Jim, can you give some insight on what PCI lanes are actually used for? I know a video card can use up to 16 but that seems unlikely to be necessary for a DAW system. And the NVMe disks use 4 I think? Struggling to see how 28 lanes would be limiting even with a seemingly excessive 5 of those. But that just means I must be missing something.
ALL PCIe hardware uses PCIe lane/s.
The latest generation of SSDs (U.2, M.2, and PCIe) each uses 4 PCIe lanes.
The newest USB-3.1 controllers are PCIe Gen3 x4 (4 PCIe lanes).
Whenever you see a peripheral with PCIe x16
, that means it uses 16 PCIe lanes.
Let's use a new Skylake Extreme 7820x as an example (provides 28 PCIe lanes):
Your video card will use 16 PCIe lanes.
That leaves 12.
Now let's say you want to run two PCIe x4 SSDs.
You're down to 4 PCIe lanes for all
If your build stops there, you're likely fine. But sometimes it's not that simple. ie: If you're running a CPU with 28 PCIe lanes, some M.2 Ultra (PCIe x4) controllers will be scaled back to x2.The motherboard manufacturers don't always put this useful tidbit in their manuals.
So... the SSD that's capable of sustaining 3200MB/Sec will yield 1600MB/Sec.
In this example, the workaround is to put the M.2 Ultra SSD on a PCIe adapter card... and put it into a full-length slot where it has the necessary 4 PCIe lanes.
On a simpler build, it's a moot point.
On a build where you want to leverage massive bandwidth, 28 PCIe lanes is limiting.
Getting outside the "Audio/DAW" realm, if you're running a pair of video cards, 28 PCIe lanes is extremely limiting.