Nehalem is the codename for Intel's 45 nm microarchitecture released in November 2008. It was used in the first generation of the Intel Core i5 and i7 processors, and is a major evolution over the older Core microarchitecture, which is used by Core 2 processors and is the previous iteration of the P6 microarchitecture series which started in 1995 with the Pentium Pro. The term "Nehalem" comes from the Nehalem River.

Nehalem is built on the 45 nm process, is able to run at higher clock speeds without sacrificing efficiency, and is more energy-efficient than Penryn microprocessors. Hyper-threading is reintroduced, along with a reduction in L2 cache size, as well as an enlarged L3 cache that is shared among all cores. Nehalem is an architecture that differs radically from NetBurst, while retaining some of the latter's minor features.

Nehalem later received a die-shrink to 32 nm with Westmere, and was fully succeeded by "second-generation" Sandy Bridge in January 2011.

Technology

The Nehalem microarchitecture evolved from the Core microarchitecture by introducing:

Cache line block on L2/L3 cache was reduced from 128 bytes in NetBurst & Merom/Penryn to 64 bytes per line in this generation (same size as Yonah and Pentium M). Hyper-threading technology again. Intel Turbo Boost 1.0. 2–24 MiB L3 cache with Smart Cache in some models. Instruction Fetch Unit (IFU) containing second-level branch predictor with two level Branch Target Buffer (BTB) and Return Stack Buffer (RSB). Nehalem also supports all predictor types previously used in Intel's processors like Indirect Predictor and Loop Detector. sTLB (second level unified translation lookaside buffer) (i.e. both instructions and data) that contains 512 entries for small pages only, and is again 4 way associative. 3 integer ALU, 2 vector ALU and 2 AGU per core. Native (all processor cores on a single die) quad-, hex-, and octa-core processors Intel QuickPath Interconnect in HEDT, server, and workstation models and Direct Media Interface on other models replacing the legacy front side bus. 64 KB L1 cache per core (32 KB L1 data and 32 KB L1 instruction), and 256 KB L2 cache per core. Integration of PCI Express and DMI into the processor in mid-range models, replacing the northbridge. Integrated memory controller supporting two or three memory channels of DDR3 SDRAM or four FB-DIMM2 channels. Second-generation Intel Virtualization Technology, which introduced Extended Page Table support, virtual processor identifiers (VPIDs), and non-maskable interrupt-window exiting. SSE4.2 and POPCNT instructions. Macro-op fusion now works in 64-bit mode. 20 to 24 pipeline stages.

{| class="wikitable" style="text-align: center" |+ Translation lookaside buffer sizes |- ! colspan=2 | Cache ! colspan=2 | Page Size |- ! Name || Level || 4 KB || 2 MB

| DTLB || 1st || 64 || 32

| ITLB || 1st || 128 || 7 / logical core

| STLB || 2nd || 512 || none

Performance and power improvements It has been reported that Nehalem has a focus on performance, thus the increased core size. Compared to Penryn, Nehalem has: 10–25% better single-threaded performance / 20–100% better multithreaded performance at the same power level 30% lower power consumption for the same performance On average, Nehalem provides a 15–20% clock-for-clock increase in performance per core.

Overclocking is possible with Bloomfield processors and the X58 chipset. Lynnfield processors use a PCH removing the need for a northbridge.

Nehalem processors incorporate SSE4.2 SIMD instructions, adding seven new instructions to the SSE 4.1 set in the Core 2 series. The Nehalem architecture reduces atomic operation latency by 50% in an attempt to eliminate overhead on atomic operations such as the LOCK CMPXCHG compare-and-swap instruction.

Variants Processing Cores (interface) Process Die Size million transistors CPUID Model Stepping Mobile Desktop, UP Server DP Server MP Server Eight-Core (Quad-Channel) 45 nm 684 mm2 2.300 206E6 46 D0 Beckton (80604) Quad-Core (Triple-Channel) 263 mm2 731 106A4106A5 26 C0/C1D0 Bloomfield (80601) Gainestown (80602) Quad-Core (Dual-Channel, PCIe) 296 mm2 774 106E4106E5 30 B0B1 Clarksfield (80607) Lynnfield (80605) Jasper Forest (80612) Dual-Core (Dual-Channel, PCIe, Graphics Core)? Auburndale (80608) (canceled) Havendale (80606) (canceled)

Lynnfield processors feature 16 PCIe lanes, which can be used in 1x16 or 2x8 configuration. 1 6500 series scalable up to 2 sockets, 7500 series scalable up to 4/8 sockets.

Server, workstation, and desktop processors

Codename Market Cores(threads) Socket ProcessorBranding & Model CPUClock rate Turbo TDP Interfaces L3cache Release date Price Chipset Memory Beckton1 MP Server /DP Server 8 (16) LGA1567 Xeon 7000 X7560 2.26 GHz rowspan=9 130 W 4× QPI 6.4 GT/s DDR3-800 /1066(Up to 4x withSMB-Readymotherboard) 24 MB 2010-03-30 $3692 X7550 2.0 GHz 18 MB $2837 X6550 $2461 L7555 1.86 GHz 95 W 4× QPI 5.86 GT/s 24 MB $3157 6 (12) E7540 2.0 GHz 105 W 4× QPI 6.4 GT/s 18 MB $1980 E6540 12 MB $1712 E7530 1.86 GHz 4× QPI 5.86 GT/s $1391 L7545 95 W 18 MB $2087 6 (6) X7542 2.66 GHz 130 W $1980 4 (8) E7520 1.86 GHz rowspan=2 105 W 4× QPI 4.8 GT/s $856 E6510 1.73 GHz 12 MB $744 Gainestown DP Server 4 (8) LGA1366 Xeon 5000 W5590 3.33 GHz rowspan=11 130 W 2× QPI 6.4 GT/s 3× DDR3-13331 8 MB 2009-08-09 $1600 W5580 3.2 GHz 2009-03-29 $1500 X5570 2.93 GHz 95 W $1286 X5560 2.8 GHz $1072 X5550 2.66 GHz $858 E5540 2.53 GHz 80 W 2× 5.86 GT/s 3× DDR3-10661 $744 E5530 2.4 GHz $530 E5520 2.26 GHz $373 L5530 2.4 GHz 60 W 2009-08-09 $744 L5520 2.26 GHz 2009-03-30 $530 L5518 2.13 GHz $ 4 (4) E5507 2.26 GHz rowspan=4 80 W 2× 4.8 GT/s 3× DDR3-8001 4 MB 2010-03-16$266 E5506 2.13 GHz 2009-03-29 L5506 2.13 GHz 60 W $423 E5504 2.0 GHz 80 W $224 2 (4) L5508 2.0 GHz 38 W 2× 5.86 GT/s 3× DDR3-1066 8 MB $ 2 (2) E5503 2.0 GHz rowspan=2 80 W 2× 4.8 GT/s 3× DDR3-800 4 MB 2010-03-16 $224 E5502 1.86 GHz 2009-03-29 $188 Jasper Forest 4 (8) EC5549 2.53 GHz rowspan=3 85 W 1× 5.86 GT/s 3× DDR3-1333 8 MB 2010-02-11 $530 LC5528 2.13 GHz 60 W 1× 4.8 GT/s 3× DDR3-1066 $519 LC5518 1.73 GHz 48 W 4 (4) EC5509 2 GHz rowspan=2 85 W $265 2 (4) EC5539 2.27 GHz 65 W 1× 5.86 GT/s 3× DDR3-1333 4 MB $387 Bloomfield UP Server 4 (8) Xeon 3000 W3580 3.33 GHz rowspan=7 130 W 1× QPI 6.4 GT/s 3× DDR3-1333 8 MB 2009-08-09 $999 W3570 3.2 GHz 2009-03-29 W3565 3.2 GHz 1× QPI 4.8 GT/s 3× DDR3-1066 2009-11-01$562 W3550 3.06 GHz 2009-08-09 W3540 2.93 GHz 2009-03-29 W3530 2.8 GHz 2010-03-16 $294 W3520 2.66 GHz 2009-03-29 $284 2 (2) W3505 2.53 GHz rowspan=3 4 MB $ W3503 2.4 GHz $ Jasper Forest 4 (4) EC3539 2.13 GHz 65 W DMI 8 MB 2010-02-11 $302 2 (4) LC3528 1.73 GHz 35 W 3× DDR3-800 4 MB 1 (1) LC3518 23 W 2 MB $192Lynnfield 4 (8)LGA1156 X3480 3.06 GHz rowspan=7 95 WDMI2× DDR3-1333 8 MB 2010-05-30 $612 X3470 2.93 GHz 2009-09-08 $589 X3460 2.8 GHz $316 X3450 2.66 GHz $241 X3440 2.53 GHz $215 L3426 1.86 GHz 45 W $284 4 (4) X3430 2.4 GHz 95 W $189 Bloomfield EnthusiastDesktop 4 (8) LGA1366 Core i7Extreme 975X 3.33 GHz rowspan=7 130 W 1× QPI 6.4 GT/s 3× DDR3-1066 2009-05-31 $999 965X 3.2 GHz 2008-11-17 Core i7 960 3.2 GHz 1× QPI 4.8 GT/s 2009-10-20 $562 950 3.06 GHz 2009-05-31 940 2.93 GHz 2008-11-17 930 2.8 GHz 2010-02-28 $294 920 2.66 GHz 2008-11-17 $284 Lynnfield PerformanceDesktop LGA1156 880 3.06 GHz rowspan=9 95 W DMI 2× DDR3-1333 2010-05-30 $583 875K 2.93 GHz $342 870 2009-09-08 $562 870S 2.66 GHz 82 W 2010-07-19 $351 860 2.8 GHz 95 W 2009-09-08 $284 860S 2.53 GHz 82 W 2010-01-07 $337 4 (4) Core i5 760 2.8 GHz 95 W 2010-07-17 $209 750 2.66 GHz 95 W 2009-09-08 $196 750S 2.4 GHz 82 W 2010-01-07 $259 Jasper Forest EmbeddedDesktop 1 (2) LGA1366 Celeron P1053 1.33 GHz 30 W 3× DDR3-800 2 MB 2010-12-02 $160 Intel states the Gainestown processors have six memory channels. Gainestown processors have dual QPI links and have a separate set of memory registers for each link in effect, a multiplexed six-channel system.

Mobile processors

Codename Market Cores /Threads Socket ProcessorBranding & Model CoreClock rate Turbo TDP L3cache Interface Release date PriceClarksfield Extreme mobile4 (8) Socket G1 rPGA 988 Core i7Extreme 940XM 2.13 GHz rowspan=6 55 W 8 MB* DMI* 2x DDR3-1333* PCIe 1 x16 / 2 x8 2010-06-21 $1096 920XM 2.0 GHz 2009-09-23 $1054Quad-core mobile Performance mobile Core i7 840QM 1.86 GHz 45 W 2010-06-21 $568 820QM 1.73 GHz 2009-09-23 $546 740QM 6 MB 2010-06-21 $378 720QM 1.6 GHz 2009-09-23 $364

See also List of Intel CPU microarchitectures Tick–tock model

References

Further reading

External links Nehalem processor at Intel.com