Kaby Lake

THE VER­DICT

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Fastest ever desk­top CPU

Why you should up­grade

You’ll never need a graph­ics card again

8-PAGE RE­VIEW FULL BENCH­MARKS

In­tel’s re­cent roll­out of the sev­enth-gen­er­a­tion Kaby Lake CPU for desk­tops has met with a muted re­sponse from leaked re­views that dis­miss the new chip as one huge Core i-Yawn. Kaby Lake seems to of­fer barely any move­ment for­ward, and when it’s over­clocked, it ap­par­ently gets to nu­clear-fu­sion lev­els of heat out­put. It is, how­ever, too early to write off Kaby Lake. There’s a lot more to it that you still need to know.

What Kaby Lake brings to the desk­top

Kaby Lake launched in Au­gust 2016 with dual-core ver­sions for lap­tops that of­fered rea­son­able per­for­mance upticks. The high­light is its video en­gine, which can han­dle 10-bit con­tent with­out break­ing a sweat. Play a 10-bit colour depth file on a Sky­lake lap­top with in­te­grated graph­ics, and you drop frames and de­stroy bat­tery life. The same video on Kaby Lake hums along with far less im­pact. You can see this demon­strated at (tinyurl.com/z4tr9bL). The up­dated graph­ics core with the lat­est con­tent pro­tec­tion can now stream 4K from ser­vices such as Net­flix.

On the desk­top side, how­ever, power users don’t care about in­te­grated graph­ics, fo­cus­ing more on the lack­lus­tre x86 per­for­mance. To be fair, In­tel set the ex­pec­ta­tion in Au­gust that Kaby Lake was ba­si­cally Sky­lake on an im­proved process that squeezes out more mega­hertz.

For ex­am­ple, the top-end Core i7-7700K has a base clock speed of 4.2GHz and a Turbo Boost clock speed of 4.5GHz, ver­sus

a Sky­lake Core i7-6700K’s base clock of 4GHz and Turbo Boost of 4.2GHz.

The cache size, the core count, the mem­ory con­troller and even the same LGA1151 socket are un­changed from the pre­vi­ous chip.

This is the real launch

In­tel fleshes out the Kaby Lake line-up with a to­tal of 42 CPUs: 17 ul­tra low-power chips for lap­tops, two quad-core Xeons, seven quad-core lap­top CPUs, and 16 desk­top CPUs.

Of par­tic­u­lar in­ter­est in that desk­top line-up to do-it-your­selfers are the three un­locked K chips. The first two were ex­pected: a quad-core with 4.2GHz Core i7-7700K with Hy­per-Thread­ing and a quad-core 3.8GHz Core i5-7600K with­out Hy­per-Thread­ing. The third is a sur­prise: the dual-core 4.2GHz Core i3-7350K. The CPU has Hy­per-Thread­ing but since it is a Core i3, does not have Turbo Boost en­abled.

This isn’t In­tel’s first ‘bud­get’ over­clock­ing chips, though. The com­pany in­tro­duced the dual-core Pen­tium G3258 An­niver­sary Edi­tion in 2014 and as early as 2010, In­tel sold the dual-core Core i5-655K.

The new Z270 is ‘Op­tane-Ready’

With Kaby Lake for desk­tops, In­tel is in­tro­duc­ing new 200-se­ries chipsets to re­place the 100-se­ries chipsets that were in­tro­duced with Sky­lake. Like Kaby Lake, it is an in­cre­men­tal up­date that dis­ap­points a bit.

We ex­pected the 200-se­ries chipsets to fea­ture na­tive sup­port for USB 3.1 10Gb/s or maybe even Thun­der­bolt 3, but no. In­stead, mother­board mak­ers will have to add ad­di­tional chips for those func­tions.

From what we can tell, there are three key changes to Z270. The first is an up­grade from the 20 lanes of PCIe Gen 3 in the Z170 to 24 lanes in the new per­for­mance Z270 chipset. The move will let mother­board mak­ers in­te­grate high­band­width con­nec­tions such as M.2 or U.2 with­out hav­ing to share band­width be­tween de­vices. In­tel says it has also im­proved over­clock­ing ca­pa­bil­ity.

The last up­grade is of­fi­cial ‘Op­tane-ready’ sup­port. What that means isn’t ex­actly clear, but we do know In­tel’s Op­tane (a non­volatile mem­ory that prom­ises much higher per­for­mance than SSDs) will go into an M.2 slot on the board, where it can be

used as a tra­di­tional stor­age de­vice or as a way to ac­cel­er­ate sys­tem per­for­mance, much like what’s done to­day with In­tel’s Smart Re­sponse Technology, which uses a solid-state drive (SSD) to cache per­for­mance from a tra­di­tional hard drive.

That doesn’t mean Op­tane won’t work in other sys­tems us­ing older chipsets, but In­tel is likely to sup­port it only for ‘sys­tem ac­cel­er­a­tion’ on Z270 ini­tially.

If none of th­ese sound like much of an up­grade to your ex­ist­ing Z170 mother­board, the good news is you don’t have to buy a Z270 mother-board. Kaby Lake drops into most LGA1151 Z170 moth­er­boards and works just fine, as long as you’re us­ing an up­dated BIOS that sup­ports the new CPU.

How we tested

For our per­for­mance test­ing, we fo­cused on how Kaby Lake does against the CPU it re­places: we dropped the Core i7-7700K into the same Asus Z170 Deluxe mother­board that the Sky­lake chip was first tested with. The CPU was cooled with a Cor­sair H80i closed liq­uid cooler and out­fit­ted with 16GB of Cor­sair DDR4/2133 RAM, a ref­er­ence GeForce GTX 980 card, and a 256GB HyperX SSD. The op­er­at­ing sys­tem was Win­dows 10 run­ning the TH2 build.

Cinebench R15 multi-core per­for­mance

Our first test is Maxon’s Cinebench R15. It’s a bench­mark based on Maxon’s pro­fes­sional Cine­ma4D ren­der­ing en­gine and is a pure CPU test. We recorded scores from many of In­tel’s high-end quad-core main­stream chips and from chips with more cores, for con­text.

Among the quad-cores, the Core i7-7700K was the win­ner by the ex­pected amount. The Kaby Lake CPU is roughly 4- to 5 per­cent higher in clock speed and roughly 4- to 5 per­cent faster in Cinebench. When you look back to the Core i7-2600K though, it’s a huge 42 per­cent dif­fer­ence in per­for­mance. Stock clock per­for­mance be­tween the Kaby Lake, Sky­lake and Devil’s Canyon though, isn’t ex­actly go­ing to set the world on fire.

Cinebench R15 sin­gle-core per­for­mance

One er­ror with fo­cus­ing ex­clu­sively on multi-core per­for­mance is re­al­ity doesn’t match that. The vast ma­jor­ity of ap­pli­ca­tions are lucky to ex­ploit more than a sin­gle thread, in­stead favour­ing higher clock speeds and more ef­fi­cient CPU cores. Once we set Cinebench R15 to run in sin­gle-threaded

mode, the quad-cores with their higher clock speeds jump to the front of the line, with the Core i7-7700K now lead­ing the pack. For most peo­ple, those who don’t do 3D ren­der­ing or other heav­ily mul­ti­threaded tasks, a quad-core with higher clock speeds is the right choice.

There isn’t a lot of day­light be­tween the Core i7-7700K and the Core i7-6700K. Note, too, that our 10-core Broad­well-E Core i7-6950X was per­formed with­out Turbo Boost Max. Turbo Boost Max lets the CPU greatly in­crease the clock speed on a sin­gle core, bring­ing per­for­mance a lot closer to the quad-cores.

POV Ray per­for­mance

Another CPU-heavy test we use is POV Ray. It’s a ray-trac­ing pro­gram that traces its roots back to the Amiga. Our bench­mark set is a lit­tle smaller but no sur­prise, the Kaby Lake, with its 4- to 5 per­cent clock speed ad­van­tage, fin­ishes the test about 4- to 5 per­cent faster, putting the Core i7-7700K just barely be­hind a six-core Ivy Bridge-E Core i7-4960X.

As with Cinebench R15, we also run the test us­ing a sin­gle-threaded work­load. With lighter loads the CPUs can run at higher clock speeds and no sur­prise, the pair of quad-cores take the lead. Again, we saw maybe a 5 per­cent ad­van­tage for the Core i7-7700K over the Core i7-6700K.

Blender per­for­mance

Our fi­nal ren­der­ing test uses Blender 2.77a and Mike Pan’s BMW work file to mea­sure how fast the var­i­ous CPUs can ren­der a sin­gle frame us­ing the free and pop­u­lar Blender app. The Core i7-7700K again pulls ahead of the Core i7-6700K by a small per­cent­age, well within what we ex­pected for its clock-speed ad­van­tage. And yes, that six-core Ivy Bridge-E Core i7-4960X is re­ally start­ing to look mouldy here. One thing we’d like to point out about Blender is that it doesn’t show the scal­ing with thread count as much as Cinebench R15. While the 10-core Core i7-6950X is the win­ner here, it’s not as im­pres­sive as we would have ex­pected for a £1,600 CPU.

Hand­Brake 10.2 per­for­mance

Turn­ing to video en­cod­ing, we used the pop­u­lar and free Hand­Brake 10.2 en­code to con­vert a 30GB MKV file us­ing the An­droid tablet pre­set. The Core i7-7700K again comes in slightly ahead of the Core i7-6700K. There’s also a pretty healthy dis­tance be­tween the Kaby Lake chip and the still-ex­cel­lent Devil’s Canyon chip. The older Ivy Bridge-E Core i7-4960X dis­ap­points yet again, es­pe­cially con­sid­er­ing that it has six cores yet is ba­si­cally tied with the quad­core Kaby Lake chip.

WinRAR Per­for­mance

You should have the idea by now that the 4- to 5 per­cent clock in­crease from Sky­lake to Kaby Lake pretty much yields a 4- to 5 per­cent in­crease in per­for­mance across the board, so our last CPU-only test is WinRAR. Un­like the other tests, where we ran the ex­act same app our ma­chines, th­ese re­sults in­clude both 5.21 and 5.31 re­sults (for the Core i7-5775C and Core i7-4790K). The only dif­fer­ence be­tween 5.21 and 5.31 ap­pears to be bug fixes that don’t im­pact the built-in bench­mark. Un­like Cinebench, POV Ray, or Blender, WinRAR is a lit­tle more sen­si­tive to mem­ory band­width.

Both the Sky­lake and Kaby Lake CPUs are pretty much dead even here. We also see the Devil’s Canyon chip is more than 15 per­cent slower than the Sky­lake and Kaby Lake chips. The sur­prise, for the quad-core CPUs, is the Core i7-5775C Broad­well CPU. De­spite its lower clock speed of 3.3- to 3.7GHz, it’s lead­ing the pack of quad-core chips.

That isn’t some magic of the Broad­well mi­cro-ar­chi­tec­ture, though. It’s likely due to the large amount of em­bed­ded DRAM cache In­tel put into the CPU.

3DMark per­for­mance

Gam­ing in this day and age is still 90 per­cent about the GPU, which is why we ran 3DMark Fire Strike. All of the ma­chines used ref­er­ence GeForce GTX 980 cards and the same driver. As you can see, it’s mostly a tie. The 10-core Broad­well-E gets a small ad­van­tage be­cause 3DMark fac­tors the physics per­for­mance into the over­all score, but this is mostly a tie.

Be­cause this is a CPU re­view, we also de­cided to break out the physics per­for­mance, which favours core count over clock speed. No sur­prise, the 10-core comes out on top. If you’re look­ing at th­ese two charts and try­ing to de­cide how they should in­flu­ence your buy­ing or build­ing de­ci­sion, we’d say the graph­ics score is far more im­por­tant so long as you have a de­cently pow­ered quad-core chip.

Tomb Raider per­for­mance

We also fired up the slightly older Tomb Raid and ran the built-in bench­mark at 1080p res­o­lu­tion at the Nor­mal qual­ity set­ting. We chose Nor­mal rather than Ul­tra to try to make this more about the CPU than the GPU.

The Core i7-7700K again leads the pack for quad-cores but it’s re­ally no big deal.

The IPCs have it

CPU nerds like to talk about IPC, or in­struc­tions per cy­cle of a CPU. It’s one way to gauge ef­fi­ciency at a given clock speed. We took the per­for­mance of each CPU run­ning the Cinebench R15 test in sin­gle- threaded mode with Turbo Boost switched off on all of the CPUs. As we said with the Sky­lake Core i7-6700K re­view, it’s a pretty sober­ing wake-up call to see just how slowly IPC is inch­ing along in mod­ern CPUs.

The good news for mod­ern pro­ces­sors is IPC isn’t the only place you can pick up per­for­mance. Clock speed, core count, and abil­ity to hold Turbo Boost speeds longer have all added up to bet­ter per­for­mance. Here’s that re­minder seen in the first chart we ran from Cinebench R15, when each CPU is al­lowed to run un­fet­tered rather than locked down to a fixed fre­quency.

Over­clock­ing per­for­mance

Many of the early un­sanc­tioned re­views of Kaby Lake gave it a black mark for gen­er­at­ing ex­ces­sive heat when over­clocked.

We have al­ways been re­luc­tant to of­fer judg­ment about the over­all over­clock­ing per­for­mance of an en­tire CPU se­ries when work­ing with a sam­ple of one. Com­bine that with new moth­er­boards, new BIOSs and the dizzy­ing amount of mis­takes a re­viewer can make, and you can see why we think it’s un­fair to de­cide on an en­tire line based on one CPU and early moth­er­boards.

Still, in an at­tempt to get a feel for how Kaby Lake will over­clock for most, we spoke to two PC OEMs and a mother­board maker who have been try­ing to over­clock the CPU for far longer and with far more sam­ples.

The Kaby Lake re­sults they’ve seen were quite good. Many of their chips hit 5GHz

or got very close. Mother­board maker Asus, in fact, will fea­ture over­clock­ing pro­files that should make over­clock­ing a lot sim­pler.

“Through rig­or­ous test­ing, Asus en­gi­neers have fine-tuned a pro­file that al­lows Kaby Lake CPUs to over­clock to 5GHz with an 80 per­cent suc­cess rate,” the com­pany said. This is ac­tu­ally a great sign for prac­ti­cal over­clock­ers be­cause 5GHz over­clocks haven’t been seen since the days of the Core i5-2500K and Core i7-2600K. Both of which could seem­ingly run at 4.5GHz on air or 5GHz with liq­uid cool­ing.

You can’t say the same about the CPUs that fol­lowed Sandy Bridge. Ivy Bridge and Haswell both hit walls at 4.5GHz for most peo­ple. Devil’s Canyon was sup­posed to break the 4.5GHz bar­rier but all we got were chips that could get closer to 4.5GHz but not sur­pass it. Broad­well didn’t count (it didn’t ship in great vol­ume), and Sky­lake also hit that same in­vis­i­ble bar­rier at 4.5GHz.

With its mas­saged 14nm process, Kaby Lake fi­nally seems to break that mag­i­cal bar­rier. To prove it, we had two sys­tem builders send two pro­duc­tion PCs that could break the 4.5GHz bar­rier. Both did. The first sys­tem, for ex­am­ple, was able to with­stand al­most four hours of con­tin­u­ous Hand­Brake en­codes with all cores locked at 5GHz with­out is­sue. The sec­ond ma­chine could hit 5GHz in a small-form-fac­tor box.

Run­ning at 5GHz, the Kaby Lake will match a six-core Ivy Bridge-E in per­for­mance. In sin­gle-threaded ap­pli­ca­tions at 5GHz, the re­sults are even more im­pres­sive.

Does this mean your chip will hit 5GHz? No. Re­mem­ber, it’s al­ways been a lottery sys­tem with over­clock­ing re­sults, but the word from ex­pe­ri­enced bou­tique PC builders and Asus is far more promis­ing than it’s been in a long time.

As much as ev­ery­one wants to be a hater, it’s look­ing very much like Kaby Lake, for those who want to go there, can break 4.5GHz at last.

Umm, how much again?

So we have an of­fi­cial, sanc­tioned view of just how a desk­top Kaby Lake per­forms. Now, what ev­ery­one wants to know is how much. There is, again, more dis­ap­point­ment.

The ini­tial prices the press was given for Kaby Lake CPUs would have made the Core i7-7700K, at around £300, the cheap­est Core i7 ‘K’ CPU the com­pany has ever pro­duced. It was low enough that we mapped out the price of the chip in a chart and was pre­pared to write that the CPU price war had al­ready be­gun with AMD over its up­com­ing Ryzen.

Alas, it was all wrong. In­tel up­dated its price sheets, in­creas­ing the cost to £339. That’s the same price as the Haswell, Devil’s Canyon, and Sky­lake Core i7 pro­ces­sors launched at.

In de­fence of In­tel, ev­ery new chip in the price list went up by around £30 to £60. Even lap­top CPUs, where In­tel es­sen­tially has no com­pe­ti­tion from AMD to­day, in­creased. So maybe this was truly just an across-the- Ex­cel formula er­ror and not a rea­son that’s spelled Ryzen. Clearly, though, the price war with AMD isn’t kick­ing off with Kaby Lake.

Con­clu­sion

Run­ning at 5GHz, the Kaby Lake will match a six-core Ivy Bridge-E in per­for­mance. In sin­gle-threaded ap­pli­ca­tions at 5GHz, the re­sults are even more im­pres­sive

So let’s sum it up. In lap­tops, the per­for­mance bump is very de­cent, with per­haps 20 per­cent or more go­ing from just Broad­well to Kaby Lake.

Desk­tops aren’t con­strained by ther­mals and bat­tery life the way lap­tops are, so the per­for­mance dif­fer­ence be­tween the gen­er­a­tions is far less. The one re­ally big dif­fer­ence be­tween pre­vi­ous chips is the greatly im­proved video en­gine. To per­for­mance-ori­ented desk­top users, though, in­te­grated graph­ics – out­side of NUC-style mini-PCs – is unim­por­tant.

The price, though equal to Sky­lake, is a lit­tle dis­ap­point­ing for those who ex­pected it to be cheaper, but it’s not like you’re

pay­ing more for less per­for­mance. In­stead, you’re pay­ing the same price to get a lit­tle bet­ter per­for­mance. Kaby Lake is bet­ter and faster, but de­spite the greater over­clock­ing po­ten­tial, you can see why, for most DIYers, it’s a lit­tle bit of a yawn. Still, some builders should con­sider it, and we break down the de­ci­sion tree CPU by CPU right here.

If we had a Core i7-6700K sys­tem: We wouldn’t up­grade to Kaby Lake, and we don’t think In­tel ex­pects you to un­less you want to help prop up its bot­tom line. There’s just ab­so­lutely noth­ing com­pelling that would war­rant it on a dis­crete graph­ics sys­tem right now. If In­tel’s Op­tane emerges as a game changer, then you’d con­sider a move.

If we were go­ing to build a new Core i76700K sys­tem: We wouldn’t. In­stead, we’d build one us­ing the new Core 7-7700K. Even if you don’t in­tend to over­clock it at first, the stock clock is al­ready higher, and prices will be the same once ini­tial de­mand set­tles down. The sim­ple an­swer is Kaby Lake is bet­ter, so there’s no rea­son to buy Sky­lake.

If we had a Core i7-4770K or Core i7-4790K sys­tem: We prob­a­bly wouldn’t up­grade. The Core i7-4770K is still a pow­er­ful and use­ful CPU. The only rea­son would be the need for more M.2 or U.2 stor­age op­tions, or if you want to be ready for Op­tane.

If we had a Core i7-4960X or Core i7-3960X sys­tem: Even a once mighty six-core CPU can now be matched by In­tel’s new Core i7-7700K in some work­loads. How­ever, if you were the kind of per­son who bought a six-core Sandy Bridge-E or Ivy Bridge-E, you care about core count for a rea­son. It makes far more sense to buy into In­tel’s Broad­well-E plat­form to run a six-core or eight-core CPU. Or just wait to see if AMD’s Ryzen can give you the core counts and per­for­mance you need.

If we had a Core i7-3770K or Core i72600K: Look, there’s noth­ing wrong with the clas­sic Core i7-3770K or Core i7-2600K in ac­tual CPU per­for­mance. The prob­lem is your chipset. The Z77 chipset only has two SATA 6Gb/s ports, and good luck try­ing to run a mod­ern M.2 NVMe drive in them. Th­ese plat­forms are about as creaky as a Austin Mae­stro with 275,000 miles on the milome­ter and a leaky gear­box. It’s ba­si­cally time to up­grade, and Kaby Lake would be fine for both.

If we had a Core i5: You can get by with a quad-core with­out Hy­per-Thread­ing, but anec­do­tal re­ports say the days of a quad­core only CPU are draw­ing to a close. And if you have to up­grade your Sandy Bridge or Ivy Bridge Core i5 chip (or even Haswell or Sky­lake), it prob­a­bly makes sense to up­grade all the way to a new Kaby Lake CPU.

If we had an AMD FX-9590: Well yes, an up­grade to Kaby Lake for your AMD ‘eight­core’ would be very nice. But let’s face it, there’s a rea­son you’re rolling one of AMD’s top CPUs – you’re an AMD fan. Just wait to see if AMD’s Ryzen ma­te­ri­al­izes and of­fers the price-to-per­for­mance ra­tio peo­ple are hop­ing for, so you can con­tinue to fly the white, black and green flag. If Ryzen does fal­ter out of the gate (un­likely), then, yes, a shiny Kaby Lake might be in your fu­ture.

Kaby Lake is the first K chip in sev­eral gen­er­a­tions that seems able to hit 5GHz

Kaby Lake gets the sev­enth-gen­er­a­tion name be­cause of the im­proved graph­ics core and video en­gine, while the x86 cores are es­sen­tially un­changed

The Z170 chipset was a big step for­ward for main­stream mother­board chipsets, and the Z270 inches it a lit­tle bit far­ther for­ward

The Z270 is the first ‘Op­tane-ready’ chipset from In­tel. We just don’t know what ex­actly that means yet

From left to right: an 8-core Core i7-5960X, the new Core i7-7700K, the an­cient Core i7-2600K, and a Core i7-4790K

Cinebench R15 puts the new Core i7-7700K at the top of the heap for main­stream quad-core chips

POV Ray mostly matches our re­sults from Cinebench R15. The Kaby Lake chip eases out in front of the Sky­lake chip, but it’s not a game changer

Just like with Cinebench, when you run on a sin­gle core, the higher fre­quency chips win

Blender 2.77a is a free ren­der ap­pli­ca­tion pop­u­lar with in­die film­mak­ers

In an ac­tual game, most of your div­i­dends still come from the graph­ics chip once you have a de­cently pow­ered quad-core chip

When it comes to physics there is an ad­van­tage, but most gam­ing is still pri­mar­ily a graph­ics task

The CPU still plays very lit­tle role in most graph­ics chores

Asus said its new Z270 moth­er­boards should be able to over­clock In­tel’s new with an 80 per­cent suc­cess rate

The rear of a Kaby lake CPU

Clock speeds, core count, and process keeps per­for­mance mov­ing along

With all five CPUs locked at 2.5GHz, you can see that the ef­fi­ciency of each has only slowly in­creased

A Kaby Lake run­ning at 5GHz in sin­gle-threaded tasks will be tough to beat

The ini­tial price of the Core i7-7700K we were given would have been the cheap­est Core i7 ‘K’ CPU in his­tory. Un­for­tu­nately, that turned out to be wrong

Kaby Lake is a drop-in re­place­ment for Sky­lake. I’m just not sure any­one should or would do that

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