Everything you need to know about the fourth generation of PC processors from Intel.
Haswell is Intel's new family of processors targeted at the PC and server market. With Haswell Intel has designed a processor suited to new PC form factors – laptops no thicker than 25mm, PC/tablet hybrids, pure tablets and all-in-one PCs.
In particular Intel has targeted the fourth generation chip at serving what it calls the 'ultrabook' market. Intel defines ultrabooks as mobile computers thinner than 25mm, with touchscreen and voice control as standard and possibly convertible into either a tablet or laptop.
What's Haswell's USP?
Better battery life. Compared to the Intel's previous PC processors based on the Sandy and Ivy Bridge microarchitecture, Haswell sucks up less power.
A Haswell U-series processor designed for ultrabooks, an Intel Core i7-4650U, can sustain 9.1 hours of HD video playback and more than seven days of standby, according to Intel. That's three hours more of video playback and 1.5 days more standby than a previous generation Intel Core i7-3677U running on the same battery.
The average application – media player, web browser or office application - running on a Y-series Haswell processor, the lowest power Haswell processor series, should consume around six watts, Intel predicts.
The lower energy consumption is particularly important for a processor designed to be squeezed into thin laptops and tablets, as pushing down power draw means cooler chips and reduces the heatsink and fan size, as well as allowing tablets to operate fanlessly.
What else is Intel promising for Haswell ultrabooks?
Haswell-based ultrabooks and tablets will be able to "wake" from sleep in under three seconds, compared to the seven seconds it took devices based on previous gen Intel processors to wake. This is thanks to "extremely low power" state, known as S0ix.
Applications running on a Haswell system will also be able to receive data while in this low-power, so an email client would be able to refresh its list of emails while in this mode.
So Haswell's all about battery life?
No, the other standout feature of the new processors is the performance of their integrated graphics cores. The highest end graphics core, the Iris Pro, is capable of running some of the latest games without a dedicated graphics card, albeit not at the highest settings, roughly matching the performance of a sub-£100 card.
Game benchmarks at 1080p released by Intel show the Iris Pro delivering an average of 131 FPS in Call of Duty Modern Warfare 3 at medium detail settings and 38FPS in the latest Tomb Raider game at medium settings.
The integrated graphics are a good deal more powerful than Intel's earlier offerings. The second most powerful Haswell graphics core, the Intel Iris HD5100 in a 28W i7-4558U, delivered twice the performance in 3DMark 2011 of an integrated graphics core in an Intel third generation i7-3687U.
All Intel Haswell processors include integrated graphics cores based on a new chip design. The performance of these cores vary, from the high end Intel Iris Pro and Intel Iris variants, found in select Core i7/i5/i3s, to the lowest level Intel HD Graphics. These cores support DirectX11.1, OpenCL 1.2, OpenGL 4.0, a three collage screen display and enhanced 4K by 2K resolution. The graphics chip also includes faster Intel Quick Sync Video and JPEG/MPEG decode and transcoding.
What about desktop PCs?
There will be a range of Core i7 and i5 desktop processors. The enthusiast K-series processors with an unlocked multiplier to make them easier to overclock, the low-power 35W and the 45W (quad core) T-series processors, the quad core 65W S-series and the quad core 65W R-series with an Intel Iris Pro graphics core. All the other desktop processors have the lower end Intel 4600 HD integrated graphics.
As would be expected Intel also claims improved performance for the desktop processors – a 65W Haswell Intel Core i5-4570S is some 2.2 times faster at running office apps, 9.2 times faster at editing video and has 21 times better 3D performance in games than a 65W Intel Core 2 Duo processor E8400.
Intel envisages that Haswell desktop chips will generally be used inside HD touchscreen all-in-one PCs with integrated voice control, rather than the tower PCs of old.
Does Haswell have a role in the datacentre?
The only family of Haswell processors targeted at servers launched to date is the Intel Xeon E3-1200 v3.
The Xeon E3-1200 is being billed as offering the lowest-power Intel Xeon processor to date ranging down to the 13W TDP, 1.1GHz E3-1220LV3 processor designed for use within microservers and communications infrastructure.
The processor family's integrated graphics capabilities are designed to suit serving video to different devices in a wide range of formats. The chips' integrated Intel HD 4600/4700 graphics core includes fixed function hardware accelerators for AVC (H.264) media transcoding, MVC (Blu-Ray 3D) and MPEG-2 hardware encoding and JPEG and MPEG hardware encoding. Intel claims a 65W Haswell E3-based server carried out 25 percent more transcodes than a 290W server with a nVidia GTX680 card in tests.
Processors in the E3 family range from the quad core 3.5GHz E3-1275V3 with 84W TDP down to the dual core 1.1GHz E3-1220LV3 with 13W TDP.
Intel is claiming general efficiency and performance advatages over previous generation E3 processors, with the Haswell 25W E3 CPU delivering up to 52 percent performance per watt advantage over the previous generation 45W processor. While the E3-1220LV3 will not be available until the third quarter of 2013 the rest of processors are available now.
What's changed on the technical side?
Haswell is the successor to the Sandy Bridge architecture, and will initially be built on the same 22nm process as Ivy Bridge (the die shrink of Sandy Bridge).
While the chip's architecture has similarities to Sandy Bridge Intel has made changes within the cores to scale up performance and efficiency.
These changes include increasing the depth of the cores' buffers to give flexibility to its out-of-order execution – the chip's ability to optimise the flow of data and instructions. The chips also feature improved branch prediction – where the chip predicts the correct path for data, which boosts performance by reducing the number of times a chip needs to start an incorrect branch again.
Haswell also increases the number of operations that can be executed per clock cycle to eight, up from the six using Sandy and Ivy Bridge.
Another key feature in the Haswell architecture is the addition of fused multiply-add (FMA) floating point operation units. These provide the ability to add and multiply in the same cycle, which reduces the number of clock cycles needed to perform floating point calculations and improves mathematical precision.
The bandwidth available to the fourth generation processors' L1 and L2 cache has also been doubled over Sandy and Ivy Bridge, while the size of the cache remains the same.
Haswell will use 3D Tri-Gate transistors and include Haswell New Instructions (AVX2) for enhanced vector floating-point performance, Transactional Synchronization Extensions, which adds hardware transaction memory support and shifts some of the responsibility for managing parallel processing from software to the hardware, better virtualisation performance and EPT (Extended Page Tables). Haswell will move to a 14nm process, codenamed Broadwell, in 2014.
What does Haswell mean for Intel?
The jury is out, but the question remains as to how a number of factors will affect Haswell sales: namely flagging demand for traditional desktop PCs, to what extent consumers will be won over by sleek ultrabooks with a long battery life and whether Intel can capture market share in the hybrid and tablet market with the low-power Y-series Haswell processors.
There's no guarantee that consumers still want to buy the sort of devices that Haswell will power, said Roy Illsley, principal analyst for software and IT solutions at Ovum.
"I guess the question is more will the PC market still command sufficient importance to justify Haswell. I think we are entering a world of people using many different devices, which will begin to contract as the price/performance of ultrabooks and tablets becomes more appealing," he said.
Gartner principal research analyst Sergis Mushell believes that the performance and battery life offered by Haswell processors could stimulate the market for hybrid laptop/tablet PCs.
"Haswell enables designs in which PC vendors can offer to the market place products which can offer the performance and content creation abilities of a PC and can be converted in to a tablet for consumption," he said.
But while Haswell promises thinner, flexible PC-cum-tablets with greatly improved efficiency, these advantage comes at a price. Two higher end processors aimed at ultrabooks are the Core i7-4650U (2.9GHz base, 3.3GHz turbo, 4MB cache) and the Core i5-4350U (2.6GHz base, 2.9GHz turbo, 3MB cache). These are priced at $454 and $342 respectively for OEM's buying a tray of 1,000 processors.
The equivalent previous-generation Ivy Bridge parts, the Core i7-3687U and the Core i5-3437U, are priced at $346 and $250 respectively.
That's something of a premium for price-conscious consumers in the age of good enough computing. Then again there are cheaper ultrabook processors. And Intel isn't betting the farm on Haswell, it also has its energy efficient Baytrail platform based on Silvermont, its new Atom microarchitecture, to challenge Arm in the mainstream tablet and mobile space.