In this paper we provide both a qualitative and a quantitative evaluation of a decoupled multithreaded architecture that uses non-blocking threads. Our architecture is based on simple in-order pipelines and complete decoupling of memory accesses from execution pipelines. We extend the architecture to support thread level speculation using snooping cache coherency protocols. We evaluate the performance gains from speculations by varying the number of load/store instructions compared to computational instructions, miss speculation rates and the degree of thread level speculation. Our architecture presents a viable alternative to complex superscalar and super-speculative CPUs.