Rumor: Intel to Follow Up Skylake with Kaby Lake
Tick Tock Tick Tock Tick Tock Tock
A few websites have been re-reporting on a leak from BenchLife.info about Kaby Lake, which is supposedly a second 14nm redesign (“Tock”) to be injected between Skylake and Cannonlake.
UPDATE (July 2nd, 3:20pm ET): It has been pointed out that many hoaxes have come out of the same source, and that I should be more clear in my disclaimer. This is an unconfirmed, relatively easy to fake leak that does not have a second, independent source. I reported on it because (apart from being interesting enough) some details were listed on the images, but not highlighted in the leak, such as "GT0" and a lack of Iris Pro on -K. That suggests that the leaker got the images from somewhere, but didn't notice those details, which implies that the original source was hoaxed by an anonymous source, who only seeded the hoax to a single media outlet, or that it was an actual leak.
Either way, enjoy my analysis but realize that this is a single, unconfirmed source who allegedly published hoaxes in the past.
Image Credit: BenchLife.info
If true, this would be a major shift in both Intel's current roadmap as well as how they justify their research strategies. It also includes a rough stack of product categories, from 4.5W up to 91W TDPs, including their planned integrated graphics configurations. This leads to a pair of interesting stories:
How Kaby Lake could affect Intel's processors going forward. Since 2006, Intel has only budgeted a single CPU architecture redesign for any given fabrication process node. Taking two attempts on the 14nm process buys time for 10nm to become viable, but it could also give them more time to build up a better library of circuit elements, allowing them to assemble better processors in the future.
What type of user will be given Iris Pro? Also, will graphics-free options be available in the sub-Enthusiast class? When buying a processor from Intel, the high-end mainstream processors tend to have GT2-class graphics, such as the Intel HD 4600. Enthusiast architectures, such as Haswell-E, cannot be used without discrete graphics -- the extra space is used for more cores, I/O lanes, or other features. As we will discuss later, Broadwell took a step into changing the availability of Iris Pro in the high-end mainstream, but it doesn't seem like Kaby Lake will make any more progress. Also, if I am interpreting the table correctly, Kaby Lake might bring iGPU-less CPUs to LGA 1151.
Keeping Your Core Regular
To the first point, Intel has been on a steady tick-tock cycle since the Pentium 4 architecture reached the 65nm process node, which was a “tick”. The “tock” came from the Conroe/Merom architecture that was branded “Core 2”. This new architecture was a severe departure from the high clock, relatively low IPC design that Netburst was built around, which instantaneously changed the processor landscape from a dominant AMD to an Intel runaway lead.
After 65nm and Core 2 started the cycle, every new architecture alternated between shrinking the existing architecture to smaller transistors (tick) and creating a new design on the same fabrication process (tock). Even though Intel has been steadily increasing their R&D budget over time, which is now in the range of $10 to $12 billion USD each year, creating smaller, more intricate designs with new process nodes has been getting harder. For comparison, AMD's total revenue (not just profits) for 2014 was $5.51 billion USD.
As I have said before, developing integrated circuits is like a game. You are given a budget in complexity and you need to create an architecture that completes the most tasks within those constraints. If you can add more features within the same die area, you can afford to add more logic. Smaller transistors also take less power, which increases that budget for chip designers.
But you cannot redesign everything, every time. That's too much work.
With Intel's release structure, they separate the benefits of better designs and smaller features into alternating products. This allows them to allocate resources on a regular pattern, which probably smooths out their research and development budget by keeping the problems that their engineers need to solve constant and steady. Broadwell, which brought the Haswell architecture to 14nm, was painful though. The release was delayed so severely that just a few products were launched to end-users. Apart from Core M, even device manufacturers will not have too many Broadwell options before the launch of Skylake in a couple of months, at least compared to what we are used to from Intel. The couple of Broadwell parts that are designed for the LGA, user-swappable socket that we received were lower performance than the top-end Haswell SKUs that preceeded it. It was like they just released them to satisfy their promise of Iris Pro for customers looking to upgrade Haswell-based systems, even though they wouldn't really be upgrades, outside of graphics, in many cases.
Skylake was supposed to take 14nm, brought in by Broadwell, which shrunk Haswell, and create a new architecture that Cannonlake will shrink to 10nm in 2016. Tick. Tock. It now looks like 10nm will be delayed, and we will not just get a Skylake refresh in 2016. Rather, the rumor claims that Intel is planning to inject a new architecture, Kaby Lake, in the gap. What the rumor does not say, however, is how far Kaby Lake will diverge from Skylake.
This is technically a Xeon Phi core, but you know.
What this does provide is an extra release cycle for Intel to rethink their existing circuit elements, which could provide a better vocabulary for them to use later. This time might not be wasted. In the areas that are usually copied blindly from previous architectures, the engineers can inspect whether they are showing their age. Given the chance, engineers will find subtle ways to make existing solutions better. An optimist would look at this situation and focus on the light being cast into the dark corners of previous designs, rather than just doing a two-refresh lifecycle for Skylake.
A pessimist would note that Intel always could have focused on architecture. Smaller fabs were better.
Considering both views, the result is that time, measured in product iterations, is not being wasted. The research done on Kaby Lake, whether vast or miniscule, could help Intel in the long run. Whatever they do better now, will be done better forever. What it might not do is bring Intel as far forward as they would be had they been given a healthy and on schedule transition to 10nm and beyond. Would have, could have, should have.
Good Graphics... I Said Good Graphics!
Like the current stack, Kaby Lake will be available in Y, U, H, and S suffixes.
Repeated for relevance. Image Credit: BenchLife.info
The -Y series will service products at 4.5W with dual-core parts. The -U series will handle the range from 15W to 28W with dual-core solutions, which is popular for mid-range laptops and X-in-one devices. The -H series has TDPs of 35W, 45W, and a “TBD” class, with each product having four cores. "H" products are probably intended for higher-end Ultrabooks. These three suffixes should all be BGA-based, which needs to be soldered to the motherboard and thus mass-produced devices.
The -S suffix will handle user-replaceable components with the LGA-1151 socket. They will be available in TDPs of 25, 35, 45, 65, 80, and 91 watts. Most Kaby Lake-S processors will be quad-core, but dual-core options will be available at the low end. Since they use the same socket as Skylake and what we believe Cannonlake will use, it might be possible to upgrade the CPU across all three generations... might. If so, this would be Intel's largest upgrade path in the last decade (counting by architectures).
In terms of graphics, almost every S-class processor will be paired with GT2, with two exceptions.
Image Credit: Anandtech
At 35W and 65W, GT4 graphics will
be available on Kaby Lake-S (Update - July 2nd, 3:40pm: Missed the footnote stating that Iris Pro for -S SKUs will be based on Skylake) with 64MB of eDRAM, which is better known as Iris Pro. Like the recent Broadwell release on LGA-1150, this will allow enthusiasts to build desktops with Iris Pro graphics, which could be useful for home theater PCs that cannot afford a discrete graphics solution for one reason or another. Users who want the best CPU performance will not get Iris Pro, however. This is a bit disappointing, particularly with DirectX 12 and Explicit Unlinked Multiadapter soon taking advantage of the on-chip GPU. With Broadwell on LGA-1150, the lack of high-performance Iris Pro could be written off as Intel not really caring. The trend persisting through Kaby Lake, and we assume Skylake too, shows it as much more deliberate.
Hopefully Intel will at least give options when an on-processor GPU has practical advantages over discrete GPUs. Tasks, like AI path-finding and visibility, could be shredded by a GPU, but the latency of getting the task to an add-in graphics card and back again negates this, even if the software developer could afford the effort. On-processor GPUs are promising for these tasks, but less so if high-performance graphics is only available to a sliver of users that are sort of high end, but not high-end.
And then we get to the other exception...
On the table, there is a row of quad-core processors at 25W, 45W, and 80W that have “GT0” graphics. Since there is no such thing as “GT0” graphics that I know of, and I have not even seen this moniker used before, this might be Intel's way of denoting desktop processors without integrated graphics. As I alluded to in the introduction, I could be misinterpreting the table. If I am not, then we might see 80W TDP processors available from Intel without integrated graphics at all.
80W is below the “high-end” CPUs from Intel at the ~90 watt point, such as Devil's Canyon (88W) and whatever the 91W Kaby Lake processor would be. Still, without needing to account for a GPU, this might have the same performance (or better) as the 91 watt version... or not. It appears as though Intel will not release these 80W CPUs with GT0 unlocked though, as the table only lists the 91W part as being part of the “K” branding. If I had to guess, mainstream enthusiasts will still want the model with the iGPU, even if they don't plan on using it (and DirectX 12 titles don't use it for them). I cannot think of a use case that Intel would be targeting if all this is true.
So there we have it. This was an interesting little leak, which could be totally crap. It sounds reasonable though, because the details mesh together in ways that I doubt a hoax would bother lining up. In many ways, this could be an opportunity for Intel to better position themselves for the future. It takes the place of their regular schedule however, which would imply that whatever they do would be inferior, all things considered, to their original plan succeeding perfectly, since it is by nature a compromise from that.
It may all depend on whether you count 10nm woes as an external factor.