Hello Miguel, thank you very much for contacting us.
Please bear in mind that the Intel® Core™ i5-4570 Processor was released in 2013 for both the retail and OEM markets. At this point we haven’t received reports of similar behaviors in branded computers (OEM manufacturers) or custom build ones (built by end users or computer stores).
It is very difficult to address the problem you described to a processor issue. The processor is not the only difference between the Optiplex 3010 and the Optiplex 3020. We need to consider that the OPtiplex 3010 is based on an Intel® 6 Series chipset and the Optiplex 3020 is based on the new Intel® 8 Series Chipset, hence the motherboard construction is different. Possibly the 3020 also has a different type memory and components.
In the comparison chart that you quoted with the two processors, you can see that they both support the same Instructions sets (SSE4.1/4.2, AVX) and even thought the Intel® Core™ i5-4570 supports AVX 2.0 it is backwards compatible with AVX.
The commands you run in a system belong to the operating system, they were developed based on the nature of it. The operating systems are designed considering the current hardware and processor languages and architecture so we assume that Microsoft and any other software developer is up to date same as we are when making new chips.
Thinking that the new CPU is not handling properly old commands is difficult to confirm and most we can do is sharing your report with other departments to see if there is something we can recommend.