z270 + 970 EVO = DMI or Direct Cpu Lanes?

[MyLittleFella]

Hello everyone. I'm thinking about getting a 970 EVO on this next black friday sales, but something just hitted me: My 7700k supports 16 pcie lanes. All of them are in use for the GPU, since I only use SATA devices. When I Install the m2 nvme device, is it going to use the chipset lanes + dmi or the GPU will be limited to 8 lanes and the rest free for other devices? (Such as the SSD)

 

I was looking for some info online and I came across this asus video on YT:
According to it, both of the z270 drives are running though the DMI. But is that the same for a StandAlone nvme device?

 

Thanks y'all

 

EDIT: My motherboard is an Asus z270 TUF Mark 2

[Mr Technician]

Your GPU will still run on 16 CPU lanes and the 970 EVO will run on chipset lanes.

[hconverse02]

Even if your gpu uses 8 lanes, but that's fine and it won't impact gaming performance https://www.gamersnexus.net/guides/2488-pci-e-3-x8-vs-x16-performance-impact-on-gpus

[MyLittleFella]

2 minutes ago, hconverse02 said:

Even if your gpu uses 8 lanes, but that's fine and it won't impact gaming performance https://www.gamersnexus.net/guides/2488-pci-e-3-x8-vs-x16-performance-impact-on-gpus

I know, that's why I'm asking if it's possible to use 8 lanes for the gpu, 4 lanes for the SSD and 4 free lanes, but accordingly to @ThatFlashCat, it is not.

[Mr Technician]

Just now, MyLittleFella said:

I know, that's why I'm asking if it's possible to use 8 lanes for the gpu, 4 lanes for the SSD and 4 free lanes, but accordingly to @ThatFlashCat, it is not.

Oh, I misread your question then. I'm pretty sure either way is possible since you can configure PCIe lanes in bios.

[MyLittleFella]

4 minutes ago, ThatFlashCat said:

Oh, I misread your question then. I'm pretty sure either way is possible since you can configure PCIe lanes in bios.

Yeah well... I guess I'm gonna find out when I get the SSD. I don't really have an option to manage the PCIe lanes in bios. I already went through all of the options. I can set the speed of them (Gen1, 2 or 3) but not the amount of lanes.

[MyLittleFella]

Here, some screenshots from the BIOS:

[MyLittleFella]

1 minute ago, VegetableStu said:

I don't remember Z270/Z370/Z390 having more than x16 lanes from the CPU (not counting the x4 to DMI)

your motherboard's manual doesn't specify if populating m.2 slots affects lane bandwidth of the main PCIe sockets, so it's probably safe to assume both goes to DMI

 

(AMD's X370/X470 has the x4 extra from CPU for a single m.2 stick or something else)

Yeah, that's probably more like it. I mean, if it didn't go to DMI, I guess ASUS wouldn't release those high-end z270 mobos with DIMM.2 cards:

[Dedayog]

This is really interesting, and sorry to hijack a little, but what is the benefit of CPU or chipset for the NVMe drive?  Looking at 970 EVO as well if they keep dropping.

[MyLittleFella]

1 minute ago, jstudrawa said:

This is really interesting, and sorry to hijack a little, but what is the benefit of CPU or chipset for the NVMe drive?  Looking at 970 EVO as well if they keep dropping.

DMI both on z270, z370 or even z390 can bottleneck the performance of NVMe drives. Using the direct CPU lanes is better for perfomance, since the SSD will communicate directly with the CPU, which is the case of DIMM.2, as I showed above.

[Dedayog]

Just now, MyLittleFella said:

DMI both on z270, z370 or even z390 can bottleneck the performance of NVMe drives. Using the direct CPU lanes is better for perfomance, since the SSD will communicate directly with the CPU, which is the case of DIMM.2, as I showed above.

Ahh okay ,thanks.  So if I get a 970 EVO and plug it directly into the M.2 slot on my Gaming 5... I'll be fine I assume.

[Mr Technician]

1 minute ago, jstudrawa said:

Ahh okay ,thanks.  So if I get a 970 EVO and plug it directly into the M.2 slot on my Gaming 5... I'll be fine I assume.

Absolutely fine.

[MyLittleFella]

Just now, jstudrawa said:

Ahh okay ,thanks.  So if I get a 970 EVO and plug it directly into the M.2 slot on my Gaming 5... I'll be fine I assume.

 You will, which leads both of us to the question of this thread: Those m2 ports, are going to use CPU Lanes or Chipset DMI Lanes?

[Jurrunio]

3 minutes ago, MyLittleFella said:

 You will, which leads both of us to the question of this thread: Those m2 ports, are going to use CPU Lanes or Chipset DMI Lanes?

After you got the drive running, download GPU-Z and check the PCIe bandwidth the graphics card's getting. Do press the button to give the GPU some work. If it says 16x, then the SSD must be running on DMI

[MyLittleFella]

7 minutes ago, Jurrunio said:

After you got the drive running, download GPU-Z and check the PCIe bandwidth the graphics card's getting. Do press the button to give the GPU some work. If it says 16x, then the SSD must be running on DMI

Thanks!

[MyLittleFella]

1 minute ago, VegetableStu said:

I edited my earlier reply. Z370 and Z390 has the extra x4, but check the spec pages very carefully to confirm if they're being used

can't speak for every Z270 DIMM.2 boards out there, but the APEX one goes straight to DMI, lol

https://dlcdnets.asus.com/pub/ASUS/mb/LGA1151/MAXIMUS_IX_APEX/E12404_MAXIMUS_IX_APEX_UM_V2_WEB.pdf

Well, if even the APEX goes straight to DMI, I won't even bother to find out about the TUF Series, since it's cheaper than APEX. But nevermind... I still don't know if I am actually getting the device. I started this thread because I was curious.