You complain about nonsense and than go forward and spread some on your own. You saying that SmartScreen and Defender slows down a Windows machine by a factor of 2 just makes you a nonsense clown.
Yes, I was wrong - its not by a factor of 2, more like a factor or 3 to 5. The best way to make your computer age 10 years in a second is to enable ANY antivirus. There are so many places that you can check that out if you didn't experience it, or u need me to LMGTFY ?
So you decide to double down on your wrongness? Windows Defender has a marginal impact on performance, such that for most users and most tasks it's not even perceptible.
> need me to LMGTFY
You've provided zero evidence to the contrary. The burden of proof is on you.
> As far as I can tell, as long as Windows Defender (and presumably other A/V scanners) are running, there's no way to make the Windows I/O APIs consistently fast.
This is really even a common knowledge - if you did ANY IT work, you should already know it. I can't count the number of times when server wasn't working correctly when it turns out it just has Defender on.
Yes, PC desktops commonly run AV which can impact certain common subsystems in their routine operations. This is true on Windows, Linux, and MacOS. This is perfectly reasonable for the 99% of PC users that are not programmers and power users.
> it just has Defender on
It's unfortunate Defender would come pre-installed even on Server.
Nobody uses antiviruses on Linux (except if they host a mail or file server). As far as I know most people who use MacOS do not either. It is true that a lot (most?) windows users use antiviruses but this is not an argument against the claim that it causes massive slowdowns.
> Windows Defender has a marginal impact on performance,
Oh, come on; there are issues like this: https://github.com/rust-lang/cargo/issues/5028 and the app developers do handstands in order to minimize the impact; for example, cargo guys had to redo their file closing on Windows to be done asynchronously, so they would not have to wait for Defender.