Westmere (microarchitecture)

Westmere (formerly Nehalem-C) is a CPU microarchitecture developed by Intel. It is a 32 nm die shrink of its predecessor, Nehalem, and shares the same CPU sockets with it. Some Westmere models have integrated graphics processors, branded as Intel HD Graphics, that support DirectX 10.1 and OpenGL 2.1 API.

The first Westmere-based processors were released on January 7, 2010. They were labeled under Intel's Core, Pentium, Celeron, and Xeon brandings.

Technology

Westmere's feature improvements from Nehalem, as reported, include:

Native six-core (Gulftown) and ten-core (Westmere-EX) processors.
AES-NI instruction set support:
Out of the total seven new instructions, six implement the AES algorithm specifically, the remaining PCLMULQDQ instruction (see CLMUL instruction set) accelerates carry-less multiplication for use in cryptography and data compression.
Integrated graphics, fabricated on a separate die using 45 nm process, and added onto the processor package, beside the CPU die, (for dual core Arrandale and Clarkdale only).
Improved virtualization latency and support for VMX Unrestricted mode, allowing 16-bit guests to run in real mode and big real mode.
Support for "Huge Pages" of 1 GB in size.

TDP includes the integrated GPU, if present.
Clarkdale processors feature 16 PCIe 2.0 lanes, which can be used in 1x16 or 2x8 configuration.
Clarkdale and Arrandale contain the 32 nm dual core processor Hillel and the 45 nm integrated graphics device Ironlake, and support switchable graphics.
Only certain higher-end CPUs support AES-NI and 1GB Huge Pages.

The successor to Nehalem and Westmere is Sandy Bridge.