Why aren't all programming problems solved with parallel programming?

Not all problems can be solved using a parallel algorithm, and not all hardware is capable of running multiple threads concurrently.

• Not all systems have parallel execution engines. Only in the last few decades have machines sported GPUs with massively-parallel computation pipelines. And in even less time have all computers come equipped with multicore processors. Even today, memory or network bandwidth may preclude parallel computation.

It is not possible to solve all the programming problems parallely because some of them didnt support the parallel operation

Not all problems are parallelizable. For example, ray tracing—rendering a 3D scene—is easily parallelizable: Each rendered pixel represents a separate compute operation that may be executed independently. But not all problems are like ray tracing; many are I/O bound. And even some compute-bound problems, such as the algorithms behind many cryptographic operations, are inherently serial. Such problems cannot be converted into parallel operations and thus are unsolvable using parallel programming.

First of all simple not all problems are so straightforward that they could be easily parallelizable.

For such kind of problems, we may have to put much great effort than the intended cost.

One more important thing regarding is that to apply this technique to any problem one must have sound knowledge of the domain as well as the problem. Because to perform this you must know which sections of the program should be parallelized and most importantly how and when.

 Becase java language is not solving all problems & there is alot of new language have alot of library