PCIe (PCI Express)
The high-speed interface connecting GPUs, SSDs, and expansion cards to your CPU and motherboard. Each generation doubles bandwidth per lane.
What is PCIe?
PCIe (PCI Express) is the high-speed serial interface that connects expansion cards — GPUs, NVMe SSDs, network cards — to your CPU through the motherboard. It's the data highway between your processor and your peripherals.
PCIe uses "lanes" (x1, x4, x8, x16) — more lanes means more bandwidth. GPUs use x16 slots (the longest ones). NVMe SSDs use x4. Each generation doubles the per-lane bandwidth:
- PCIe 3.0: ~1 GB/s per lane (x16 = ~16 GB/s)
- PCIe 4.0: ~2 GB/s per lane (x16 = ~32 GB/s)
- PCIe 5.0: ~4 GB/s per lane (x16 = ~64 GB/s)
Frequently Asked Questions
Does PCIe 5.0 improve gaming performance?
Barely. Current GPUs don't saturate PCIe 4.0 x16 bandwidth during gaming. Benchmarks show 0-2% FPS difference between PCIe 4.0 and 5.0. Don't pay a premium for PCIe 5.0 — spend it on a better GPU instead.
Are PCIe generations backward compatible?
Yes. A PCIe 5.0 GPU works in a PCIe 4.0 slot (at PCIe 4.0 speeds), and a PCIe 4.0 card works in a PCIe 5.0 slot. You never have a compatibility issue — just a potential bandwidth reduction.