When considering upgrading, the best results will derive from starting with:
1. What are the principal uses? The best hardware for video editing is different from 3D CAD, development, or server uses.
2. What is the performance deficit? What should be faster?
3. Is this used professionally?
4. What is the current specification? CPU, RAM, GPU, drives etc?
5. What is the budget?
6. When is the current system likely to be replaced?
When stating; "Just upgrade all", does that literally mean, potentially replace the CPU(s), RAM, GPU, drives etc- anything that improve performance?
In my view, z820 can be completely useful at a good level in 2021 and beyond. Given the outrageous prices and unavailability of new hardware, worth upgrading- up to the appropriate point.
There are by the way, 28, z820's on Passmark of the 705 tested using 256GB of RAM- almost 4%.
I recommend downloading, installing and running the 30-day free trial of Passmark Performance Test and along with the list of the hardware in the subject report the test results which can reveal the weak hardware or problems.
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