It is not that simple, there could be jumper settings that are needed but not present or there could be traces that are needed for the real cache to work but might not be there at all. It is best to avoid such boards or live to make do with what performance they offer.

Understood. It was a curiosity, given I picked up the 486 box for less than ten dollars at a thrift store back around 2008.

Not only will the M918 support real cache, but if you can find the (fairly rare) chips necessary to do so, it'll actually take up to 1MB.

Now, that's not saying it'll be a simple matter to upgrade it. Obviously you'll have to remove the fake chips and install the real ones (and I would strongly recommend using sockets), and also fix any jumpers which may be hardwired or unpopulated. But there's also a chance you'd need to change the BIOS. I'm not sure about the M918 specifically, but some of those fake cache boards actually had hacked BIOSes that disabled cache entirely, in which case you'd need to find and install one of the versions that didn't do so... and often on the boards with hacked BIOSes, the BIOS chips are also soldered-on.

But if you feel adventurous and have decent skill at soldering, it's certainly doable.

Okay, looks like the BIOS chip (with a sticker that says "AMIBIOS" with a model number of AD0591971) is actually SOCKETED. This intrigues me highly. What is a board with fake cache chips doing with a socketed BIOS chip?