Intel 10gbe x540-T2 on Asus motherboard PCie lane limitation

[Zigourney]

Hi

I was hoping someone could help clarify for me about the limitations of my motherboards PCI express lanes as I am about to install a 10gbe Intel x540-t2 card in it but I have other components which are taking up pci lanes and I am a bit concerned that I am about to run into some issues.

I am basically upgrading my current Synology server from the DS918+ to the DS1819+ in order to advantage the 10gbe capability on the DS1819+. I have just bought a couple of Intel x540-T2 cards off ebay, one for my windows 10 PC and the other to go in the DS1819+. The cards are listed on the synology site as compatible with the NAS. The Intel x540 cards are PCIe version 2.1 X8.

My PC specs are:
Asus mATX Z370 board that has 2 x PCIe 3.0 x16 slots (x16 or dual x8) and 2 x PCIe 3.0 x1 slots.
ROG STRIX Z370-G GAMING | Motherboards | ASUS Global

CPU is intel 8th Gen Core i5 8500 The intel Ark shows this CPU as having Max number of 16 PCI Express lanes.
Intel® Core™ i5-8500 Processor (9M Cache, up to 4.10 GHz) Product Specifications
Graphics card Palit GeForce GTX 1050 Ti KalmX silent card
Sound Card Creative Labs Sound blaster X-Fi PCie x1 card

The first x16 slot in my board is populated with the pcie 3.0 GFX card.
The second is a pci express x1 slot but not being used as its being blocked by the double width gfx card.
The third slot is a pci express x16 slot currently not being used - and I intend to install the Intel x540 into that.
The fourth slot is a pci express x1 slot populated with my sound card.

Now my understanding is that if the two x16 slots are being used then they will both run at x8 speed, therefore my graphics card will run at x8 speed and the Intel x540 card will run at x8 speed, and that is fine because I don't game on my PC but I am only using the graphics card in order to run a 4k monitor to watch 4k content.

So the Intel Ark website shows my CPU only supports max of x16 PCI express lanes. So if x8 is used for the GFX card and another x8 is used for the Intel x540 that equals 16 and therefore does that mean I can no longer use my x1 sound card because I have exceeded the number of supported PCI express lanes of 16?

 

[necr]

Hey there,

your CPU has 16 lanes total (you can use 1x16x or 2x8x, as you described) and a separate DMI3 to Z370. All peripherals (PCIx1, SATAs, M2s, USBs) are connected to Z370.
Sometimes BIOS doesn't detect cards correctly, if needed, force PCIE to 2X 8x and you're good to go.

P.S Card is PCIe gen 2, so expect your graphics card to fall back to gen 2 too.

 

[Zigourney]

Hey there,

your CPU has 16 lanes total (you can use 1x16x or 2x8x, as you described) and a separate DMI3 to Z370. All peripherals (PCIx1, SATAs, M2s, USBs) are connected to Z370.
Sometimes BIOS doesn't detect cards correctly, if needed, force PCIE to 2X 8x and you're good to go.

P.S Card is PCIe gen 2, so expect your graphics card to fall back to gen 2 too.

Thanks for replying. Sounds like from what you are saying everything in the PC will all work simultaneously, but I may see the gfx card fall back to gen 2 speeds, therefore will have gfx card running at gen2 x8 and the x540 card running at gen2 x8? That's a shame, I was hoping the switching between PCI express version 3 and 2 would be independent of each other so the gfx card can run at gen3 x8 and the x540 card can run at gen2 x8.

In either case the x540 will run at its full speed, but my gfx card may be quite badly impacted? I dont play any games on the PC but do rip a lot of large 4k video files and play them back on the PC via a 4k monitor. Do you think the fall back of the gfx card to gen2 x8 will have a big impact on full bit rate 4k video playback on the PC i.e 4k 60hz HDR playback?

 

[vangoose]

I have similar boards from asus, they all act very weird. ie. I put Intel SSD750, it works, if I put P3700 which is the enterprise version of 750, it doesn't post. Pretty much any enterprise devices will make the asus boards not post.

For your question, the x4 slot is PCI-E 2.0 but it shares bandwidth with x1 slots. If you don't have devices on x1 slots, you may try to use the x4 slots to see. You will get less performance but for home use, you will hardly notice it.

 

[Terry Kennedy]

Thanks for replying. Sounds like from what you are saying everything in the PC will all work simultaneously, but I may see the gfx card fall back to gen 2 speeds, therefore will have gfx card running at gen2 x8 and the x540 card running at gen2 x8? That's a shame, I was hoping the switching between PCI express version 3 and 2 would be independent of each other so the gfx card can run at gen3 x8 and the x540 card can run at gen2 x8.

Intel X550 is the updated version of X540 and uses 4 lanes of PCIe 3.

 

[Zigourney]

Intel X550 is the updated version of X540 and uses 4 lanes of PCIe 3.

Yes I know that, but have you seen the price for two X550 cards!

Anyway I have completed the upgrade over the last weekend. I upgraded to the Synology DS1819+ and migrated my disks (four 10TB Seagate Barracuda Pros) and installed the Intel X540-T2 card in the DS1819+.

I also installed a X540-T2 into the second x16 slot of my PC motherboard (the first x16 slot has my GFX card in it), and I have my soundcard in the last PCie x1 slot. I also have a couple of Samsung SATA3 SSDs, the first one is a Samsung 860Evo 1TB for my OS Windows 10 pro boot drive, the second ssd is also a Samsung 850 Evo 500gb just for fast file storage. I checked the bios and it was showing both the x16 slots running at x8 (which was expected) and I could assign the first x16 slot at x8 Gen3 and the second x16 slot at x8 Gen2 independently in bios.

I then played back some 4k 60hz hdr files on my PC and used CPU-Z and GPU-Z to show me the PCIe link speed and it showed my GFX card running at PCIe x8 v.3.0 - this is good news which means the two x16 slots in my motherboard can run independently of each other, i.e. the first slot with my GFX card is running at x8 Gen3 speeds. I did not see or feel any performance impact on GFX card running at x8 speeds.

Next I direct connected both the intel X540 cards PC<-->Synology DS1819+ via a 1meter cat6 cable, and did some transfer speed testing using 4k mkv file (size 70Gigs). I was hitting 450MB/s both ways. I then proceeded with changing the MTU to 9000 on both NICs and the transfer rate increased to 475MB/s. I ran the tests several times in both direction, changing the file name each time before running the transfer in order to rule out windows using a cached file from the previous test and the speed was rock solid bouncing up and down from 475-500MB/s in both direction. I also manually timed the file transfers and calculated the transfer rate, and the effective overall transfer rate was 475MB/s consistently.

I am very happy with the speeds, I have gone from a transfer rate of 113MB/s (1 gigabit) to 475MB/s from my workstation to my NAS.
The speed cap at 475MB/s seems to me bottle-necked by my Samsung 860EVO SATA SSD drive.

 

[Zigourney]

Hey there,

your CPU has 16 lanes total (you can use 1x16x or 2x8x, as you described) and a separate DMI3 to Z370. All peripherals (PCIx1, SATAs, M2s, USBs) are connected to Z370.
Sometimes BIOS doesn't detect cards correctly, if needed, force PCIE to 2X 8x and you're good to go.

P.S Card is PCIe gen 2, so expect your graphics card to fall back to gen 2 too.

It appears that my GFX card did not fall back to gen2 as I was able to independently assign gen3 on the gxf card and gen2 on the 10gbe network card.

So now I am itching to upgrade my boot drive to the Samsung 970 Evo Plus m.2 NVME drive.
I have two m.2 slots on my motherboard which I believe from reading the manual, one of the m.2 slot can run at pci-e x4 speeds and the other m.2 slot can run at either SATA mode or pci-e x4 mode.

So now I have 3 questions I am hoping someone with much better technical knowledge than me can answer definitively.

1) I know my GFX card is using x8 of the CPU lanes, but is the 10gbe x540-T2 card using x8 of my CPU lanes or is it using the pci express lanes from the Z370 chipset?

2) If I install a Samsung 970 Evo Plus m.2 NVME drive in my motherboards M.2 slot, will this take up another x4 pci express lanes from the CPU or from the Z370 chipset lanes?

3) If I install the Samsung 970 evo plus m.2 nvme drive in my motherboard as well, will my 10gbe x540-t2 card and the Samsung 970 evo plus m.2 nvme drive work at full speeds? i.e. the 10gb card at x8 gen2 speeds, the m.2 nvme drive at x4 gen3 speeds, and my gfx card at x8 gen3 speeds?

My end goal is that I don't want to bottleneck the 10gbe file transfer speeds between my pc and the 10gbe card on my nas. I want the maximum possible file transfer speeds in both direction.