Understanding PCIE lanes for storage

[sniperone]

Just finished putting together my new computer with a 12700k and z690 motherboard and rtx 3070 and have gone full nvme with 2x 1tb and 2 x 2tb drives populating all sockets
Now my old build i was running with a 2 x 4tb hdd and looking forward on the new build and rather than swap out drives for larger ones im alittle baffled when it comes to PCIE lanes and storage
my understanding is 20 lanes for cpu taken by gpu and one nvme . Not sure what im left with for future upgrade ,also looking to install a dual thunderbolt card so that will take up lanes also .
Just thinking forward as i do heavey video and photo work plus games and storage fills quickly and rather than swap out drives was looking at a controler card to add more nvme storage but not sure how it all works

 

[Haz123]

Well the Intel official info is totally useless as expected.

Intel® Core™ i7-12700K Processor (25M Cache, up to 5.00 GHz) - Product Specifications | Intel

Intel® Core™ i7-12700K Processor (25M Cache, up to 5.00 GHz) quick reference with specifications, features, and technologies.

www.intel.co.uk

Do not know why I posted it and I suggest you ignore it.

Far more useful is Guru3d showing the Z690 chipest diagram on this page.

Core i5 12600K processor review

With six performance cores and four energy-efficient ones, the Core i5 12600K might become the most budget-friendly and really well-performing Alder Lake series processor. It offers heaps of performan... 12th Generation Core series processors

www.guru3d.com

The cpu has 16 PCIe 5.0 for the gpu and a then 1x4 PCIe 4.0 for an Nvme. This is what you have said above but without the diagram you do not see that the Z690 chipset then gives you a lot of extra lanes that can be used , upto 12xPCIe 4.0 upto 16xPCIe 3.0 and a other things as well. It is best to look at the diagram tbh.

Without knowing just what NVME drives you are using we cannot say if you have saturated the PCIe 4.0 bandwidth. I hope some of the drives are pcie 3.0 so you have spare capacity for your thunderbolt card. You will need to look at your motherboard manual to see what happens when you plug in a pcie 4.0 card into mobo , it may disable or limit some of the cpu lanes or it may run through the chipset so not entirely sure.

 

[sniperone]

All the nmve drives are samsung 980 pro 4.0. So it looks like i have used all 12 PCIe lanes on the chipset and only have the 16xPCIe 3.0 lanes left .

 

[Tetras]

All the nmve drives are samsung 980 pro 4.0. So it looks like i have used all 12 PCIe lanes on the chipset and only have the 16xPCIe 3.0 lanes left .

It is best to check the manual like Haz123 said, because the manufacturer can wire up the lanes however they want and they're potentially shared with other PCI-E devices/expansion slots on the board. Only the manual will tell you which lanes belong to the CPU, too (though it's usually the closest m.2 slot, above the graphics card).

If you get an M.2 add-in card and use an expansion slot intended for a graphics card, then I believe it needs to support bifurcation, because otherwise not all the add-in card's M.2 slots will work properly when populated. It's quite common that you will lose lanes on the primary PCI-E slot too, but in theory there should be enough lanes not to impact performance.

 

[sniperone]

Thanks guys have emailed gigabyte customer service and they tell me the thunderbolt card will use 4 pcie 3 lanes so that leaves me 12 pcie 3 lanes for storage so could in theory add another 3 gen 3 nvme drives should i need them .