The
Pentium D brand refers to two series of desktop
dual-core 64-bit x86-64 microprocessors with the
NetBurst microarchitecture, which is the dual-core variant of
Pentium 4 "Prescott" manufactured by
Intel. Each
CPU comprised two
dies, each containing a single core, residing next to each other on a
multi-chip module package. The brand's first processor, codenamed
Smithfield, was released by
Intel on May 25, 2005. Nine months later, Intel introduced its successor, codenamed
Presler, but without offering significant upgrades in design, still resulting in relatively high power consumption. By 2004, the NetBurst processors reached a
clock speed barrier at 3.8 GHz due to a thermal (and power) limit exemplified by the
Presler's 130
watt thermal design power (a higher TDP requires additional cooling that can be prohibitively noisy or expensive). The future belonged to more energy efficient and slower clocked
dual-core CPUs on a single
die instead of two. The final shipment date of the dual die
Presler chips was August 8, 2008, which marked the end of the Pentium D brand and also the NetBurst microarchitecture.