PCI Express Bandwidth test only 13.13 GB/s

[M0NSK3R]

I ran the bandwidth test and it says I have a PCIe x16 3.0, and I'm only getting 13.13 GB/s.
Is this a normal result?
Thank you.

[Huperspace]

normal:
https://en.wikipedia.org/wiki/PCI_Express#History_and_revisions

[M0NSK3R]

Thanks.

[Gorgar66]

I enter this thread. I ran the test today and bandwith is at 6,42 Gb/s with a RTX 2070 Super and Pci Express 3.0 x 16.
The test runs very poorly on 7 Fps. I assume this is too less for the card, isn't it?
What can cause this result?
My Rig is on my Profile.
I have three m.2 SSD's inside the Pc. Can they cause this result?

[Gorgar66]

Ok, I removed one of my m.2 SSD's; The one's in Pcie Slot. Now my Bandwith has exactly doubled. 12,8 Gb/s.
Is this a limiting factor for the graphics card, when I put more m.2 SSD's into my Pc?

[Migz - DH]

I can't say for certain without knowing what motherboard you use or what pci-e slots you have things in. Here's a data point though: it is possible that the pci-e ssd took 8 lanes from the graphics card while it is installed. I think that you should read your motherboard's documentation about its pci-e slots and how the lanes are configured.

[UL_Jarnis]

Originally posted by Gorgar66:

Ok, I removed one of my m.2 SSD's; The one's in Pcie Slot. Now my Bandwith has exactly doubled. 12,8 Gb/s.
Is this a limiting factor for the graphics card, when I put more m.2 SSD's into my Pc?

Depends on your configuration. Sounds to me like your M.2 drive is "stealing" PCIE lanes from GPU, but would need to know about the hardware config to be sure.

[Gorgar66]

@UL_Jarnisa: Hardware config is on my Steam Profile page.
I have three m.2 SSD's inside. Two on the mainboard slots and one in a Pcie Slot.

[UL_Jarnis]

Mainboard: Gigabyte Z370 Aorus Gaming 7

So it has three PCIE 16x slots

1st and 2nd are CPU connected. If you put anything to 2nd slot, it will steal half the lanes from the first slot.

Move the PCIE connected M.2 to the third slot that comes from chipset (which has 24 lanes to share around, 6 of which are used for USB and LAN, so 18 left over - enough for 3x M.2 at 4x each. But chipset has no connection to first two PCIE 16x slots, those are linked to CPU only, which only has 16x lanes to go. so either 16x + 0x or 8x + 8x on first two slots.

But this also can complicate on what motherboard M.2 slots are used.

See this:

http://www.overclock.net/content/type/61/id/3145027/width/500/height/1000/flags/LL

On a more general level: As soon as you go past one GPU and one m.2 drive on a "consumer" setup you should research things carefully as to how exactly PCIE lanes are handled on your specific board. If you need a lot of PCIE lanes, consumer chipsets can become a limitation. There is a reason why Threadrippers and X299 Intels exist and it is mainly about the IO bandwidth.

[Migz - DH]

1 x PCI Express x16 slot, running at x16 (PCIEX16)
* For optimum performance, if only one PCI Express graphics card is to be installed, be sure to install it in the PCIEX16 slot.
1 x PCI Express x16 slot, running at x8 (PCIEX8)
* The PCIEX8 slot shares bandwidth with the PCIEX16 slot. When the PCIEX8 slot is populated, the PCIEX16 slot operates at up to x8 mode.
1 x PCI Express x16 slot, running at x4 (PCIEX4)
* The PCIEX4 slot shares bandwidth with the M2P_32G connector. The PCIEX4 slot operates at up to x2 mode when a PCIe SSD is installed in the M2P_32G connector.
3 x PCI Express x1 slots
* The PCIEX1_3 slot shares bandwidth with the SATA3 1 connector. The SATA3 1 connector becomes unavailable when the PCIEX1_3 is populated.

If the 3rd M.2 is in the 2nd pci-e slot, yes, it's taking 8 lanes away from the GPU.

[Gorgar66]

@UL_Jarnis and Migz-DH. Thank you very much!

[Gorgar66]

Just to explain. The m.2 slot us directly under the graphics card and gets no air. I putted the m.2 in this slot and now I have full bandtwith. I hope that the cooler from Gigabyte works ok.
Thanks again.