Dual Core Processor

The transition from a single core to dual core architecturewas triggered by a couple of factors. According to Moore's Law, the number of transistors (complexity) on a microprocessor doubles approximately every 18 months. The latest 2 MB Prescott core possesses more than 160 million transistors; breaking the 200million mark is just a matter of time. Transistor count is one of the reasons that drive the industry toward thedual core architecture. Instead of using the availableastronomically high transistorcounts to design a new, morecomplex single core processor that would offer higher performance than the present offerings, chip makers have decided to put these transistors to use in producing two identical yet independent cores and combining them in to a single package. To them, this is actually a farbetter use of the available transistors, and in return should give the consumers more value for their money. Besides, with the single core's thermal envelope being pushed to its limit and severe current leakage issues that have hit the silicon manufacturing industryever since the transition to 90 nm chip fabrication, it's extremely difficult for chip makers (particulary Intel) to squeeze more clock speed out of the present single core design. Pushing for higher clock speeds is not a feasible option at present because of transistor currentleakage. And adding more features into the core will increase the complexity of the design and make it harder to manage. These arethe factors that have made the dual core option the moreviable alternative in making full use of the amount of transistors available. What is a dual core processor? A dual core processor is a CPU with two separate cores on the same die, each with itsown cache. It's the equivalentof getting two microprocessors in one. In a single-core or traditional processor the CPU is fed strings of instructions it mustorder, execute, then selectively store in its cache for quick retrieval. When data outside the cache is required, it is retrieved through the system bus from random access memory (RAM)or from storage devices. Accessing these slows down performance to the maximum speed the bus, RAM or storage device will allow, which is far slower than the speed of the CPU. The situation is compounded whenmulti-tasking. In this case theprocessor must switch back and forth between two or more sets of data streams and programs. CPU resourcesare depleted and performance suffers. In a dual core processor each core handles incoming data strings simultaneously to improve efficiency. Just astwo heads are better than one, so are two hands. Now when one is executing the other can be accessing the system bus or executing its own code. Adding to this favorable scenario, both AMDand Intel's dual-core flagships are 64-bit. To utilize a dual core processor, the operating system must be able to recognize multi-threading and the software must have simultaneous multi-threadi0ng technology (SMT) written into its code. SMT enables parallel multi-threading wherein the cores are served multi-threaded instructions in parallel. Without SMT the software willonly recognize one core. Adobe Photoshop is an example of SMT-aware software. SMT is also used with multi-processor systemscommon to servers. An attractive value of dual core processors is that they do not require a new motherboard, but can be used in existing boards that feature the correct socket. For the average user the difference in performance willbe most noticeable in multi-tasking until more software isSMT aware. Servers running multiple dual core processorswill see an appreciable increase in performance.