If I were to guess I’d say that it’s the CPU. The game is currently most likely CPU bound due to the unoptimized AI system.
The FPS is really critical for the combat. I enjoyed the combat in Alpha 0.4 once I got the timing right, but then the performance drops and stutters in Alpha 0.5 made it quite unplayable. The Beta greatly improves the performance so the framerate is again smooth and the combat feels pretty awesome when it works. Parry/counter/parrry/… sequences are fun. I can land one simple combo quite reliably. Parrying and dodging works, mostly.
Unfortunately, it’s hard to get the block and dodge right. There is no indicator what you did wrong, that is, if you press the button too late or too early. If you block and don’t get the timing right, Henry does not react and you just get pummeled. It is very tricky to do this outside of the arena because the consequences are so severe. One mistake and the fight is pretty much lost. This on the one hand is good, making the combat with even a single enemy meaningful, but with the unpredictability it becomes a bit frustrating. Similar with combos, I can only land the first combo out of the 3 showed in the tutorial. I don’t know why… It also looks that the timing for blocks is different if the opponent has a short sword. This definitely doesn’t help.
Many things are currently quite broken, especially NPC’s reactions. There are big delays before they react to your actions. The combat lock often does not engage once you attack them or they start attacking you and then there is no way to defend or attack.
In the end, it is probably better to wait for an update which fixes some of these bugs, and makes the save/load reliable. It is hard to make the right judgement when there are so many frustrating things.