AMD released the Ryzen 5 2600 in April 19, 2018 which was a Second Generation Processor from AMD Ryzen 5 lineup. It was launched at the price of $160 and now you can find it for $120, there is also alternative with literally the same - Ryzen 5 1600 AF (12 nm refresh ) which was the upgraded version of Ryzen 5 1600 AE and came at -$90 but performed much better. On the other hand AMD launched the Ryzen 3 3100 on April 21, 2020. The original price at launched is $100.
Specifications
Ryzen 5 2600/1600 AF
click here to buy Ryzen 5 2600/1600 AF
The Ryzen 5 2600 is second generation AMD Ryzen Processor which is based on ZEN+ Micro-Architecture which is 6/hexa Core CPU which comes with the support of Hyper-Threading so it has 12 Cores. It comes with the Base Clock Frequency of 3.4 GHz and can be overclocked upto 3.9 GHz. It comes with 16 MB l3 Cache and is built on 12 nm Technology. It has the TDP of 65 W and can be paired with any AM4 Socket Mother-Board like B350, A320, B450, etc. It can support up to 64 GigaBytes of dual channel 2933 MHz RAM ( the RAM capacity differes from Motherboards to Motherboards ). It requires a Discrete Graphics Card because it does not have any Integrated Graphics Card.
Ryzen 3 3100
The Ryzen 3 3100 is a quad core CPU which has Hyper-Threading in it and comes with a Base Clock Frequency of 3.6 GHz which can be overclocked up to 3.9 GHz on all cores. It is an unlocked Processor It is a third Generation Processor so is it based on ZEN 2 Micro-architecture and Manufactured on 7nm Process. Along with 16 MB of L3 cache, it has a TDP of 65 W. It supports the AM4 socket and can be paired with any good AM4 socket Mother-Board like B450 tomahawk, B450 motar, x470, x570,etc. It supports a Maximum of 64 GB DDR4 RAM clocked at 3200 MHz in dual channel. It does not have any integrated graphics so you need to pair it with a dedicated Graphic Card.
Benchmarks And Stuff
No test is a test without Benchmarks, so I have finally tested this CPU to find the results. I have paired both these CPUs with a RTX 2060 Super ( anything above will be bottlenecked by this CPU ) and 16 GB DDR4 RAM @3000 MHz ( 3200 MHz would perform slightly better ). Cinebench R15 and 5 games are tested at 1080p resoltion on Ultra settings.
Now Both the CPUs performed perfectly and there was no bottleneck in any game. The Ryzen 3 3100 scored more FPS in games compared to the gaming and Single Core tests, thus proving the Ryzen 3 3100 is better than Ryzen 5 2600/1600 AF in gaming but the Ryzen 5 2600 is not bad, it is better than Ryzen 3 3100 in Multi Core tasks like streaming, rendering and editing as it scored more points in Multicore tests.
My Thoughts
Now at the end I will say both these Processors are really good CPUs for their respective price and if you are gamer and need a Bang For Buck level CPU then Ryzen 3 3100 is for you, I have used it for over 3 months and its amazing, it can also handle heavy Photoshop work easily. If you are getting it for $100-$110 then go get it. Then the Ryzen 5 2600 is also a good CPU is you want stream while gaming and do Photoshop work then it is better than Ryzen 3 3100 for you.
In the end if you are a gamer and will do gaming more than anything then get the Ryzen 3 3100.
OR
If you are a multitasker and you can not get the R5 3600 then get the Ryzen 5 2600.