Power Consumption, Perf per Dollar, Closing Thoughts

Power Consumption Testing

At both idle and under a full load, the Core i7-7700K and Core i7-6700K essentially use the same amount of power. The changes to the 14nm process technology that Kaby Lake takes advantage of didn't go towards lowering the TDP (both parts are listed at 91 watts according to Intel) but instead to the slight increase in clock speed.

Performance per Dollar

One thing we wanted to take into consideration with this review is the idea of performance per dollar.  To get some interesting data I selected three benchmarks (7zip, Cinebench 11 and x264 v5.0) and included current pricing from Newegg.com (or Amazon if out of stock on Newegg).

At $339, the Core i7-7700K is priced right in line with previous Intel mainstream CPU releases including the Core i7-6700K, 4790K and 3770K. It's obvious that those Extreme Edition processors have a hell of a hill to climb with their $1000+ price tags.

It should come as no surprise based on the results on the previous pages that the Core i7-7700K and the Core i7-6700K have the same value proposition. They perform within 3-5% of each other in most tests and the prices are the same (in terms of Intel pricing at least). It will be interesting to see how the 7700K pricing scenario plays out and if the somewhat moderate excitement for the CPU means the typical day-one price jumps will be avoided.

The new feature: HEVC Decode

Segment taken from our Kaby Lake notebook analysis last month.

The primary differentiation point for the graphics and media block of Kaby Lake is the inclusion of an HEVC hardware encode/decode block. This takes the work off of the CPU cores and puts it on dedicated hardware, offloading the CPU and lowering power consumption and utilization.

How much do you ask? To test, I simply recorded some performance monitors from Windows 10 and played back a 4K 24FPS 20mbps 10-bit HEVC (H.265) video file in the Windows Movies & TV app. The result speaks for itself.

Wow! While the new Kaby Lake system was able to playback the movie using less than 10% of the CPU, the Skylake system required ~45% to get the job done. And to be honest, there were some places where I saw dropped frames on Skylake as well – not a perfect viewing experience. It has been a while since we have seen simple video playback hit CPU utilization levels like this.

As you might imagine, this kind of CPU utilization gap will translate to a HUGE amount of battery life advantage for Kaby Lake notebooks while watching similar video. Even upcoming VP9 content being pushed by Google will see this kind of edge on Kaby Lake systems with the dedicated decode block, another capability missing from previous architectures.

Our sample footage, Tears of Steel

Even though HEVC content is still in its infancy, its growing rapidly and the adoption by Google and other third parties will likely accelerate it in 2017.

The potential power savings for this on desktop systems is less important for sure, but a great feature to have if you want to playback video while doing other moderately CPU intensive tasks on your machine at the same time.

Pricing and Availability

As it turns out, the Core i7-7700K has been showing up for sale for about a week prior to this review going live. 

I will try to update the pricing links to additional Kaby Lake parts as the day goes on and as they show up at online retailers.

Closing Thoughts

This is an interesting conclusion to write. On its surface, the Core i7-7700K and the Kaby Lake-S platform have very few advantages over the current shipping versions of Skylake. The processor has no drastic performance improvements over the 6700K and in our testing is only 3-6% faster, sometimes falling just *slightly* behind. There are no thermal or power consumption advantages – you won't be saving power or running at lower temperatures with Kaby Lake than you would with Skylake. The only feature addition is support for hardware accelerated HEVC decode allowing you playback high bit-rate movies and VP9 online video with fixed function hardware, lowering total CPU utilization. But for consumers that choose to use discrete graphics, which I assume will be most buyers of the 7700K, that advantage is minimized too.

The overclocking performance I saw with my processor was impressive and using the Z270 motherboard that ASUS provided I was able to get the 7700K to run at 5.1 GHz completely stable through a bevy benchmarks and applications. Even discounting the allure of running a processor at 5.0+ GHz without getting into LN2, the 13-16% performance uptick from that slight push is definitely worth trying for. There will be variance between all the Kaby Lake parts in the wild, but based on my talks with ASUS and others, 5.0 GHz is a very achievable state for most silicon that has been tested.

Our positive results from SYSmark 2014 SE show the potential for Kaby Lake to outshine Skylake and other processor architectures when painted in a specific light. The question is how much of that will matter to OEMs or to consumers.

In the end, if you are building a new system today from scratch, it makes sense to go with the Core i7-7700K or an equivalent Kaby Lake processor and a Z270 motherboard. It's the new "best option" for mainstream consumers and PC gamers, even though the improvement over Skylake is questionable in some area. Add in the fact that you'll be ready for Intel Optane memory with that combination and you might find Kaby Lake a bit more enticing later in the winter. 

If you are a gamer or enthusiast sitting there with a Skylake or Haswell CPU, this isn't enough of a spark to get you itching for an upgrade.

Everyone welcome Kaby Lake, the new "best" that's hard to get excited about.

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