

[oakes88]

On Page 14 of the Manual am i reading it right that if i use a GPU in PCIEX16_1 then i cant use a m.2 in either M.2_1/2 and have the GPU at 16X and the m.2 in 4X ?

 

[geofelt]

On Page 14 of the Manual am i reading it right that if i use a GPU in PCIEX16_1 then i cant use a m.2 in either M.2_1/2 and have the GPU at 16X and the m.2 in 4X ?

Sounds complicated.
I think much depends on if you will be using graphics cards with pcie 4.0 capability along side m.2 pcie 4.0 devices
That potential doubling of load when both are fully active will probably limit you to two such devices.
I don't see that as a big issue this generation of devices. Graphics cards are hardly limited by pcie 3 or even 2.
You may be interested in the practical experience of the difference between HDD, sata, pcie3 and pcie4.

Storage Game Loading Test: PCIe 4.0 SSD vs. PCIe 3.0 vs. SATA vs. HDD

What sort of storage do you need to play today's games and provide the best loading times? Do you need a PCIe drive? Do you need something...

www.techspot.com

Remember that normal usage is one thing at a time(QD1)
Synthetic benchmarks used for marketing use quque depths much higher, like QD32 which is unrealistic on a desktop pc.

I can understand the attraction of all m.2 storage and I would agree.
For a price, today you can get an 8tb device(pcie gen 3 only)
https://www.newegg.com/corsair-8tb-mp400/p/N82E16820236688

Since these devices are getting better and cheaper by the day, I think I would start with the single gen4 2tb device and add whatever is good later when it fills up.

 

[oakes88]

Yeah it is getting complicated, i just want to know which m.2s on the MOBO run off CPU and PCH LOL

I would like to keep it as standard as possible meaning running the GPU at 4.0 X16 and a gen 4 NVME at X4

The rest "however many that is" can use PCH ill decide on capacity later


Yeah, 2tb to start with would be nice but would like one extra as i do have a decent-sized steam library haha, also when the build is done adding an M.2 to that board with a full loop isn't going to be easy to do. So I want to populate what i can from the beginning

 

[hotaru.hino]

Yeah it is getting complicated, i just want to know which m.2s on the MOBO run off CPU and PCH LOL

I would like to keep it as standard as possible meaning running the GPU at 4.0 X16 and a gen 4 NVME at X4

The rest "however many that is" can use PCH ill decide on capacity later

The M.2 slots are coming from the CPU. You can only populate one if you really want to keep it at x16 for the GPU and x4 for the SSD.

 

[oakes88]

But some of them have to be used by the PCH or there would be no point putting 5 on a board

 

[rgd1101]

cpu can have 1 m.2 the rest is from the pch

 

[geofelt]

You may be overthinking all of this.
The slots are there, and they can all be used if you have 11th gen processor.
If you can manage to run all devices at the same time, I imagine that they will all do ok.

 

[hotaru.hino]

But some of them have to be used by the PCH or there would be no point putting 5 on a board

Here's what you can do then. Buy two NVME drives, build the system like normal, and use GPU-z to figure out how many lanes the GPU received. Whatever drops the lane count to 8 are the ones that you don't populate.

 

[oakes88]

Here's what you can do then. Buy two NVME drives, build the system like normal, and use GPU-z to figure out how many lanes the GPU received. Whatever drops the lane count to 8 are the ones that you don't populate.

May actually do that tbh lol

 

[geofelt]

4 lanes are sufficient to run a pcie4.0 ssd at max.
You are worried about nothing important.