| Model Number | Frequency | L2-Cache | Front Side Bus | Multiplier | Voltage | TDP | Socket | Release Date | Part Number(s) |
|---|---|---|---|---|---|---|---|---|---|
| Pentium 4 HT 2.4C | 2400 MHz | 512 KiB | 800 MT/s | 12x | 1.475/1.525 V | 66.2 W | Socket 478 | May 21, 2003 | RK80532PG056512 |
| Pentium 4 HT 2.6C | 2600 MHz | 512 KiB | 800 MT/s | 13x | 1.475/1.525 V | 69 W | Socket 478 | May 21, 2003 | RK80532PG064512 |
| Pentium 4 HT 2.8C | 2800 MHz | 512 KiB | 800 MT/s | 14x | 1.475/1.525 V | 69.7 W | Socket 478 | May 21, 2003 | RK80532PG072512 |
| Pentium 4 HT 3.0 | 3000 MHz | 512 KiB | 800 MT/s | 15x | 1.475/1.55 V | 81.9 W | Socket 478 | April 14, 2003 | RK80532PG080512 |
| Pentium 4 HT 3.06 | 3066 MHz | 512 KiB | 533 MT/s | 23x | 1.475/1.55 V | 81.8 W | Socket 478 | November 14, 2002 | RK80532PE083512 |
| Pentium 4 HT 3.2 | 3200 MHz | 512 KiB | 800 MT/s | 16x | 1.475/1.55 V | 82 W | Socket 478 | June 23, 2003 | RK80532PG088512 |
| Pentium 4 HT 3.4 | 3400 MHz | 512 KiB | 800 MT/s | 17x | 1.475/1.55 V | 89 W | Socket 478 | February 1, 2004 | RK80532PG096512 |
| Model Number | Frequency | L2-Cache | Front Side Bus | Multiplier | Voltage | TDP | Socket | Release Date | Part Number(s) |
|---|---|---|---|---|---|---|---|---|---|
| Pentium 4 HT 2.8E | 2800 MHz | 1024 KiB | 800 MT/s | 14x | 1.25/1.4 V | 89 W | Socket 478 | February 1, 2004 | RK80546PG0721M |
| Pentium 4 HT 3.0E | 3000 MHz | 1024 KiB | 800 MT/s | 15x | 1.25/1.4 V | 89 W | Socket 478 | February 1, 2004 | RK80546PG0801M |
| Pentium 4 HT 3.2E | 3200 MHz | 1024 KiB | 800 MT/s | 16x | 1.25/1.4 V | 89/103 W | Socket 478 | February 1, 2004 | RK80546PG0881M |
| Pentium 4 HT 3.2F | 3200 MHz | 1024 KiB | 800 MT/s | 16x | 1.25/1.4 V | 84 W | LGA 775 | August 2004 | |
| Pentium 4 HT 3.4E | 3400 MHz | 1024 KiB | 800 MT/s | 17x | 1.25/1.4 V | 89/103 W | Socket 478 | February 1, 2004 | RK80546PG0961M |
| Pentium 4 HT 3.4F | 3400 MHz | 1024 KiB | 800 MT/s | 17x | 1.25/1.4 V | 115 W | LGA 775 | August 2004 | |
| Pentium 4 HT 3.6F | 3600 MHz | 1024 KiB | 800 MT/s | 18x | 1.25/1.4 V | 115 W | LGA 775 | August 4, 2004 | |
| Pentium 4 HT 3.8F | 3800 MHz | 1024 KiB | 800 MT/s | 19x | 1.25/1.4 V | 115 W | LGA 775 | November 2004 | |
| Pentium 4 HT 517 | 2933 MHz | 1024 KiB | 533 MT/s | 22x | 1.25/1.4 V | 84 W | LGA 775 | September 2005 | HH80547PE0771MM |
| Pentium 4 HT 520 | 2800 MHz | 1024 KiB | 800 MT/s | 14x | 1.25/1.4 V | 84 W | LGA 775 | June 2004 | JM80547PG0721M |
| Pentium 4 HT 520J | 2800 MHz | 1024 KiB | 800 MT/s | 14x | 1.25/1.4 V | 84 W | LGA 775 | October 2004 | JM80547PG0721M |
| Pentium 4 HT 521 | 2800 MHz | 1024 KiB | 800 MT/s | 14x | 1.25/1.4 V | 84 W | LGA 775 | June 12, 2005 | JM80547PG0721MM HH80547PG0721MM |
| Pentium 4 HT 524 | 3066 MHz | 1024 KiB | 533 MT/s | 23x | LGA 775 | HH80547PE0831MM | |||
| Pentium 4 HT 530 | 3000 MHz | 1024 KiB | 800 MT/s | 15x | 1.25/1.4 V | 84 W | LGA 775 | June 2004 | JM80547PG0801M |
| Pentium 4 HT 530J | 3000 MHz | 1024 KiB | 800 MT/s | 15x | 1.25/1.4 V | 84 W | LGA 775 | October 2004 | JM80547PG0801M |
| Pentium 4 HT 531 | 3000 MHz | 1024 KiB | 800 MT/s | 15x | 1.25/1.4 V | 84 W | LGA 775 | June 12, 2005 | JM80547PG0801M HH80547PG0801M |
| Pentium 4 HT 540 | 3200 MHz | 1024 KiB | 800 MT/s | 16x | 1.25/1.4 V | 84 W | LGA 775 | June 21, 2004 | JM80547PG0881M |
| Pentium 4 HT 540J | 3200 MHz | 1024 KiB | 800 MT/s | 16x | 1.25/1.4 V | 84 W | LGA 775 | October 2004 | JM80547PG0881M |
| Pentium 4 HT 541 | 3200 MHz | 1024 KiB | 800 MT/s | 16x | 1.25/1.4 V | 84 W | LGA 775 | June 12, 2005 | JM80547PG0881MM HH80547PG0881MM |
| Pentium 4 HT 550 | 3400 MHz | 1024 KiB | 800 MT/s | 17x | 1.25/1.4 V | 84 W | LGA 775 | June 21, 2004 | JM80547PG0961M |
| Pentium 4 HT 550J | 3400 MHz | 1024 KiB | 800 MT/s | 17x | 1.25/1.4 V | 84 W | LGA 775 | October 2004 | JM80547PG0961M |
| Pentium 4 HT 551 | 3400 MHz | 1024 KiB | 800 MT/s | 17x | 1.25/1.4 V | 84 W | LGA 775 | June 12, 2005 | JM80547PG0961MM HH80547PG0961MM |
| Pentium 4 HT 560 | 3600 MHz | 1024 KiB | 800 MT/s | 18x | 1.25/1.4 V | 115 W | LGA 775 | June 21, 2004 | JM80547PG1041M |
| Pentium 4 HT 560J | 3600 MHz | 1024 KiB | 800 MT/s | 18x | 1.25/1.4 V | 115 W | LGA 775 | October 2004 | JM80547PG1041M |
| Pentium 4 HT 561 | 3600 MHz | 1024 KiB | 800 MT/s | 18x | 1.25/1.4 V | 115 W | LGA 775 | June 12, 2005 | JM80547PG1041MM |
| Pentium 4 HT 570J | 3800 MHz | 1024 KiB | 800 MT/s | 19x | 1.25/1.4 V | 115 W | LGA 775 | November 12, 2004 | JM80547PG1121M |
| Pentium 4 HT 571 | 3800 MHz | 1024 KiB | 800 MT/s | 19x | 1.25/1.4 V | 115 W | LGA 775 | June 12, 2005 | JM80547PG1121MM |
| Model Number | Frequency | L2-Cache | Front Side Bus | Multiplier | Voltage | TDP | Socket | Release Date | Part Number(s) |
|---|---|---|---|---|---|---|---|---|---|
| Pentium 4 HT 620 | 2800 MHz | 2048 KiB | 800 MT/s | 14x | 1.2/1.4 V | 84 W | LGA 775 | JM80547PH1072MM | |
| Pentium 4 HT 630 | 3000 MHz | 2048 KiB | 800 MT/s | 15x | 1.2/1.4 V | 84 W | LGA 775 | February 20, 2005 | JM80547PG0802M |
| Pentium 4 HT 640 | 3200 MHz | 2048 KiB | 800 MT/s | 16x | 1.2/1.4 V | 84 W | LGA 775 | February 20, 2005 | JM80547PG0882M |
| Pentium 4 HT 650 | 3400 MHz | 2048 KiB | 800 MT/s | 17x | 1.2/1.4 V | 84 W | LGA 775 | February 20, 2005 | JM80547PG0962M |
| Pentium 4 HT 660 | 3600 MHz | 2048 KiB | 800 MT/s | 18x | 1.2/1.4 V | 115 W | LGA 775 | February 20, 2005 | JM80547PG1042M |
| Pentium 4 HT 662 | 3600 MHz | 2048 KiB | 800 MT/s | 18x | 1.2/1.4 V | 115 W | LGA 775 | November 14, 2005 | HH80547PG1042MH |
| Pentium 4 HT 670 | 3800 MHz | 2048 KiB | 800 MT/s | 19x | 1.2/1.4 V | 115 W | LGA 775 | May 26, 2005 | JM80547PG1122M |
| Pentium 4 HT 672 | 3800 MHz | 2048 KiB | 800 MT/s | 19x | 1.2/1.4 V | 115 W | LGA 775 | November 14, 2005 | HH80547PG1122MH |
| Model Number | Frequency | L2-Cache | Front Side Bus | Multiplier | Voltage | TDP | Socket | Release Date | Part Number(s) |
|---|---|---|---|---|---|---|---|---|---|
| Pentium 4 HT 631 | 3000 MHz | 2048 KiB | 800 MT/s | 15x | 1.2/1.4 V | 86 W | LGA 775 | January 16, 2006 | HH80552PG0802M |
| Pentium 4 HT 641 | 3200 MHz | 2048 KiB | 800 MT/s | 16x | 1.2/1.4 V | 86 W | LGA 775 | January 16, 2006 | HH80552PG0882M |
| Pentium 4 HT 651 | 3400 MHz | 2048 KiB | 800 MT/s | 17x | 1.2/1.4 V | 86 W | LGA 775 | January 16, 2006 | HH80552PG0962M |
| Pentium 4 HT 661 | 3600 MHz | 2048 KiB | 800 MT/s | 18x | 1.2/1.4 V | 86 W | LGA 775 | January 16, 2006 | HH80552PG1042M |
Hyper-threading, officially called Hyper-Threading Technology (HTT), is Intel's trademark for their implementation of the simultaneous multithreading technology on the Pentium 4 microarchitecture. It is a more advanced form of Super-threading that debuted on the Intel Xeon processors and was later added to Pentium 4 processors. The technology improves processor performance under certain workloads by providing useful work for execution units that would otherwise be idle, for example during a cache miss. A Pentium 4 with Hyper-Threading enabled is treated by the operating system as two processors instead of one.
The advantages of Hyper-Threading are listed as: improved support for multi-threaded code, allowing multiple threads to run simultaneously, improved reaction and response time, and increased number of users a server can support.
According to Intel, the first implementation only used an additional 5% of the die area over the "normal" processor, yet yielded performance improvements of 15–30%.
Intel claims up to a 30% speed improvement compared against an otherwise identical, non-SMT Pentium 4. The performance improvement seen is very application-dependent, however, and some programs actually slow down slightly when Hyper Threading Technology is turned on. This is due to the replay system of the Pentium 4 tying up valuable execution resources, thereby starving the other thread. However, any performance degradation is unique to the Pentium 4 (due to various architectural nuances), and is not characteristic of simultaneous multithreading in general.