If you’ve everinstalled a CPU(or watched it done) you’ve almost certainly seen a small square object slot into a flat socket on a motherboard. For a brief time in PC history, though, desktop processors looked like NES cartridges, sometimes with fans strapped to them!
The Rise of the Slot CPU: Pentium II’s Debut
In May of 1997 Intel launched the Pentium II. Rather than launching these processors in a package where a grid of pins were inserted into a grid of holes in a motherboard socket, the “Slot 1” design used an edge connector. This made it more like a graphics card, which to this day still used a processor on card design.
Even back then, the competition between Intel and AMD was red-hot in theCPU market, so unsurprisingly AMD soon followed with it’s imaginatively-named “Slot A.” Hey, “1” and “A” are both at the top of their respective stacks! Since AMD played follow-the-leader so swiftly, you’d be forgiven for thinking that there must have been something to this approach, and you’d be right.
Why a Slot CPU?
There are genuine benefits to moving your CPU onto a card format like this. How important those benefits in practice are debatable, but they are undeniable:
Even today, Slot 1 Pentium II CPUs seem somehow more futuristic than even the latest CPUs of today, so you can imagine how we thought this was going to be what CPUs would look like going ahead. What actually happened is that some Pentium III CPUs used Slot 1, but that was the end of it, with Socket 370 taking the PIII back to a traditional socket design. Since then desktop CPUs have generally used a socket design, increasing the number of pins. The major change was moving the pins from the CPU package to the motherboard, so if you bent any pins, at least the CPU would be OK.
Why Didn’t Card Slot CPUs Work Out?
Even in hindsight, it’s hard to pinpoint any single factor that killed off the idea of a CPU card. By the early 2000s, both Intel and AMD phased out the slot-style CPUs in favor of the more familiar socket approach. I think this shift was largely driven by the need for more compact, cost-effective, and efficient designs. Three key factors are responsible, in my opinion:
The socket design for CPUs still seems to be the best way to go about it, but we shouldn’t make the mistake of thinking we’ll never see another approach. CPUs are once again heading for a number of technological walls and new and radical CPU designs might need a different way to connect to the rest of the computer. Half the fun of being a computer geek is seeing what wild new approach engineers come up with!
