HardwareReview: With the recent introduction of dual-core processors come more questions about system performance. Does a dual-core computer really perform better than a single-core CPU? How does it compare to a true multi-CPU system? What about Hyper-Threading Technology -- is it a thing of the past? Read on for an explanation of dual-core processors and symmetric multiprocessing and what it means to your computing experience.
Dual cores and multiple CPUs
CPUs with two processing cores are all the latest fashion today with Intel and AMD, but it's by no means a new idea -- IBM has had multi-core CPUs for a few years, and one of its most recent designs has 9 logic cores in a single processor. Dual core processors can perform the logic work of two discrete processors; the only downside is, the two cores must share the same resources (cache memory, RAM, and memory controller).
While the on-die cache memory on AMD and Intel dual-core processors is divided evenly between the two cores -- meaning the cache isn't shared globally -- that also means that there is less cache memory for each processor. The Athlon 64 X2 and the Intel Pentium D both have 2MB of cache memory, so each core gets 1MB.