What Is the Difference Between Hyper Threading & Multi-Core Technology

Hyper-threading and multi-core central processing unit technologies both improve system performance by increasing the amount of work the device can do in the same relative amount of time. However, hyper-threading and multi-core technologies approach performance gains differently, and both can be used simultaneously. Hyper-threading optimizes processes to improve CPU efficiency, while multi-core technology adds the equivalent to multiple processors in a single chip. Hyper-threading is a proprietary Intel technology, whereas any CPU maker can implement multiple-cores.



Threads and Processes




A single-core CPU doesn't actually multitask: rather, it's so fast at switching between tasks or threads that it gives the user the the impression and experience of running multiple programs at the same time. The processor divides how much of its time will be dedicated to each process in a given interval, and swaps between tasks rapidly to create the multi-tasking user environment. For example, if you're running Windows Media Player and editing an image in Adobe Photoshop, the CPU may be dividing its resources so that 10 percent goes to WMP, 30 percent goes to Adobe Photoshop, 20 percent goes to Windows, 10 percent goes to various other tasks and the remaining 30 percent is left unused.
Multi-core




Adding a second core to a CPU adds what the computer hypothetically doubles as processing power: a second core is like running two single-core processors. If the computer has multiple processors or a multi-core processor, it can actually run multiple tasks simultaneously. Multi-core CPUs can still only handle individual threads as fast as each CPU's clock-speed allows. However, programs can be written to split up tasks over multiple threads to take advantage of the multi-core technology. A computer that's running a dozen tasks at once can decrease how often it jumps between threads for each CPU in a multi-core environment.
Hyperthreading




Hyper-threading creates the effect of adding an additional core to an existing CPU, allowing it to more efficiently handle thread switching. The CPU is the fastest part of the computer, and it can only process information as fast as the rest of the computer can bring it over — this leads to inefficiencies when switching between tasks. If there's no information for the CPU to process, no work can be completed and the missed cycles are left unused. Hyper-threading helps organize multiple threads more efficiently so they can be passed to the CPU to process in the previously unused cycles. According to PC Stats, a CPU without hyper-threading typically runs at about 60 percent efficiency, whereas the use of this technology improves the efficiency to around 90 percent.
Drawbacks




Hyper-threading and multi-core technology improves general computer performance and multitasking capabilities in almost every situation. According to PC Magazine, hyper-threading may hinder individual thread performance, so users may see a performance improvement without hyper-threading when running just one thread at a time. Software needs to be written to take advantage of multiple threads to see performance boosts. Single-thread programs are unable to take advantage of multi-core and hyper-threading processors.