FUNDAMENTALS OF COMPUTER

Detailed explanation-1: -Wikipedia states that the theoratical output through a single lane of PCIe 3.0 × 8 port is around 985MB/s. That’s around 7880 MB/s or around 7.69GB/s for 8 lanes. 40G QSFP+ means 40Gb/s or basically around 5GB/s output.So i.e.10GB/s if you combine bandwidth of both of the output ports.

Detailed explanation-2: -PCIe x8: These can also fit in an x16 slot, but they have half the PCIe lanes and are most commonly used for GPUs or for M. 2 NVMe SSD expansion cards. PCIe x16: The largest slots on the motherboard, these slots are used for cards that require a high bandwidth like GPUs.

Detailed explanation-3: -PCIe 4.0 is twice as fast as PCIe 3.0. PCIe 4.0 has a 16 GT/s data rate, compared to its predecessor’s 8 GT/s. In addition, each PCIe 4.0 lane configuration supports double the bandwidth of PCIe 3.0, maxing out at 32 GB/s in a 16-lane slot, or 64 GB/s with bidirectional travel considered.

Detailed explanation-4: -PCI Express Theoretical Max Bandwidth For our test, we’re looking at PCI-e Gen3 x8 vs. PCI-e Gen3 x16 performance. That means there’s a 66.7% difference in bandwidth available between the two, or a 100% increase from x8 to x16.