PCI Express

Pineapple Communications Instituional Express

They made a movie about this, wasn't very good.

Devices

Really everything runs on these mad boys. Some devices are straight to the chipset and others are straight to the processor.

NIC

network cards are common PCI devices. Gets you that 10 GIG or off the Realtek drivers in FreeBSD

Can ever get yourself some fiber modems out of your stndard Pentium 4 computer if you really wanted to (I wouldn't try it though)

Graphics Cards

Yup you know it.

It gets pretty interesting now w/ Graphics cards w/ x1, x4, x8 & x16 configurations, passthrough and bandwidth surplus on PCI 4.0

Some eco hippy somewhere is crying that VFIO based home servers aren't a must at the center of every multi family household that plays games (not slot machines)

M.2 Jazz

Your NVME, Wifi, Coral TPU's all run on these but they are just PCI Expresssssexy at the end of the day

Whatever else

Parallel ports, your dog skip, a NUC Extreme Compute Units

PCI lanes are dope, we should really be spending more time worsehiping these beautiful concepts.

Virtual PCIE Lanes

I asked ChatGPT for the fun of it, here's what it had ot say.

Bandwidth Considerations:

PCIe 4.0 lanes offer double the bandwidth per lane compared to PCIe 3.0. So, theoretically, a single PCIe 4.0 lane can handle the same amount of data as two PCIe 3.0 lanes. However, this does not mean you can simply 'split' a PCIe 4.0 lane into two PCIe 3.0 lanes. The bandwidth is a product of the physical properties of the lane, including factors like the number of wires, signal integrity, and the physical layer design. Physical vs. Logical Lanes:

PCIe lanes are physical connections consisting of pairs of wires (transmit and receive). You can't physically split these into more lanes without additional hardware. Virtualization in computing typically refers to logically partitioning resources (like CPUs, memory) and doesn’t apply to the physical splitting or doubling of hardware resources like PCIe lanes. IOMMU and Virtualization:

IOMMU is a technology that allows the safe and efficient virtualization of memory resources, not the expansion or conversion of PCIe lanes. It’s used to remap physical memory addresses to virtual addresses, primarily for the sake of security and device isolation in virtualized environments. PCIe Switches and Expanders:

To increase the number of available PCIe lanes, PCIe switches or expanders are used. These are physical devices that take a certain number of PCIe lanes and split them into more lanes. However, these solutions do not increase the total available bandwidth. They simply allow more devices to be connected, each potentially operating at a lower bandwidth. Practical Limitations:

The idea of converting PCIe 4.0 lanes to more PCIe 3.0 lanes is limited by practical and physical constraints. It's not just a matter of software or virtualization; it requires specific hardware designed for such purposes. Additionally, there are considerations like latency, protocol overhead, and controller capabilities that affect how PCIe lanes function and perform.

In summary, while the theoretical bandwidth of PCIe 4.0 lanes might be equivalent to double that of PCIe 3.0, the practical application of splitting or converting these lanes is not feasible through virtualization or IOMMU. It is bound by the physical and electrical properties of the PCIe lanes and the limitations of current technology. To expand the number of PCIe lanes, hardware solutions like PCIe switches are typically used, but these do not increase the total available bandwidth.

PCI Science GUY

I wonder if I'm just a PCI lane attached to a really powerful NUC. Which I could be Lithography Fluid