Front Side Bus
The Front Side Bus (FSB) is the connecting path between the CPU and other key components such as system memory.
The Front Side Bus is also called the Data Bus and the Processor Side Bus (PSB).
Front Side Bus Widths of Various CPUs
| CPU | Front Side Bus Width |
|---|---|
| 8088 | 8 |
| 8086 | 16 |
| 80286 | 16 |
| 80386SX | 16 |
| 80386DX | 32 |
| 80486 | 32 |
| AMD 5×86 | 32 |
| Pentium | 64 |
| AMD K6 | 64 |
| Pentium Pro | 64 |
| Celeron | 64 |
| Pentium II | 64 |
| Pentium III | 64 |
| AMD Duron | 64 |
| AMD Athlon | 64 |
| AMD Athlon XP | 64 |
| Pentium 4 | 64 |
| Itanium | 64 |
| AMD Athlon 64 | 64 |
Competing Front Side Bus Technologies
The EV6 Front Side Bus

AMD uses the EV6 Front Side Bus in its Athlon and Athlon XP CPUs.
Athlon and Athlon XP CPUs with the EV6 bus are able to transfer data over the Front Side Bus twice per processor cycle.
The AGTL+ Front Side Bus
Intel uses the AGTL+ Front Side Bus in its Pentium 4 processors.
Pentium 4s with AGTL+ are able to transfer data over the Front Side Bus four times per processor cycle.
However, the AGTL+ bus is shared among all of the systems CPUs. The EV6 bus is a point-to-point bus, meaning that the full bandwidth of the bus is available to every CPU.
HyperTransport
AMD Athlon64, AthlonFX, and Opteron CPUs utilize the HyperTransport Bus.
These CPUs move the memory controller into the CPU, effectively eliminating the Front Side Bus.
- Athlon-64
Athlon-64 is a name for AMD’s main line of 64-bit CPUs. The Athlon-64 line is designed to complete against the Intel Pentium CPUs. Athlon-64 processors are designed to execute 32-bit and 64-bit instructions simultaneously. This enables them to directly address more than 4GB of RAM. Athlon-64 CPUs feature an L1 cache with 64KB of RAM [...]...
- Xeon
Xeon is an marketing name for Intel’s server-class CPUs from the Pentium family. Intel has manufactured and sold Xeon versions of the Pentium II, Pentium III, Pentium 4, and Pentium MP CPUs. Xeon CPUs are differentiated from each other by their CPU speeds, Front Side Bus speeds, and the size of their L2 cache and [...]...
- Dual Core
A dual core processor is part of a category called multi-core processors. These computer processors have more than one independent processor on the chip or package. In the case of a dual core processor, the entire chip has two independent computer processors that can work together to increase total computer performance. For non-technical consumers, dual [...]...
- EM64T (Intel 64)
EM64T (Extended Memory 64 Technology), now known more commonly as Intel 64 or the x64 (that is when including AMD64 too), is a 64 bit superset/extensions that central processing units (CPUs) process. It is widely used in Intel’s processors, including Pentium 4, Pentium D, Pentium Extreme Edition, Celeron D, Xeon, Pentium Dual Core, and Core [...]...
- How to Overclock a CPU
Overclocking is the process making a computer component run at a higher speed than that specified by the manufacturer. The components that can be overclocked include the CPU, the memory and the video cards. Although there may be many different reasons for overclocking, the most common reason is to increase hardware performance. For example the [...]...




