One of the biggest problems with Path of Exile has been the performance issues in the game client. It's not strange that the game used to have desync problems, but it isn’t the most optimized game in the world. The game stutters when too much stuff comes up on screen, which is usually a really tough fight.
It's a legitimate concern for most players, especially for those playing in hardcore leagues wherein a little lapse can result in distressing. Even though you do everything right-get the build right, have all Path of Exile Items you need, and be strong enough in level to handle all those enemies with your PoE Currency, a short period of lag or stutter can result in all null and void, or at least unbelievable annoying. Exalted orb sometimes makes you play easily.
For the most part with the elimination of desync, network performance is something that has been tackled, although it can still be done in the front. As big strides have been taken when multithreading introduced by the content update for game client performance, making the client use more than one CPU core.
When multi-core CPUs are commonplace, it sounds ridiculous to let a game run only on a single core, but it's fairly common for various online games, especially free-to-play-to be mostly single-core applications since they develop way and have lower system requirements to accommodate an array of machines.
The problem is that when the game starts to have more things going on, like visual effects and other CPU intensive processes, it can impact performance greatly as single core works on overdrive to do all work while the other cores can't jump in to help. This means the game client is bottlenecking its own performance without having multithreading support.
When a single CPU core is inundated by a workload, it is suited for a machine with multiple CPU cores, not only the performance but also puts quite a strain on the CPU due to excess heat. That will make CPU throttle, which slows it down to keep it from hot. It doesn't help certain maps in the game tend to have a ton of visual effects and other things going on.
It gets better and better as a command line option has been added to let players choose to turn on frame multithreading, which allows the client to use more CPU cores for gameplay. It's granted that this feature is permanent instead of just an option, in order to make sure that there won't be game-crashing bugs associated with the functionality, Grinding Gear Games will have to test things out.
To improve graphics performance is the next step, which is something that could have been used for a long time. Grinding Gear Games has been working on D3D11 support, which isn't developed due to lower-end machines. For more interesting PoE news, you can feel free to visit MmoGah.com. Thanks.