Its not really a bug, just the way the engine works.

The blood particles are entities, and the dying animation creates a lot of them: https://gfycat.com/DeficientSadChimpanzee

In the engine, any entity search needs to iterated through all entities on the 'Advanced tile', which is 2x2 tiles.

The fire needs to check each tick (or every few ticks) to see what to damage... so it iterated through all the entities (including thousands of particles).

The biter pathing/collisions needs to iterate through all the entities as they walk through the fire.

So the result is the iteration takes a very long time, because there a bajilions of them: ...

We are aware of the problem with flamethrower turrets and UPS drops, it is to do with the blood particles (which are entities).

We have a plan, and the results are already very promising.

This mod will do you: https://mods.factorio.com/mod/DeleteEmptyChunks

Its still in experimental, so unless you opt-in you won't get the update.

Saying that, we will probably mark it stable relatively soon, so nothing to worry about.

Bugfixes

• Fixed a crash that would happen on loading certain saves made in previous versions. more
• Fixed entity selection could desync from mouse cursor when switching to cutscene controller in multiplayer. more

Use the automatic updater if you can (check experimental updates in other settings) or download full installation at ...

Ah right, in-game changelog! We don't currently have link support in-game

The game wasn't finished at the beginning, still working on a way to traverse LQG spin foam in just the right way to send a USB drive with the full game back to 2013.

Characters that don't have any player attached to them.

The links in the changelog are clickable, and you can middle-click the links to open them in a new tab.

Features

• Added interface option to adjust the number of shortcut bar rows that are visible on the screen.
• Added ability to shift click a research in the technology screen to start that research.
• Allowed setting filters with the ghost cursor.

Changes

• Biters and Spitters will no longer collide with other biters/spitters. (...

Something like that: https://gfycat.com/RichForthrightHyena

Yes, it increases performance.

We will release it as experimental, but we don't anticipate taking a long time to mark the release as stable.

Your graphics card is no problem, but your CPU is pretty old.

If you want better UPS performance, I would recommend upgrading to a modern Ryzen or Intel chip, with some high performance DDR4 RAM

Nice catch, I will fix it for the next release

The mods should be updated, 0.17.69 has been released for over 2 weeks now