Intel Hyperthread Technology vs. Dual Core

A dual core computer has extra hardware to make it faster: two processors, each called a core. Hyperthreading is a software solution for using processor resources more efficiently. If you're comparing Intel models to replace a Web server or employee workstation, remember that a dual core computer will always be faster than a single core computer, even with hyperthreading.

When you purchase a dual core computer, you're buying a computer with two CPUs on the same chip. Each CPU operates independently and has its own cache to store values. However, the two CPUs share the bus that reads and writes data to and from memory. While the first CPU processes information, the second CPU uses the bus to retrieve instructions and data from memory. The second CPU then processes its information while the first CPU sends results and retrieves new instructions.

A thread is a process that runs on a CPU. CPUs can only execute a single thread at a time. However, a single thread doesn't typically use all of the processor's resources. To make better use of the CPU's resources, hyperthreading divides the processor's resources to create two virtual processors from a single physical processor. To the operating system, it appears as though there are two processors that can each run a simultaneous thread. The result should be improved performance over a computer without hyperthreading.

A dual core computer uses hardware to increase performance. It has two physical processors that effectively double the performance compared to a computer with a single processor. Hyperthreading doesn't add any hardware to the computer. It is a virtual solution that can increase performance through more efficient use of a processor's resources. To maximize performance, combine both solutions and use a dual core computer that supports hyperthreading. The two physical cores are dividied into four virtual cores to improve performance.

With hyperthreading, a single process takes longer to complete, but you can run more of them. The performance gains with hyperthreading depend on the type of processing the CPUs perform. Hyperthreading tends to work better with multicore CPUs because both CPUs are not always active at the same time. If a single process consumes the majority of CPU time, or if processes depend on a substantial amount of disk input and output, you should disable hyperthreading because it could lower performance.