Difference Between Sandy Bridge and Nehalem Architecture

Sandy Bridge vs Nehalem Architecture

Sandy Bridge and Nehalem Architectures are two of the most recent processor microarchitectures introduced by Intel. Nehalem processor architecture was released in 2008 and was the successor to Core microarchitecture. Sandy Bridge processor microarchitecture was the successor to the Nehalem microarchitecture and it was released in 2011. Obviously, being the later release, Sandy Bridge possesses improvement over the features and performance offered by Nehalem architecture.

Nehalem Architecture

Nehalem processor architecture was released in 2008 and was the successor to Core microarchitecture. 45 nm manufacturing methods were used for Nehalem architecture. In November 2008 Intel released their first processor designed using the Nehalem processor microarchitecture and it was the Core i7. Few other Xeon processors, i3 and i7 soon followed. Apple Mac Pro workstation was the first computer that included the Xeon processor (based on Nehalem). In September 2009, the first Nehalem architecture based mobile processer was released. Nehalem processor architecture reintroduced hyperthreading and a L3 cache (up to 12MB, shared by all cores), which were missing in Core-based processors. Nehalem processor came in 2, 4 or 8 cores. Other notable features present in Nehalem microprocessors are DDR3 SDRAM or DIMM2 memory controller, Integrated Graphics Processor (IGP), PCI and DMI integration to the processor, 64 KB L1, 256 KB L2 caches, second level branch prediction and translation lookaside buffer.

Sandy Bridge Architecture

Sandy Bridge processor architecture is the successor to Nehalem architecture mentioned above. Sandy Bridge is based on 32 nm manufacturing methods. First processor based on this architecture was released on January 9, 2011. Similar to Nehalem, Sandy Bridge uses 64KB L1 cache, 256 L2 cache and a shared L3 cache. Improvements over Nehalem are its optimized branch prediction, facilitation for transcendental mathematics, encryption support via AES with and SHA-1 hashing. Furthermore, an instruction set supporting 256-bit wider vectors for floating-point arithmetic called Advanced Vector Extensions (AVX) is introduced in Sandy Bridge processors. It has been found that Sandy Bridge processors provides up to 17% increased CPU performance compared to Lynnfield processors based on Nehalem architecture.

Difference between Sandy Bridge and Nehalem Architecture

Sandy Bridge architecture released in 2011 is the successor to the Nehalem processor microarchitecture, which was released in 2008. Understandably, Processors based on Sandy Bridge architecture has a number of improvements over processors based on Nehalem Architecture. A notable difference in specifications is that Sandy Bridge uses a smaller nm technology for its circuitry. Performance wise, it is claimed that there is a 17% improvement in terms of per-clock basis in Sandy Bridge processors than Nehalem processors. Sandy Bridge has improved branch prediction, transcendental mathematics facilities, AES for encryption, SHA-1 for hashing and Advanced Vector Extension for improved floating-point arithmetic. In a benchmark study conducted by SiSoftware between a 3066MHz, 4 core Nehalem processor and a 3000MHz, 4 core Sandy Bridge processor, it was found that the latter outperforms the former in the areas of CPU arithmetic, CPU multimedia, Multi-core efficiency, Cryptography and power efficiency. Furthermore, in the areas of Media transcoding, Memory controller speed and L3 cache performance, the Sandy Bridge processor wins the battle over Nehalem processor.