**System Information**
Operating system: Windows-7-6.1.7601-SP1 64 Bits
Graphics card: GeForce GTX 980/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 446.14
**Blender Version**
Broken: version: 2.90.0 Alpha, branch: master, commit date: 2020-06-08 15:55, hash: `rB9f7d84b656fb`
Broken: 2.83.0 (release)
**Short description of error**
The issue is a bit hard to describe, so sry for that.
Whats happening in my scene is that I use a monkey mesh for example with a setup of modifiers. I link-duplicate it and use a different setup of modifiers on this mesh.
What I see are performance issues while modeling on one of these monkeys, appearently coming from the modifiers of the other monkey.
My feeling is that edit mode is handling/updates modifiers of both meshes at the same time.
**Exact steps for others to reproduce the error**
{F8609042}
The two monkeys have linked mesh data. Left has Bevel modifier, right has Subsurf.
//Steps to see the slowdown//:
1. Left Monkey (Bevel): Go into Edit mode, grab a vertice and move around to check editing speed
2. Right Monkey (Subsurf): Do again on this one, it should be slower in comparison. (if not noticable on your system, subdivide the mesh manually to increase geometry, keep modifiers)
3. Left Monkey: Turn "show_viewport" for Bevel modifier off.
4. Right Monkey: Check editing speed, it should be a lot faster or very smooth.
**Problem**: The Bevel modifier of the left monkey negatively affects the editing speed of the right monkey.
Notice another (related?) problem: Subsurf isnt even visible active on the right monkey, but slows down regardless.