We discuss the parallelization of algorithms for solving polynomial systems symbolically by way of triangular decompositions. We introduce a component-level parallelism for which the number of processors in use depends on the geometry of the solution set of the input system. Our long term goal is to achieve an efficient multi-level parallelism: coarse grained (component) level for tasks computing geometric objects in the solution sets, and medium/fine grained level for polynomial arithmetic such as GCD/resultant computation within each task. Component-level parallelization of triangular decompositions belongs to the class of dynamic irregular parallel applications, which leads us to address the following question: How to exploit geometrical information at an early stage of the solving process that would be favorable to parallelization? We report on the effectiveness of the approaches that we have applied, including ”modular methods”, ”solving by decreasing order of dimension...