Simple answer: All the hardware in the world can't fix slow code that hasn't been tailored to benefit from parallel processing using multiple cores or GPU. That's really all there is to it. Most Adobe programes are simply lousy at multithreaded processing and the like due to carrying around lots of legacy bagagge how some features came to be and PS is no exception. In essence about 70% or so of all functions chug along using linear processing on a single core one way or the other and even if accelerated functions are used, others may still break the potential speedups. That's pretty much the deal - PS would just love to have an infinitely fast single-core GPU to run its algorithms, but can't take advantage of contemporary stuff that much beyond certain functions liek file I/O that scale with native hardware speeds.
thanks mate! However, not even one single core is being used to its full potential. So even if it would use only one care, it could use all of it...And why doesn't it use the graphics card if I turned on this feature in the settings
So basically what you're saying, Mylenium, is forget it, Photoshop has always and will always run like a dog? That's obviously not the case, as I can confirm myself. Photoshop is one of the snappiest programs I have. Photoshop is well optimized - and multithreaded - for quad core CPUs, however, more than six cores yields diminishing returns.
First of all, disable all third-party plugins, font managers, extensions of all kinds.
Turn off GPU in ACR preferences. Unless you have a 4K / 5K display, it just adds overhead and slows everything down. It's not needed for standard displays and will not do anything.
Also try to turn it off in Photoshop. It does nothing for general application speed, it just enables some additional functions. But a buggy driver can bog a system down. If that helps, try enabling it again with the "basic/normal/advanced" options respectively.
Reset Photoshop preferences. Just tick it in the Preferences dialog and relaunch.