1, Visual studio shouldn't slow down after opening 3-4 instances

It does already with 2

You get to multiple instances?

Its rarely the number of instances in my experience but rather once you keep them open for a week or two or do debugging with to much recursive code (200+ levels of stacktrace makes it pretty sad)

But I often have 3-5 instances open along with sql manager, a few vscode and half a dozen browser windows with multiple tabs.

But it does eat up a bit of memory.

And also it depends on the project.
Legacy webforms pages with 3000+ loc markup es a killer for it.

You might have to switch of some functionality for very large projects.

@Voxera for me it's very common for visual studio to start consuming cpu constantly for no reason if I have two instances open.

@electrineer do you use any extensions like resharper, I know that can eat a lot.

On the other hand we hade quad core cpus and 64Gb memory so I might just not have hit the ceiling yet ;)

@Voxera no resharper. I have a dual core at work. It was already two generations old when I got it.

@electrineer is it a very large project, like 10 000’s of files or are you using the outline scrollbar?

If the later, try disabling it for markup, we have had it lock up on large markup with that.

@C0D4 yes! with intellisense completely hiding

@Voxera it's completely fine with only one instance. Well it gets a bit sticky when working with a class that has hundreds of classes inside it.

@Voxera opening medium/ small projects not excluded once you get to your 3rd instance. intellisense & debuging becomes terribly slow. I always had to use 'Start without debugging' then 'Attach to process' for my web project.

once my frustration level hit a 100, I restart all instances.

@heeyahnu I dont know what you consider small or medium but in my case the solutions contain 6-10 projects with 100-300 “pages” or views and a few hundred service and repository classes each and the maybe a thousand data classes.

And I can have up to 5 or 6 open without any direct problems.

If I get a problem its often just one of them and mostly if I have been doing a lot of webforms markup.
And I use resharper.

@Voxera And whats your dev environment like ?