Based on what benchmarks?
The i5 8600 should be a ~30% increase in single-threaded performance, and a ~50% increase in multi-threaded performance—simply because it's better architecture and has more cores.
https://www.guru3d.com/articles_page..._review,7.html
However, you can spend almost the same amount of money on an AMD 2700X and get, arguably, even better performance when it comes to multitasking. Obviously, a full system upgrade comes at an increased cost and I don't know what the budget is, but here's a quick build to give you an idea - https://pcpartpicker.com/list/mQzbD2
You could always get a super cheapo motherboard, but I personally hate doing that because, in my opinion, you shouldn't really cut corners when it comes to electronics if you expect efficiency over a longer lifespan. I would also like to put a 240/280mm AIO cooler on that chip, but that is more money and requires that your case has a place to mount it.
I would say yes.
The 2070 is about two months old, and so I doubt there are many (if any) deals on a new GPU, but while it's the better choice of the two GPUs you listed, that 3770K CPU is going to, undoubtedly, hold it back.
Connect With Us