As a PC user, you are probably familiar with the PCI Express x16 slot, which is commonly used for graphics cards and is one of the fastest connections on the motherboard. However, did you know that PCI Express X32 actually exists? You might wonder, what would you do with a slot that is twice as long as the standard x16 size?
To clarify, those numbers when we're talking about PCI Express refer to the number of lanes, not the physical size of the slot. A tiny M.2 SSD, for instance, often uses four PCI Express lanes, even though the connector is quite a bit smaller than a regular PCI Express X4-sized slot.
So, how does PCI Express X32 work? It turns out that the PCI Express standard does not support a single link greater than x16. The reason for this is that it is very difficult to actually implement links this wide in hardware. When you send data down a PCI Express link, say to a graphics card, that data is striped across multiple lanes. Doing this is not trivial, and when the data arrives wherever it's going, it has to be deskewed, meaning synchronized. Although PCI Express is a serial interface that doesn't require the data on each lane to arrive at exactly the same time, synchronizing the data still involves hardware overhead. Once you start getting past 16 lanes, it's just too much to keep up with.
Instead of having one big slot, these higher PCI Express connections use a trick called driver binding. This allows multiple PCI Express devices to talk to each other and coordinate their traffic so they can act as one big device. A PCI Express X32 link is actually two x16 links mashed together in software with the devices installed in two normal x16 slots. The performance overhead involved with driver binding for X32 isn't too bad, but if you were to theoretically go up to say x64, you'd likely need more hardware as at that point, you just have too many transactions for your poor system to handle.
The appeal of having this many PCI Express lanes isn't so you can do something like squeeze more performance out of your graphics card. Instead, driver binding is used in applications where all the bandwidth you can get is appealing. You often see X32 links in certain kinds of networking cards, mostly for server and data center use.
In conclusion, while PCI Express X32 might seem like an overkill for personal use, it has its applications in the world of data centers and networking. However, for the average PC user, the PCI Express x16 slot is more than enough for their needs.