Many computer systems are based on multiple processors, but not always in immediately obvious ways.

• Many of Intel's CPUs support a technology which they call hyper-threading, which is where the CPU is actually viewed by the system as two logical processors.
• Some of the most recent Intel/AMD CPUs actually consist of multiple physical processors inside a single package, these are known as dual core processors.
• Some high-end computer systems actually have multiple physical processors installed on specialised motherboards to provide a significant performance increase over a uniprocessor system. You'll probably know if you have such a system, since they aren't cheap.

In all of these cases, you need to select the appropriate kernel options to obtain optimum performance from these setups.

Processor type and features  --->
 [*] Symmetric multi-processing support
 Select the above option if you are on a multi-processor system (of any type)
 [*]   SMT (Hyperthreading) scheduler support
 Select the above option if you are on an Intel Hyper-Threading CPU
 [*]   Multi-core scheduler support (NEW)
 Select the above option if your CPU is dual core