Intel was pretty lax when it came to the launch of Broadwell on the desktop (literally two months ago), and there hasn’t been much of a push to get those parts out and sent to reviewers or OEMs for testing. Broadwell was genuinely interesting, but the 65W processors that ended up going into the channel weren’t that well priced, or fast enough to justify the extra cost. Intel fixed that on Wednesday this week by launching the Skylake platform (you can read our review of the 6700K by following this handy link), and here’s a brief summary of what you need to know when considering a Skylake build.
Ideally, you’re upgrading from Core 2, Lynnfield, Bloomfield, or Sandy Bridge
Intel’s cadence of recent improvements to the Core architecture meant that jumping from one generation to the next was usually fruitless. The last time we had a performance leap that wasn’t just thanks to IPC improvements and smaller lithography nodes, it was from the Lynnfield and Bloomfield platforms to Sandy Bridge. Performance went up everywhere, 5.0GHz overclocks on air were commonplace, and the platform was just a big step up in every respect. Sandy Bridge just blew everybody away, and it remains one of Intel’s most memorable platforms.
In many cases, enthusiasts who bought a Core i7-2600K on launch day still have almost no reason to upgrade their systems yet. Anyone on a Core i7-920 today doesn’t even have to consider a full replacement – just buy yourself a second-hand Xeon X5650, or one of the faster LGA 1136 Xeons floating about in classifieds sections on the internet. They’re really good.
If you haven’t yet read Neo’s review of the Core i7-6700K yet, here’s the gist of it: If you’re on Ivy Bridge or Haswell, there’s very little difference for most things. Where there have been improvements to the chip, and even to IPC, the effectiveness of such improvements has been lessened by the lower clock speeds out of the box. No, where you’re going to see the biggest performance leap is from a Nehalem or Sandy Bridge-based system, where the improvements can range anywhere from 10% all the way to twice the performance for specific workloads, like encryption or multi-threaded rendering.
If you’re on a Ivy Bridge or Haswell system and want to upgrade to something new now, consider Haswell-E instead. The prices are similar between the Core i7-6700K and the Core i7-5820K, and the extra cores on the Haswell-E processors would be beneficial for multi-tasking and multi-threaded workloads.
Overclocking is a little more involved this time around
Skylake also drops down to the 14 nanometer production process, which means that all the transistors and chip features are bunched closer together. This is good for power-saving designs, because the chip needs less voltage and has a much lower power draw, but if you want it to run really fast, more voltage needs to be pumped through it. Because everything is now more tightly integrated, this means that heat will now collect in a much smaller space, pushing up the temperatures and making the chip unstable at very high frequencies and voltages. Looking at several other reviews on the net, the spread seems to be around an overclock to 4.8GHz with water-cooling at a voltage of 1.4v or thereabouts. Stock voltages are around 1.2v, so that’s a pretty big jump.
The process of overclocking is now also a little simpler, but there’s more scope for control, which means that the time you spend testing out an overclock and finding the limits of a particular chip has increased significantly. Enthusiasts can now increase the BLCK reference clock in 1MHz increments, instead of using the BLCK reference speeds in Haswell and Haswell-E. Because the integrated voltage regulator has been moved back on to the motherboard, we’ll see once more significant differences in the performance of one board to the next in terms of overclocking capabilities, once again opening up the playing field for vendors to figure out how to one-up the other.
There was also a rumour that non-Z Skylake chips would be able to be overclocked when used on a Z170 motherboard, but since there are no non-K chips currently available, we’ll have to wait to see how this one pans out. The last time Intel allowed overclocking of non-K processors was with Ivy Bridge, where you could force a non-K chip to work at its rated boost clock, plus one or two straps higher. On Skylake, non-K overclocking is rumoured to be powered through BLCK tuning.
The Z170 chipset is an overhaul of Z97
Looking at the Z170 chipset, it is pretty familiar, as it follows the standard layout that we’ve had on Intel’s platforms for a while. The chipset gets a pretty hefty bandwidth boost through the DMI interface, which is now operating at PCI Express 3.0 speeds. There are also 20 PCIe 3.0 lanes running out of the chipset for various peripherals and connectivity, which is way, way higher than Z97, which was limited to just eight. What this means for you is more choice, as motherboard vendors will be able to add on more USB ports, more Ethernet controllers, and lots of other goodies to take advantage of this.
Most Z170 boards are now also capable of Crossfire or SLI out of the box, as the 16 PCIe 3.0 lanes running to the CPU are now able to split up three ways. If you so wished, you could set up a graphics card in the first slot running at 8x speeds, while two PCIe SSDs sit in the other slot, running at 4x speeds, and none of that storage has taken up anything on the chipset now. That’s a much more flexible option than before, and Intel has done a good job with offering that to enthusiasts.
Not shown here, but also a new feature, is the ability to RAID two or more M.2 SSDs, or PCIe SSDs, in the BIOS without having to use Windows to configure the setup in software mode, or any of that strange RAID software on most boards today. This is thanks to improvements to Intel’s RST technology, but sadly SATA bottlenecks haven’t yet been addressed. Running four drives in RAID 0 still yields top-end read speeds of around 2.0GB/s, which is just slightly higher than what the Z97 chipset was capable of. Perhaps this will get fixed later, but setting up a six-drive RAID and expecting 3.0GB/s of throughput is not a possibility now.
DDR3L and DDR4 – which one?
Skylake is made to work with DDR3L and DDR4, both low-voltage memory technologies that are optimised for lower power consumption and mobile applications. Intel’s reasoning behind this move was that the server community would benefit tremendously if they only had to upgrade the platform, and not replace all of the expensive ECC-capable buffered DDR3L memory that they bought stacks of. This is also a benefit to rolling out the Skylake mobile processors, because OEMs should be able to deploy it pretty quickly while they wait for DDR4-SODIMM modules to become available for the notebook market.
Still, DDR3 is at its end, and DDR4 will be the way of the future soon. If you’re considering a Skylake build, at a minimum you need to be looking at DDR3-2666MHz. At that point, the frequencies are high enough to see some benefit over DDR3, and latency shouldn’t be too bad either. DDR4-2666 modules also shouldn’t be too expensive compared to 2400MHz either, and its always possible to attempt an overclock to eke out more speed from the chips. In a similar manner to the Nehalem launch, Intel’s warning for Skylake is that voltages above 1.4v for the memory might lead to a life reduction for the memory controller on the chip.
No Iris Pro for this release, yet
Skylake comes with the Intel HD 530 graphics aboard the Core i7-6700K and Core i5-6600K. Officially called “Gen9 GT2” internally, this is not Iris Pro-level graphics, as there’s an obvious lack of L4 cache that would improve the bandwidth numbers tremendously. The HD 530 GPU is about as powerful as the GPU found inside AMD’s A10-7870K APU, though it still lags behind AMD’s integrated graphics performance when it comes to games. The HD 530 has 24 execution units (EU), but Intel doesn’t specify how those are arranged (and they’ll probably only do that when they begin discussing Skylake at IDF 2015). However, there will be a 48 EU version on Skylake processors that will also have eDRAM on the same package, I’m just not sure when that’s going to happen.
In the meantime, if you’re playing on integrated graphics on a Skylake PC, don’t expect to do much better than 720p and medium settings with no anti-aliasing applied, because that’s pretty much the limit of what this chip can do. Some games will be more playable than others, but we’re probably not going to be playing any games on HD 530 for the most part – if you’re a mobile user with a laptop that includes HD 530 graphics, you’ll be happy to know that its not terrible.
Finally, dat price
Of all the more important things that could be discussed when it comes to the Skylake launch, the primary factor that will determine consumer adoption is the price. Today, PC component buyers are incredibly price sensitive, and there’s always a call for cheaper components, or for using hardware which is just “good enough” for most things. This is why Intel’s Core i3 family is still one of their best sellers, and why they decided to launch with the enthusiast-class processors first.
Pricing locally of the chips is pretty steep – easily matching up with Devils Canyon and even Haswell-E. The incentive to use the desktop platform in order to save more money over the HEDT offerings is slowly disappearing. At the same time, less people locally will be willing to swallow the cost associated with the Core i7 brand today, as our Rand continues to get weaker against the US Dollar and UK Pound.
Going by the table here, Skylake processors aren’t priced too badly in comparison to existing solutions, and they’re already available to order through stores like Rebel Tech. While stocks are going to be a bit constrained in the beginning, I’m expecting that by the end of this month there’ll be a healthy flow of Skylake products coming in to the country. Intel’s probably going to be launching the rest of the Core i7, i5, i3 and Pentium processors based on Skylake in the next few months, so there’ll be plenty of changes to look forward to in my System Builder’s Guide.
Motherboards and memory, on the other hand, will be a bit tricky. Finding DDR4-2400 dual-channel kits will still be a little difficult, especially at a good price, although you can find single sticks instead and use those in dual-channel mode. Cooler-wise, LGA1150-compatible coolers will be compatible with the LGA1151 socket, so you won’t have to do much switching around there to make things work. Keep in mind that the Core i5-6600K and the Core i7-6700K are both 95W parts. This is an increase in TDP over Haswell, which means that they will be a bit more difficult to keep cool. Don’t expect to be able to hit 4.8GHz while using a Zalman CNPS10X Optima, or Cooler Master’s Hyper 212X on these chips. You’re restricted to either mammoth air coolers, or water-cooling with 140mm or 240mm attached radiators.
That’s all that we have on Skylake for now. We’ll be keeping an eye on motherboards for these two chips as they become available, and we’ll have a pricing article about those up tomorrow.