> Should I disable Intel® Hyper-Threading Technology to get a better Lisp/FAS/VBA performance?
That is more of a software question, so worth more of a software answer: try it both ways with exactly the same, representative workload, and time it. Also, check what happens with other important tools you use: some programs get faster with HT, others get slower.
More generally, upgrading hardware only speeds up things linearily, and only if the thing you change is the bottleneck. If you have an exponentially growing problem, no amount of hardware you throw at it will help much. So, if your computer performance is otherwise acceptable, it is time to take a look at your problem software: is the task inherently expensive, or are you using inefficient algorithms.
In software optimization, the most important task is measuring the performance at detail level: quite often the hot spot is hiding in some odd place.
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