Inquiry about PCIe technology
Inquiry about PCIe technology
There is a limited number of lanes depending on the chipset and they can be split in different ways. Lanes get used up by SATA ports, USB ports, and other peripherals, that's why you see such wide variation. In my opinion, things have taken a step back during the past decade. It used to be you'd get multiple x16 slots, and now you get just one. And SLI is gone completely. A lot of manufacturers are reducing their USB ports too.
Imagine water pipes carrying data as water, and PCIe lanes as the pipe itself. A 16-inch pipe can handle more flow than an 8-inch one, naturally being larger too. Sometimes connections double on x16 slots or you cut ends to fit cards with x16 slots, but speed is still limited by the connection. For B550 systems, using just one 16-inch inlet pipe while having several 4/8/16-inch outlets lets each outlet reach its rated performance, rather than being constrained by the total input capacity.
Lanes refer to physical connections that allow data to move between devices. Each generation offers more lanes with faster speeds, making transmission quicker. The main challenges for motherboard designers come from market needs and chipset constraints. They must balance performance with cost, space, and layout considerations. Adding more lanes increases complexity due to additional controllers, switches, and PCB requirements, which also raises expenses. This explains why many boards limit the number of lanes despite technological advances.
The variation in slots comes from the pin count, which determines the number of lanes and explains why some slots differ in length. An x16 slot offers the most pins and the longest length, while x1 has the fewest pins and is the shortest. Slots can physically exceed their designated pin configuration—for instance, an x16 slot might be wired for x4 or x8, which is more typical. This applies independently of PCIe generation upgrades, which increase bandwidth through different methods.
They often boost bandwidth for hard drives without good reason. NVMe supports four lanes, but one or two would be sufficient. Those lanes could serve extra PCIe bays or USB connections. Some boards offer several 4x NVMe ports, while the second PCIe slot is just single lane, rendering it practically useless. They might benefit from consolidating to a single 4x NVMe and using the remaining lanes for other purposes. A straightforward 4x PCIe setup would be more practical.
NVME ports can be adjusted to standard PCIe quite simply. I hope they provide additional lanes for consumer devices. The lane count hasn't kept pace with today's requirements. It doesn't matter whether they're slots on the board, NVMe, Oculus Link, or another format—just more than 20+4 lanes from the CPU without needing to dive into Threadripper, Xeon, or EPIC.
To increase PCIe lanes from the CPU, you must install an additional PCIe controller on the CPU die. This requires a more costly silicon chip, more pins inside the processor, a larger socket, and complex trace routing. The trade-off between AM4 and AM5 involves higher-performance CPUs paired with more expensive motherboards due to larger sockets, increased pin counts, and tighter routing challenges. Manufacturers reduced costs by sharing silicon dies across CPUs with built-in PCIe, SATA, and USB features, and by using a 12-14nm process for the die while the main CPU operates at a lower 7nm.
They could definitely handle it. This approach really focuses on dividing the market. Back in the day with the northbridge built into the CPU, we used SATA/PATA drives which required far less input (just one PCIe lane would suffice). Nowadays, storage is mostly PCIe-based, and you either choose to run everything through the chipset or switch to a workstation/server setup. I’m feeling frustrated. I’d like a single PC to manage everything. I don’t need a NAS, and I’d prefer all my storage to be flash-based, though finding affordable SATA SSDs is becoming tough. I’m just one of the few who see this way.