Intel kicks off eighth-gen Core with four cores and eight threads in 15W


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— 2:01 AM on August 21, 2017

Intel is kicking off its eighth generation of Core processors this morning. Contrary to recent buzz, however, the four chips the company is debuting today aren't Coffee Lake CPUs, or even desktop parts. In fact, the eighth generation of Core CPUs won't refer to a single internal code name, or even a single process generation.

Instead, this generation of chips marks the first where Intel is defining a generational leap by the potential performance increase delivered at  a given power level. To get there, Intel might use 10-nm process technology in some chips and refined 14-nm technology in others. We might even see different core architectures to go with those different processes. This will surely be a headache to keep track of, but Intel figures customers won't care where the performance increases come from so long as there is a performance increase, watt-for-watt.

  Base
clock
speed
Maximum
Turbo
speed
Cores/threads Cache size Memory
channels
Memory
type
Onboard
graphics
processor
Max
graphics
frequency
Core i7-8650U 1.9 GHz 4.2 GHz 4/8 8MB 2 DDR4-2400
or
LPDDR3-2133
Intel UHD
Graphics 620
Up to 1150 MHz
Core i7-8550U 1.8 GHz 4.0 GHz
Core i5-8350U 1.7 GHz 3.6 GHz 6MB Up to 1100 MHz
Core i5-8250U 1.6 GHz 3.4 GHz

With all that out of the way, we can talk about the four CPUs Intel is unveiling today. These are 15W U-series parts using cores that Intel calls "Kaby Lake refresh." As that name would suggest, very little has changed in the architecture of these chip. Much as it did in the transition from Skylake to Kaby Lake, the company has further refined its "14-nm plus" process node to extract more performance within a given power envelope.


The Kaby Lake refresh die. Source: Intel

Even if the functional units of the Kaby Lake refresh chips are largely similar to those of their predecessors, Intel is also using its refinements to cram more of them onto a chip. As you can see in the die shot above, those refinements have made it possible for Intel to squeeze four cores and eight threads into 15W Core i5s and Core i7s. That's a mind-blowing development when you think about it. Even in the seventh generation of Core CPUs, 15W bought you at most two cores and four threads of processing power. To have four cores and eight threads on Core i5 and Core i7 U-series chips alike is a major step forward for the lightweight 2-in-1s and ultrabooks that will likely serve as hosts for these parts.

The key figure you'll hear Intel hammering home with these chips is a performance improvement of up to 40% over Kaby Lake U-series CPUs. The majority of that increase comes from the two extra cores the company is packing into 15W, but design and process refinements purportedly let the company extract another 15% more performance for the 40% total. Depending on how much stock you put in Sysmark, the Core i7-8550U could deliver as much as a 100% performance increase over the five-year-old Core i5-3317U.

The claimed performance gains don't stop there, of course. The company says the QuickSync encoder in the i7-8550U can export a 4K HEVC video in just three minutes using Cyberlink PowerDirector, compared to the whopping 45 minutes required for a CPU encode on that same i5-3317U. Intel also says the i7-8550U knocks out its internal Adobe Lightroom export benchmark 2.3 times faster than the i5-3317U and 28% faster than an i7-7500U. Those sound like formidable performance improvements for ultrabook-class machines.

The cost of four cores in such a slim power budget are the low base frequencies of these chips. Last generation's Core i7-7600U boasted a lower peak Turbo speed than the i7-8650U at 3.9 GHz, but its 2.8 GHz base speed is a whopping 900 MHz higher than the eighth-gen chip's. Just how pessimistic that figure is will likely depend on manufacturers' cooling implementations.

Still, four cores and eight threads running at 33% or lower base clock speeds than last generation's dual-core chips could still provide a favorable performance increase in the heavily-threaded tasks likely to push clocks toward Intel's base figures. They could also bode well for powering demanding workloads like gaming on an external graphics card, a use case that's becoming more popular by the day.

Most critically, Intel claims that the added hardware doesn't hurt battery life. Eighth-gen U-series Core chips will purportedly deliver the same 10 hours of battery life in notebooks that Kaby Lake CPUs could.

Observant readers will also note that Intel is now branding its onboard graphics processors as "Intel UHD graphics." This feature doesn't reflect any new capabilities in the graphics processor itself—this is still the same Gen9 IGP present in today's Kaby Lake chips. "UHD graphics" is a branding exercise meant to get across the idea that eighth-generation Core CPUs are ready for 4K and HDR video streaming from services like Netflix, Sony Ultra, Funbox UHD, and iQiyi. Amazon Prime Video and Vudu will soon add support for Intel integrated graphics processors, as well. These IGPs can even run Microsoft's entry-level Windows Mixed Reality VR headsets, too.

Contrary to many rumors, Intel didn't discuss upcoming changes in its desktop processor lineup or set new desktop products for launch today. The company says those products are coming "this fall," but more precise details remain evasive. We should expect higher-TDP and business-ready product lines to arrive on that timeline, as well.

Intel expects that over 145 notebook designs using eighth-gen Core U-series chips will eventually make their way into market, and 80 of those should be in the market by the holiday season. Those products will begin rolling out next month. Stay tuned for more coverage as we see how manufacturers choose to implement these faster and wider CPUs soon.

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Tags: CPUs