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Nehalem

Logo for Core i7 Bloomfield processors
General information
Launched	November 11, 2008; 16 years ago (November 11, 2008)
Marketed by	Intel
Designed by	Intel
Common manufacturer	Intel
Performance
Max. CPU clock rate	1.06 GHz to 3.33 GHz
QPI speeds	4.80 GT/s to 6.40 GT/s
DMI speeds	2 GT/s
Cache
L1 cache	64 KB per core (32 KB data + 32 KB instructions)
L2 cache	256 KB per core
L3 cache	2 MB to 24 MB shared
Architecture and classification
Technology node	45 nm
Microarchitecture	Nehalem
Instruction set	x86-16, IA-32, x86-64
Instructions	MMX, SSE, SSE2, SSE3, SSSE3, SSE4, SSE4.1, SSE4.2
Extensions	VT-x, VT-d
Physical specifications
Transistors	731M to 2300M 45 nm
Cores	1-6 (1-8 Xeon)
Sockets	LGA 1156 LGA 1366 LGA 1567 μPGA 988
Products, models, variants
Core names	Clarksfield Lynnfield Bloomfield Jasper Forest Gainestown (Nehalem-EP) Beckton (Nehalem-EX) Aubrurndale Havendale
Product code name	NHM
Models	Core i5-7xx Core i7-8xx Core i7-9xx Extreme Xeon 3000/5000/7000 Mobile Core i7-7xxQM Mobile Core i7-8xxQM Mobile Core i7-9xxXM Extreme
History
Predecessors	Core (tock) Penryn (tick)
Successors	Westmere (tick) Sandy Bridge (tock)
Support status
Unsupported

Nehalem /nəˈheɪləm/ 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 succeeds the older Core microarchitecture used on Core 2 processors. 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

• 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 reintroduced.
• 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.

Translation lookaside buffer sizes

Cache		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

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

Server, workstation, and desktop processors

• 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

See also

• List of Intel CPU microarchitectures
• Tick–tock model

References

1. I Am Nehalem
2. Gruener, Wolfgang (August 10, 2008), Nehalem = i7: Intel unveils new Core processor brand, TG Daily, archived from the original on August 14, 2009, retrieved August 11, 2008
3. Intel Details Upcoming New Processor Generations, Intel Corporation, March 28, 2007, archived from the original on October 6, 2009
4. Ian, King (October 20, 2008), Intel's new faster chip right on AMD's heels, The Seattle Times, archived from the original on June 22, 2011
5. Jones, George (February 9, 2008), IAMD vs Intel: The future of desktop CPUs, PC Advisor UK, archived from the original on June 23, 2008
6. "Archived copy" (PDF). Archived from the original (PDF) on November 29, 2015. Retrieved November 30, 2015.{{cite web}}: CS1 maint: archived copy as title (link)
7. Kanter, David. "Inside Nehalem: Intel's Future Processor and System".
8. Kanter, David. "Inside Nehalem: Intel's Future Processor and System".
9. Kanter, David. "Intel's Sandy Bridge Microarchitecture".
10. "Inside Nehalem: Intel's Future Processor and System". Retrieved December 29, 2014.
11. "Feature - Intel Core i7 - Nehalem Architecture Dive". bit-tech. Retrieved December 29, 2014.
12. "Intel Developer Zone". Intel.
13. "Intel's dual teamed approached to micro-architecture development", PC Watch (in Japanese), January 29, 2008
14. Botezatu, Bogdan (April 22, 2008), Intel: No Overclocking for Mainstream Nehalems, Softpedia
15. NO EXECUTE!
16. "Nehalem - Microarchitectures - Intel - WikiChip". en.wikichip.org. Retrieved February 9, 2021.
17. Johan De Gelas. "AnandTech - High-End x86: The Nehalem EX Xeon 7500 and Dell R810". Retrieved December 29, 2014.
18. AMD launches 12-core Opteron server chips, Intel counters with the 8-core Xeon 7500, engadedget.com, March 31, 2010, retrieved March 31, 2010
19. Nebojsa Novakovic (February 12, 2009), Intel's next bunch of fun CPUs moves to 2010, CNN International, archived from the original on March 4, 2009, retrieved March 1, 2009{{citation}}: CS1 maint: unfit URL (link)
20. Intel Xeon Processor 5500 Series Product brief, (Document Number: 321579-001US) (PDF), Intel, April 1, 2009, archived from the original (PDF) on October 9, 2016, retrieved August 27, 2010
21. Core i7 to make leap to Xeon in early 2009, Legacy.macnn.com, archived from the original on December 7, 2008, retrieved November 24, 2008
22. Fuad Abazovic (January 28, 2009), Nehalem based Xeon comes Mar 29th, Fudzilla.com, retrieved January 28, 2009
23. Intel Xeon Processor 3500 Series, Intel, April 1, 2009, retrieved April 10, 2009
24. ^ Teglet, Traian (November 13, 2008), Intel to Add New Nehalem Xeon Processor, softpedia, retrieved November 13, 2008
25. "Intel Core i7 Processor Extreme Datasheet, Volume 2, (Document Number: 320835-002)" (PDF). Intel. November 1, 2008. Archived from the original (PDF) on January 17, 2009. Retrieved March 24, 2009.
26. ^ Worrel, Jon (February 9, 2009), Core i7 950 and 975 to replace 940 and 965, Fudzilla, retrieved February 10, 2009
27. Intel to launch new Core i7 960 and Celerons, archived from the original on July 10, 2009
28. ^ Intel Quietly Announces Core i5 and Core i3 Branding, AnandTech, June 17, 2009
29. Intel Xeon Processor 5000 SequenceTechnical Documents, archived from the original on November 26, 2011
30. Intel Xeon Processor 5500 Series Datasheet Volume 2 (PDF), Intel, March 2009, archived from the original (PDF) on April 15, 2011, retrieved May 1, 2009

Further reading

• InfoWorld review: Intel's Westmere struts its stuff, InfoWorld, March 16, 2010
• IDF: Intel Clarkdale Up Close and Personal, X-bit Labs, September 24, 2009, archived from the original on March 8, 2011
• Intel Core i7 Processors: Nehalem and X58 Have Arrived, Hot Hardware, November 3, 2008, archived from the original on March 6, 2009, retrieved June 10, 2009
• Intel Core i7 CPU & Nehalem Architecture Review, hardCOREware.net, November 3, 2008, archived from the original on November 6, 2008
• Intel Nehalem Core i7 Series Complete Review, PC Perspective, November 3, 2008, archived from the original on November 6, 2008, retrieved November 3, 2008
• Intel Nehalem Core i7 940 Review, Xtreview, October 1, 2008
• Altavilla, Dave (March 17, 2008), Intel Showcases Dunnington, Nehalem and Larrabee Processors, HotHardware, archived from the original on May 23, 2012, retrieved March 26, 2008
• Shrout, Ryan (March 28, 2008), Intel Slides and Nehalem architecture information, PC Perspective, archived from the original on May 14, 2010, retrieved April 23, 2007
• Stokes, Jon (March 28, 2007), Intel drops a Nehalem bomb on AMD's Fusion: integrated graphics, on-die memory controller, SMT, Ars Technica
• Lal Shimpi, Anand (September 18, 2007), Nehalem: Single die, 8-cores, 731M transistors, AnandTech
• Lal Shimpi, Anand (November 3, 2008), Nehalem - Everything You Need to Know about Intel's New Architecture, AnandTech
• David Kanter (April 4, 2010). "Inside Nehalem: Intel's Future Processor and System". realworldtech.com. Retrieved December 16, 2010.
• Holland, Maggie (September 19, 2007), IDF 2007: Intel debuts Nehalem, IT Pro, archived from the original on October 18, 2007
• Everything we know about Nehalem (in Spanish), CHW.net, January 5, 2008, archived from the original on July 5, 2008
• Stokes, Jon (April 9, 2008), What you need to know about Intel's Nehalem CPU, Ars Technica
• Torres, Gabriel (March 17, 2008), Details on the Forthcoming Intel Nehalem Processor, Hardware Secrets, archived from the original on May 16, 2008
• Shimpi, Anand Lal (June 5, 2008), The Nehalem Preview: Intel Does It Again, AnandTech
• Shimpi, Anand Lal (August 21, 2008), Nehalem – Everything You Need to Know about Intel's New Architecture, AnandTech
• First Look at Nehalem Microarchitecture, X-bit Labs, November 2, 2008, archived from the original on November 6, 2008

External links

• Nehalem processor at Intel.com

• Intel x86 microprocessors
• Intel microarchitectures
• X86 microarchitectures
• Computer-related introductions in 2008