The Intel Core i7-6700K Review - Skylake First for Enthusiasts

The Intel Skylake architecture has been on our radar for quite a long time as Intel's next big step in CPU design. Through leaks and some official information discussed by Intel over the past few months, we know at least a handful of details: DDR4 memory support, 14nm process technology, modest IPC gains and impressive GPU improvements. But the details have remained a mystery on how the "tock" of Skylake on the 14nm process technology will differ from Broadwell and Haswell.

Interestingly, due to some shifts in how Intel is releasing Skylake, we are going to be doing a review today with very little information on the Skylake architecture and design (at least officially). While we are very used to the company releasing new information at the Intel Developer Forum along with the launch of a new product, Intel has instead decided to time the release of the first Skylake products with Gamescom in Cologne, Germany. Parts will go on sale today (August 5th) and we are reviewing a new Intel processor without the background knowledge and details that will be needed to really explain any of the changes or differences in performance that we see. It's an odd move honestly, but it has some great repercussions for the enthusiasts that read PC Perspective: Skylake will launch first as an enthusiast-class product for gamers and DIY builders.

For many of you this won't change anything. If you are curious about the performance of the new Core i7-6700K, power consumption, clock for clock IPC improvements and anything else that is measurable, then you'll get exactly what you want from today's article. If you are a gear-head that is looking for more granular details on how the inner-workings of Skylake function, you'll have to wait a couple of weeks longer - Intel plans to release that information on August 18th during IDF.

So what does the addition of DDR4 memory, full range base clock manipulation and a 4.0 GHz base clock on a brand new 14nm architecture mean for users of current Intel or AMD platforms? Also, is it FINALLY time for users of the Core i7-2600K or older systems to push that upgrade button? (Let's hope so!)

[RetroHamer]

Guess I'm sticking to my 2600K for another year or so

[champmav]

Finally time to retire my i7 860. But the expense!! New everything!  It served me well these past six years. RIP.

[bobjames]

I think it's safe to assume moores law is pretty much dead now.

[mr.ihabissa]

Core i7-6700K & Core i5-6600K and Later with the "C" Variant (Locked Multiplier)

Haswell introduced a second way to adjust the clock frequency of a K-series CPU: by changing the base clock (BCLK). Normally this value is 100MHz, but Haswell offered a number of preset straps: 100MHz, 125MHz and 166MHz. Skylake goes further, allowing you to alter it with fractional increments: setting the base clock to 112.5MHz with a 40x multiplier results in a CPU speed of 4.5GHz, for example. This will be a welcome feature for overclockers and high-performance enthusiasts looking to get the most out of their chips.

The biggest change with Sunrise Point is the introduction of PCI Express 3.0 support, with 20 lanes (on the Z170) each running at 8 GT/sec, which provides a lot more bandwidth for PCIe storage devices. An M.2 solid-state drive such as the Kingston Hyper X Predator or Samsung SM951 connected to a Z170 motherboard has four dedicated PCIe 3.0 lanes, which means it has up to 32Gbps of bandwidth. This is a great improvement over both 6Gbps SATA and M.2 on Z97 motherboards, which was limited to just two PCI Express 2.0 lanes. (A welcome improvement, but there are very few M.2 devices currently for sale - and still none M2 SSDs worth an upgrade )

Intel has placed more and more emphasis on integrated graphics, and Skylake is no different. The integrated GPU that comes with Skylake is called Intel HD Graphics 530, and is DirectX 12 compatible. The GPU's clock speed boosts to 1150MHz, and some models (not the HD 530) will likely include a quantity of embedded DRAM (eDRAM). Intel isn't yet talking about the new GPU's architecture in detail, so we can't offer any more specifics at this point; specifics will probably come on August 18 at IDF. But on't expect Intel HD Graphics 530 (or the inevitable "Iris" version) to allow you to play modern 1080p games at ultra detail levels, but 720p on high or medium details ought to be possible. (A welcome improvement, but strictly for people who want to spend money on a card like 750Ti which is a good replacement)

Skylake processors hasn’t changed is the number of PCI Express 3.0 lanes, which is still set at 16. This allows for a single PCIe graphics card to operate at x16 speeds, or a pair in SLI or CrossFire to operate at x8. For more graphics lanes, you’ll need a Haswell-E processor (the top-end 5960X has a grand total of 40 PCIe lanes)—although moving to the X99 chipset is of questionable value if it’s just for SLI or CrossFire use. (A downside)

Performance Increase of I7 -6700 K over the I7 4970 K both at 4.0 Ghz - Around 10% (General Bench marking) if any. With a greatly increased clock speed over DDR3, the addition of faster DDR4 memory is partly responsible for some of Skylake’s improved benchmark results mainly in Geekbench 3 .While in gaming: The move from Haswell to Skylake made little difference, Frame rates hovered around the same point, whether at 1080p or 1440p resolution, and regardless of the detail setting. (DDR4 are yet to be fully realized, and no major increase from DDR3 on the other hand gaming performance is not a changer in Skylake)

Skylake appearing to have better overclocking headroom than Haswell, this could potentially be a interesting chip for overclockers. It can tips 4.8 Ghz stable.

Worth an Upgrade? Maybe if you are an owner Core i7-2600K; Skylake can be a "tempting" option - Otherwise, while the new additions to the chipset are definitely a move in the right direction, there are very few M.2 devices currently for sale, USB 3.1 is still in its infancy, and some of the advantages of DDR4 are yet to be fully realized. Waiting a year or two for these nascent technologies to mature might not be a bad idea. Skylake isn't the only viable option right now: the six-core Haswell-E Core i7-5820K, which is priced very similarly to the 6700K, is a very strong performer indeed.

[ShadeWMD]

I'm still rocking an i5 2500k and wouldn't have considered upgrading to a 6700k just for standard gaming, but VR is coming this holiday and my kids want a new PC so I'm in a strange place. I'm going to upgrade to Skylake, but only because I'm not waiting a year and a half for VR. I'm getting the Vive and Rift as soon as they come out in a few months.

I'll upgrade again in a few years and throw in a Pascal GPU in my Skylake build when they drop next year.

[TeslaRifle]

Been running a Phenom 955 and 560 Ti for years. Was holding off upgrading since finishing college this spring, to see how this release went. With Fallout4 coming out am def upgrading to Skylake and a 980 this fall.

[Soldier-ziwg]

Thanks for the review, on the ropes about upgrading my 2600k at 4.5. Especially since Win 10 just nearly doubled my gaming fps coming from Win 7 alone. Still using a 780 classified too.

[pedjakrcedinac]

How is the pricing aggressive!? They went from 45nm i7-860 to 14nm, never increased core count, and you have to pay 80$ more. And they are selling you the iGPU which no-one who buys these doesn't need. Sale margin must be 300%. Man, Zen can't come soon enough never to see intel's CPU again.

[Voidward]

Yeah, totally plan on upgrading my 2500k with this.

Was hopeful about the rumours of it being able to OC to 5ghz+, but still a very solid upgrade at similar clock speeds. Also felt the need the bump up my 8gb of DDR to 16, so looks like it's all gonna happen at the same time.

[bobjames]

"At $350 i still think it is a very competitive part." What is it even competing with? it barely even beats intel's last gen part at a higher price. And this has been the same for about 5 years now. Where is the outrage?

[addictedtopiano]

Would've liked to hear about the improved efficiency and performance to watt ratio as well.

[Bannockburn]

Good to see you compare over several generations.

Some people complain about smaller increases in CPU capabilities, but that only really matters if you want to upgrade every generation. A 5% increase over 4 gens is a  21.5 %increase from the earliest. That is significant and will improve the user's experience.

DDR4 - I'm not at all interested in it until the products mature enough that we see the top end of the spec at more or less reasonable prices. There just isn't enough benefit right now.

[jowarnis]

I5 - 6600k will probably be new best choice for gamers if the price is similar to i5 4690k

[DemonizedTX]

I actually run a core i7-920 and it's finally time to upgrade.

[rapper]

The Skylake i7 from 2015 (this year) is only 21% better in IPC per thread than the sandy bridge i7 from 2011. a 21% improvement in 4 years does NOT go with moores law AT ALL. This is what happens when you have little competition in any industry. Look at local cable companies and how they charge obscenely.

[georgemagdaleno]

Watched this again this morning and I still feel conflicted about upgrading to Kaby Lake 7700K may just wait for a fire sale on 6700K parts.

[drakeowens]

I problem I see with Skylake is the low number of PCIe lanes. As a gamer I run two graphics cards in SLI which is becoming very common with gamers. That uses up sixteen PCIe lanes. If I decide to upgrade to a PCIe SSD that uses the remaining four lanes and I can no longer use the USB 3.1 or M2 ports which use PCIe lanes. The fact is that PCIe has become the bus of choice for more and more devices and Skylake's twenty lanes just isn't enough.

[ChronoVersatur]

@Ryan. In your upcoming tests, can you make sure you test an i7 920/930 at 4ghz against a Skylake at stock and oc'd. Testing i7 920 at stock won't tell much as most run them overclocked. Thanks.

[delatroy]

14nm baby. Hard to believe it's here! Now please release 14nm 8 core variant :}

[chazzychaz]

every 1/1.5 year we only saw 5~12% improvement on the CPU
damn... this is ridiculously slow ~ 

for gaming wise, I really dont see the need to remove my i5 3570k for now
and DDR4 is kinda expensive now