Does disabling VT-x enhance stability/performance?

Currently I don't have much need for virtualization.

Anecdotally, my friend's old computer had BSODs a few times a week, but after disabling VT-x the BSODs didn't appear anymore.

In general, will disabling VT-x will make the computer run faster/more stably?

If you don't need it, disabling it via the BIOS is fine.

In terms of stability, having it enabled or disabled shouldn't hinder/benefit the stability/performance of a PC. If you're not using software that is making use of virtualization, it should not affect performance.

Are you sure your friend didn't make other changes in the BIOS in order to try and fix his problems? Maybe he had an unstable CPU or RAM overclock.

I've had virtualization both enabled and disabled and when I've run benchmarks and stress testing applications, I've never seen a performance drop or a stability issue.

I know it's an old thread, but it's still on the top of Google results. So I'll throw my two cents.

I had a fx-6350 which was working fine, but right after I enabled virtualization windows themselves become unstable. I was getting freezes and bsods every couple of days, that said after disabling virtualization the issues persisted. I couldn't fix it no matter what I did, so I bought a new PC.

A Ryzen5-2600, it was working perfect. But one day I needed virtualization, so I enabled it. And here I am again, games freeze this time. Every time after it runs for 15~ minutes a game will freeze. Since the only thing I did recently was enabling virtualization, I disabled it. No more issues whatsoever.

I can't say with 100% certainty it's virtualization related problems, but it seems like it to me.