Gadgets

L3 cache sits on the same chip as the CPU, its incredibly fast and usually pretty small (96MB in this example). This software turns that little bit of memory into a ram disk. Why not make the L3 cache bigger I hear you say - cause its expensive.

Also, the cache is usually used for code so if you use the cache for data your software will run slower.

There are a bunch of parts of a PC that all have the same job of storing data, but the speeds at which they can do that are wildly different.

• HDD: slooooooooooooooooooooooooooooooooooooooooow
• SSD: sloooow
• RAM: faaaaaaaaaaaast
• CPU cache: faaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaast

"So why not get more of the fastest stuff?" Because a) it's way more expensive than the slower options and b) for CPU cache specifically, there isn't enough physical space on the CPU die to fit much more. (This is why AMD's "3D V-Cache" was a breakthrough, being able to fit more cache on the die.)

This guy decided to take his CPU cache, and make it pretend to be an SSD. So the tools designed to check SSD speeds try to measure it and report insanely high numbers (because it's faaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaast)