Pentium D

Pentium D is a series of microprocessors introduced by Intel during the Spring 2005 Intel Developer Forum. It consists of 2 Pentium 4 Prescott processors on a single die.

This was the first announced multicore CPU from any manufacturer for desktop computers. Intel underscored the significance of this introduction by predicting that at the end of 2006, over 70% of its desktop CPUs will be multicore. Analysts have predicted that the clock rate race between Intel and AMD is largely over, with no more exciting doubling of the clock rate every couple of years. Rather, as long as Moore's Law keeps holding up, it is expected that the additional transistors that chip companies can cram onto a CPU will be used to increase CPU throughput in other ways, such as by adding cores, as the Pentium D does.

The inital release of the Pentium D (codenamed "Smithfield") was on May 26 2005, with clock speeds of 2.8, 3.0, and 3.2 GHz. Smithfield is made on a 90 nm process with 1 MB of L2 cache per core. The Pentium D does not support Hyper-threading, at least initally, although similar Pentium XE counterparts will. The Pentium D will also implement true x86 virtualization, and numerous Virtual Machines, such as VMWare, will no longer have the mild overhead incurred by trapping protected mode calls. In Q1 2006, another Pentium D core (codenamed Presler) will be released. Presler will be made on a 65 nm process with 2 MB of L2 cache per core.

As with a multiprocessor PC, the Pentium D provides significant performance improvement only with applications that have been written specifically for multiple CPUs or cores — such as most 3D rendering programs and video encoders — and in heavy multitasking situations, where the PC user is running several CPU-heavy applications, and each core can handle a different application. Most business applications and games as of 2005 only use a single thread, so for these applications running alone, the Pentium D will deliver the same performance as an older Pentium 4 running at the same clock rate.

After a week of confusion following the processor's launch, Intel officially denied a report in Computerworld Today Australia that the Pentium D includes "secret" digital rights management features in hardware that could be utilized by Microsoft Windows and other operating systems, but was not publicly disclosed.

The Pentium D processor supports Intel's EM64T5 technology, and runs on a Smithfield core, with a front side bus speed of 800 megahertz, same as the most of the non-extreme edition, hyper-threading enabled Pentium 4s today. Using the new LGA775 interface, the CPU can run motherboards with Intel 945P, 945G, and 955X chipsets, or the more recent nVidia nForce 4 SLI Intel Edition chipsets. Currently the stock clock frequency limit is 3.2ghz, due to heat problems, and the fact that one heatsink must cool two cores. Pentium D 820 boasts two 2.8 gigahertz cores, the 830 3.0ghz cores, and 840 3.2ghz cores.

There are currently two version of the Pentium D, the regular edition (820, 830, 840) and the Extreme Edition (840EE). The difference in the Extreme Edition is that it, like modern-day Pentium 4HTs, uses hyper-threading (two virtual processors in one core). This essentially mean that there are four processors in one, and if so, the Windows Task Manager, four different processors available for use. The Pentium D also boasts a fully unlocked multiplier, making much more easier to overclock.

The reason for the high price of the Pentium D series is that thecores are manufactured together, which mean that should one fail, both must be disposed. However, as stated above, Intel has announced the Presler, which will have two cores manufactured separately and assembled into a single CPU, effectively reducing the cost.

--68.98.158.223 02:58, 16 Jun 2005 (UTC) Danny Kim