"I couldn't comment on a specific game (I don't know much about how Dishonored performs), but the 5800X3D is definitely a big upgrade on the 2700. The problem is, going from
these charts, it looks like you're more likely to be GPU limited right now, since they show next to zero difference between Zen to Zen 3 with a 5700 XT in the majority of games at 1440p.
You could get an upgrade on the 5700 XT, but then, CPU/GPU scaling charts like these (
0,
1,
2) suggest there's a ceiling around a 6800 XT, beyond which your CPU is going to be bottlenecking the card.
0. This shows that using a 4090 with a 2600X nearly doubles the FPS at 1440p from a 1080 Ti, but a 5600X nearly doubles the FPS again on the 2600X, suggesting that the 4090 is only achieving half (or less, as even the 5600X bottlenecks it) of what it is capable of.
1. These charts are at 1080p, but even with a CPU that is faster than the 2700 in games (i3-13100), not many games show an improvement between the RX 6950 XT and 4090. Though, there is a decent improvement from the 6650 XT to the 6950 XT (this is part of how I guesstimate a 6800 XT to be the ceiling).
If you only have the budget for the X3D, I'm not sure you're going to find it all that useful, but it would give you the headroom for the GPU upgrade."