Is x2 x4 x8 actual hardware or is it flashable

Is the term AGP x2-4-8 actual hardware standards or is it something you can flash, and if so would it help performance?

It's hardware, on both the motherboard and the video card. Along with the hardware the bios has to support the different speeds. You can for example force an 8x AGP motherboard to work at 4x through a BIOS setting. However you can't make a 4x card or MB run at 8x if all it supports is 1-2-4.

Edited to add that benchmarks show 4x is about as good as it gets with AGP. 8x, although it has double the theoretical bandwidth, is only a wee bit faster.

I have seen 8x outshine 4x by more than a wee bit, but you need to have a use for all that bandwith...generally only happens if you are having to use system memory constantly, or if the code is written to split the load between cpu and gpu more evenly, despite the fact that the gpu is almost always more powerful.