Revisions
| Revision | Processor Brand(s) | Pipeline stages |
|---|---|---|
| Willamette (180 nm) | Celeron, Pentium 4 | 20 |
| Northwood (130 nm) | Celeron, Pentium 4, Pentium 4 HT | 20 |
| Gallatin (130 nm) | Pentium 4 HT Extreme Edition, Xeon | 20 |
| Prescott (90 nm) | Celeron D, Pentium 4, Pentium 4 HT, Pentium 4 Extreme Edition | 31 |
| Cedar Mill (65 nm) | Celeron D, Pentium 4 | 31 |
| Smithfield (90 nm) | Pentium D | 31 |
| Presler (65 nm) | Pentium D | 31 |
Intel replaced the original Willamette core with a redesigned version of the NetBurst microarchitecture called Northwood in January 2002. The Northwood design combined an increased cache size, a smaller 130 nm fabrication process, and Hyper-Threading Technology (although initially all models but the 3.06 GHz model had this feature disabled) to produce a more modern, higher-performing version of the NetBurst microarchitecture.
In February 2004, Intel introduced another, more radical revision of the microarchitecture codenamed Prescott. The Prescott core was produced on a 90 nm process, and included several major design changes, including the addition of an even larger cache (from 512 KB in the Northwood to 1 MB, and 2 MB in Prescott 2M), a much deeper instruction pipeline (31 stages as compared to 20 in the Northwood), a heavily improved branch predictor, the introduction of the SSE3 instructions, and later, the implementation of Intel 64, Intel's branding for their compatible implementation of the x86-64 64-bit version of the x86 microarchitecture (as with hyper-threading, all Prescott chips branded Pentium 4 HT have hardware to support this feature, but it was initially only enabled on the high-end Xeon processors, before being officially introduced in processors with the Pentium trademark). Despite having many new features, the Prescott often performed worse than a similarly-clocked Northwood, and many engineers felt that the real-world performance of the processor was compromised by attempting to achieve the highest clock speed possible. Power consumption and heat dissipation also became major issues with Prescott, which quickly became the hottest-running, and most power-hungry, of Intel's single-core x86 and x86-64 processors. Power and heat concerns prevented Intel from releasing a Prescott clocked above 3.8 GHz, along with a mobile version of the core clocked above 3.46 GHz.
Intel also released a dual-core processor based on the NetBurst microarchitecture branded Pentium D. The first Pentium D core was codenamed Smithfield, which is actually two Prescott cores in a single die, and later Presler, which consists of two Cedar Mill cores on two separate dies (Cedar Mill being the 65 nm die-shrink of Prescott).
Read more about this topic: NetBurst (microarchitecture)
Famous quotes containing the word revisions:
“The lore of our fathers is a fabric of sentences. In our hands it develops and changes, through more or less arbitrary and deliberate revisions and additions of our own, more or less directly occasioned by the continuing stimulation of our sense organs. It is a pale gray lore, black with fact and white with convention. But I have found no substantial reasons for concluding that there are any quite black threads in it, or any white ones.”
—Willard Van Orman Quine (b. 1908)