Review: Intel Core i7-4770K (22nm Haswell)

4th Gen Range

At launch, Intel is beginning the Haswell party by unveiling a range of mostly quad-core parts spanning the mobile and desktop product lines, with more-affordable, dual-core solutions expected to arrive at a later date.

For the time being, at least, Intel's fourth-generation mobile product stack is to be dominated by premium parts. It's intriguing that IGP performance has practically no correlation to processor price; the costliest Core i7-4930MX is actually equipped with the least capable IGP on show (HD 4600).

This eclectic mix of features makes it difficult to identify a processor's strong points based on price and core clock speed alone, so in its effort to balance three identified factors - power consumption, graphics performance and compute performance - Intel has introduced a long list of suffixes to better identify certain strengths. On the mobile side of things, the following stackable suffixes will be used on Haswell chips:

Mobile Haswell Processor Suffixes

• H - high performance Intel Iris graphics
• M - standard mobile processor
• Q - quad-core processor
• U - ultra-low-power SoC designed for Ultrabook
• X - extreme performance
• Y - lowest-power SoC designed for Ultrabook

We suspect a multi-million-dollar marketing campaign will be introduced to better explain why a Y-Series chip is a good fit, but one thing's for certain, it's no longer as simple as i3 is good, i5 is better and i7 is best.

On the desktop side of things, Intel is racing out of the gate with a dozen solutions, ranging from the 35W Core i5-4570T to the top-of-the-line, 84W Core i7-4770K. We've listed all 12 chips as well as a selection of previous-generation offerings for direct comparison.

The fact that each and every launch-day desktop Haswell processor is equipped with an HD 4600 IGP suggests that Intel believes consumers will want to pair the processors with a dedicated graphics card. Once again, distinguishing between features - which chips are multiplier unlocked, which are low-power, etc - is easier said than done. Intel has five further suffixes that it uses to illustrate certain variables:

Desktop Haswell Processor Suffixes

• No suffix - standard processor aimed at the mainstream
• K - multiplier unlocked, providing greater overclocking potential for enthusiast users
• P - no integrated graphics processor
• R - high performance Intel Iris graphics, BGA package
• S - "performance optimised lifestyle," features a lower CPU base frequency and a reduced TDP
• T - "power optimised lifestyle," features a lower CPU base frequency, a lower Turbo Boost frequency and a greatly-reduced TDP

The desktop range has a couple of interesting letters on show. K continues to be the series of choice for overclockers (more on that later), while S and T highlight reduced TDP and greatly-reduced TDP parts, respectively.

What's new is the R-series. At launch, there will be a Core i7-4770R that, while technically a desktop product, won't be available to purchase as a standalone solution; it's served in a BGA package and available to OEMs. The 65W Core i7-4770R is an interesting chip, in that it is the only 4700-series part to feature Intel Iris Pro 5200 graphics, making it an obvious choice for high-performance all-in-one PCs.

Haswell continues to hold promise for thin, compact and stylish turnkey solutions, but there are a few sticking points for enthusiast self-builders. First and foremost, Haswell will launch at higher price points than the two previous-generation equivalents. In thousand-unit quantities, the new Core i7-4770K will ship at $339, compared to the launch price of $313 for a Core i7-3770K and $332 for a Core i7-2700K. Opting instead for a Core i5 saving? Then prepare for a similar hike: the Core i5-4670K launches at $242, compared to the previous $212 for a Core i5-3570K and $216 for a Core i5-2500K.

Motherboard and PSU provisos

As you're no doubt aware, desktop Haswell processors are shipped to work with a new LGA1150 socket - meaning, yes, you once again need a new motherboard to utilise a new Intel chip.

We'll cover the new top-of-the-line Z87 chipset shortly, but before we get there, consumers should note that Intel identified a flaw in the 8-series chipset that affects the behaviour of attached USB 3.0 devices. During testing, engineers confirmed that, in some instances, when USB 3.0 devices were removed from the PC back panel they were not being properly disconnected from the device manager and would show as remaining in a connected state.

We're told that there is no risk of data loss or corruption, and the issue won't result in a repeat of the Sandy Bridge chipset recall fiasco. However, Intel did issue a product change notification back in April, to initiate a C1 to C2 stepping conversion for 8-series chipsets. This revision fixes the USB 3.0 problem, but with production already having ramped up, motherboards with the C1 stepping are likely to be in circulation at launch. It remains unclear as to whether or not board manufacturers will actively identify updated C2 models, or whether C1 stock will be cleared at a discount, but it's worth bearing in mind when you're shopping for your new platform.

Similarly, you'll want to choose your power supply carefully, too. Haswell's super-low-power operating states mean that cheaper supplies can run out of voltage kilter on the +12V rail when the CPU is brought out of power states that can consume as little as 0.05A. This problem is only potentially apparent if there is concurrent load on the minor +3.3V and +5V rails at that time, which can lead to a spike on the 12V rail on inferior supplies. What the consumer needs to look for is a PSU with what's known as DC-to-DC conversion, which means that all rails are derived from the +12V line. Most high-quality PSUs tend to have this architecture, but please do check with manufacturers for Haswell low-power compatibility. Note that popular brands such as Corsair now offer a Haswell compatibility table.