PCIe, 8th gen Intel motherboard, GPU, and NVMe question

hellothere_1975

Distinguished
Jan 29, 2011
6
0
18,510
Hey guys and gals,

I plan on updating my computer from a 2014 build, and the number PCIe lanes I had available was never really looked into all that much. But now I guess I'm paying attention a bit more and I want to run my thoughts on this for the community to see if I’m thinking correctly. I plan on building a smaller computer, making use of a mini ITX board and installing that into a small case (for whatever reason, I just like the idea of having somewhat of a powerhouse in a tiny box). I’ll likely be getting a i5 8600 or i7 8700 (since the case will be quite small, I don't think I'm going to overclock--I've actually never needed to overclock because of gaming--I just did it for fun when I'd make my build just to see what happened).

From what I can tell, those CPUs afford 16 PCIe 3 express lanes. I plan on using an m2 NVMe SSD and one graphics card. If I understand things correctly, the NVMe can use up to 4 lanes and the graphics card can use up to 16 (making a total of 20), and the motherboard chipset can add additional lanes, but at a cost (i.e., those additional lanes aren’t quite as fast as the direct lanes found on the CPU). At this moment I find B360, H370, H310, and Z370 boards are my options, but the h310 is out because I’ll be using an NVMe drive.

Question: it looks like the h370 has 20 lanes available and the B360 has 12 max lanes. With the addition of the CPU, am I right in thinking that the B360 would have a total of 28 (16+12)? If I had one graphics card using 16 and one NVMe using 4, that is all I need, correct? If I’m using only one GPU (I’m assuming that would take up the 16 available lanes of the CPU), then I only need 4 additional lanes, right? Or is there more to the story? Thanks for your time.
 
Solution
It's more or less what you say. With the clarification that the 16 lanes of the CPU are for the first graphic card always. Therefore it is more practical not to consider the CPU lanes or the first graphics card. (and only if you plan a mini-itx).

The HSIOs are used by USB3, Ethernet, extraSATa, NVMe and PCIe. In general, it is the mobo manufacturers that have to adapt to not exceed the limits. With a mini-itx board it is difficult to overcome the limitations but I recommend reading the specifications of the mobo you want to buy (it can happen, for example, that it has two nmve connectors and if both are used, some SATA is disabled) ...

If you are not going to do OC discard the Z370 because it is more expensive, and being older does...
It's more or less what you say. With the clarification that the 16 lanes of the CPU are for the first graphic card always. Therefore it is more practical not to consider the CPU lanes or the first graphics card. (and only if you plan a mini-itx).

The HSIOs are used by USB3, Ethernet, extraSATa, NVMe and PCIe. In general, it is the mobo manufacturers that have to adapt to not exceed the limits. With a mini-itx board it is difficult to overcome the limitations but I recommend reading the specifications of the mobo you want to buy (it can happen, for example, that it has two nmve connectors and if both are used, some SATA is disabled) ...

If you are not going to do OC discard the Z370 because it is more expensive, and being older does not have native support to the latest versions of usb 3 gen 2.
 
Solution