Streaming server CPU lane question

[Billybonka]

Hi I have a few questions since a while I have built a server do streaming corporate shows. 

 

Specs:

-CPU: i7 7800x 28 lanes

-RAM: 32 gb ram

-GPU: 1070ti gtx 16 lanes

-Mobo: x299 msi tomahawk

-Blackmagic Decklink duo (4 sdi inputs) 4 lanes

-NVME SSD 500gb 

-M.2 intel wifi 6 ax

 

Now I want to add an intel x550 dual nic 10gbe pcie card (4 lanes). I'm also thinking of adding another pcie capture card with 4 sdi inputs. But I'm not sure what will happen with the CPU lanes. Because I need this for my profession. The stability and performance are key.

 

Is my NVME drive or/and my wifi m.2 card taking up lanes? 

 

If i count i have 16 GPU + 4 Capture card + 4 10gbe = 24 lanes. So i have 4 lanes left for an extra capture card? if i don't need to count in any lanes for my NVME and M.2 wifi chips.

I hope somebody could help my find some answers to this question.

 

This is the info i find in my manual of my motherboard. Would this mean if i install something in the 8 lane pcie slot that my GPU would switch to 8 lanes?

 

Thanks guys,

 

 

[brob]

If I understand correctly, with a 28 lane cpu PCI_E1 always uses 16 lanes, E4 always uses 8 lanes, E6 always uses 4 lanes. That accounts for the 28 cup lanes. PCI_E2, E3, and E5 use chipset lanes; 1, 4, and 1 respectively.

 

The block diagram on page 22 of the manually indicates that the two m.2 connectors use chipset lanes. As does the Wi-Fi.

 

When contemplating placement of various cards keep in mind that devices using chipset lanes share the single DMI 3.0 connection with the cpu, essentially a 4 lane PCIe 3.0 bus.

[Billybonka]

20 hours ago, brob said:

If I understand correctly, with a 28 lane cpu PCI_E1 always uses 16 lanes, E4 always uses 8 lanes, E6 always uses 4 lanes. That accounts for the 28 cup lanes. PCI_E2, E3, and E5 use chipset lanes; 1, 4, and 1 respectively.

 

The block diagram on page 22 of the manually indicates that the two m.2 connectors use chipset lanes. As does the Wi-Fi.

 

When contemplating placement of various cards keep in mind that devices using chipset lanes share the single DMI 3.0 connection with the cpu, essentially a 4 lane PCIe 3.0 bus.

Thank you so much for this input

 

How do you know that e2 e3 and e5 use chipset lanes? Did i missed it in the manual?

 

What does the sharing of the DMI connection mean? That I will not have enough bandwidth for a scenario with a 2 capture cards and 2 nvme drives ?

[brob]

The block diagram on page 22 of the user manual provides some of the needed information.

Note the upper left expansion card, the arrow underneath traces to the chipset through a switch with the U2 connector.  On the right below the cpu note two PCIe x1 Slot and one WiFi connection tracing to the chipset. Use of the word Slot indicates the two single lane expansion slots.

 

On page 16 the Specifications has a note about PCI_E3 being connect to the chipset, (PCH in Intel parlance).

 

 

Note the bus labeled DMI 3.0 between the cpu and chipset (X299 PCH). This is the only connection between the two chips. Bandwidth wise this bus is equivalent to four PCIe 3.0 lanes, just under 4 GB/s. It is possible to saturate this connection, but it takes work.