Bug/Issue Intense Lag/Stuttering Issue

Since I updated to the beta, I've been having a constant lag/stuttering issue with my game. And now that multiplayer is fully released I can't just revert back to 1.2. Every time I load up an old save or a new one, every 2-3 seconds the game stutters and freezes for a moment before continuing. Sometimes the game will just freeze all together for a solid 10-15 seconds which is insanely frustrating. It doesn't necessarily make the game unplayable but it makes everything I do a hassle. I have absolutely no idea what's causing it. At first I thought it was the mods I'm using but I have since completely uninstalled smapi and reinstalled stardew. So all the files for the game should be brand new. Can someone please help me figure this out I haven't been able to play for weeks because of this.

 

Windows is not going to give you maximum performance out of that CPU and Mac will be even worse.
What you need to do is install Xubuntu 18.04 (get used to that then migrate to Lubuntu).
You want to get the Ubuntu Kernel update utility and use kernel 4.14, currently its at 4.14.60; it's the most stable desktop kernel for modern cpus.
After bios loads you press ESC and then pick advanced, a choose boot with 4.14.60 as opposed to boot with 4.15;basically the number after the second dot tells you how mature/stable the kernel is. I can even help you configure the firewall for multiplayer. However, I've noticed that on Gog anyway, multiplayer is limited to LAN parties.

On Windows try rebooting in safe mode, check your task manager to make sure your CPU usage goes way down after boot, even if it does so in regular mode, still boot in safe mode. Before you do that, create a new admin user and install the game in there. As for coop, if you aren't using ethernet on LAN latency can cause what you describe. Also don't think Windows Stardew will play nice for Linux Stardew or that Windows Stardew will play nice with Windows Stardew; wrong. Windows is the least immutable when it comes to system configuration; another way of saying everyone's windows pc the OS is configured differently; especially if the OS of the Windows PC in question is less than Windows 10 which much improves in this area, but is technically still plagued especially if the Windows 10 build is not 1709 (The best build).

I should add, I have used the Mac and Linux build of Stardew 1.3 Final (August 1st release) and no single player lag, some multiplayer lag even though I am using the best configuration and freakin cables.