Would like to know if there is a limit to the number of threads, cores it can handle and if so how high it is.
Help greatly appreciated.
There is no real limit for threads on an operating system. There may be an operating system specific hard limit. For example on windows machines by default the thread stack reserve has a size of 1MB. That means each thread requires roughly 1MB of memory. That would give you a theoritical hard limit of 6000 threads on a machine with 6GB of memory. If you have time to read, read this post as an example.
However all this is pretty pointless. For actual load balancing a single process shouldn’t create more heavy load threads than there are cores in the CPU, otherwise two or more threads actually have to run on the same core so they don’t run in parallel but have to share time slices. This actually harms performance since task switches is overhead that could be avoided.