When Intel ushered in its 12th generation Alder Lake laptop and desktop hybrid processors three years ago, it set in motion a process that would redefine how a CPU is designed and also how it works with Windows. Its recent Lunar Lake mobile processor launch is the fourth generation of these CPUs that features two different types of cores and the biggest changes this time around are primarily down to how those cores function as a team.
In what many viewed as a surprising and drastic move, Lunar Lake CPUs do away with a long standing feature called Hyper-Threading, which allows individual cores to handle two software threads instead of one, filling any downtime and improving performance, particularly in multi-threaded workloads. There are rumors it will remove this feature from its Arrow Lake desktop CPUs too, ending two decades of the feature being supported on desktop PCs.
I caught up with David Feng, Vice President and General Manager of Intel’s Client Computing Group at Germany’s IFA event this month and he explained why these hybrid mixes of performance cores (P-cores) and efficient cores (E-cores) mean that including hyper-threading no longer makes sense and can actually result in a negative overall benefit in modern CPUs.
Antony: Lunar Lake is a major launch for Intel and the performance and power efficiency claims are impressive. I was hoping you could maybe explain what the benefits are of upgrading to new laptop would be to owners of say a 10th or 11th Gen laptop would be – something that was new 5 years ago and also from something newer – perhaps bought in the last 12 months?
David: The world is a very different place now. If you have a CPU that is three or four years old, back then we were not running ChatGPTs or AI. Even aside from the changes that Covid brought, we now have a whole new appreciation for performance per watt and power efficiency. Not that we didn’t care back then, but it’s a level of prioritisation. Back then performance was a higher priority but now it’s more balanced with thin and light devices focussing on performance and low power at the same time.
Compared to those older CPUs, you’ll see significantly more performance and much longer battery life. Modern processors can run new classes of applications powered by AI and Lunar Lake is also designed to handle triple-A games all on a thin and light device – something you wouldn’t even be able to imagine four or five years ago unless you had a heavy laptop with a discrete GPU.
Now, moving from the more recent Meteor Lake Core Ultra 100 to Lunar Lake Core Ultra 200 series, you’re most likely something of an earlier adopter or have a high refresh of your technology. Meteor Lake is still a great design and cutting edge in many areas such as AI. However, Lunar Lake still offers significant CPU AI and power efficiency enhancements. That said, Meteor Lake also offers huge benefits compared to 13th Gen CPUs – 30-40% lower power for example. Driving the power down even more than we’ve done before.
When we say Lunar Lake has 30% better GPU performance, we’re actually comparing that to Meteor Lake H which is the higher power segment. Compared to Meteor Lake U-series it’s an even bigger improvement. Probably up to 80% graphics improvement. But even Meteor Lake has far superior graphics performance to earlier models.
Antony: That’s been quite a quick transition from Meteor Lake to Lunar Lake. What’s driven Intel to launch a new generation of CPUs in such a short time frame?
David: That’s a really good question. Silicon has a long lead time in term of designing and bringing a product to market. Usually four or five years. We’re continuously looking at the future architectures on a rolling basis. When planning for the Meteor Lake architecture we recognised the importance of having a new engine like an NPU, new power management like low power E-core and driven by our Foveros 3D packaging to bring everything together. When our architects put our Meteor Lake architecture together they were working towards that timeframe, but with the next generation they could already see ways of enhancing the different cores, the GPU core, the NPU and power management.
For example, we had two E-cores with Meteor Lake and something we realised quickly is that it would be more beneficial to power savings to have more of them with a larger cache too. That’s where Lunar Lake’s 50% power savings come from. We could drive more applications without having to engage the more power hungry P-cores at all. We’re learning as we go with that power and performance balance with our hybrid core designs.
Antony: I’ve been following Intel’s Evo standard ever since it was the unbranded project Athena as I thought it was a great idea – having a standard that makes it easier to pick a laptop that guarantees a quality experience in terms of battery life, performance and features. Has the Evo standard evolved much over time?
David: Again a great question. It hasn’t changed in its goals. It’s still to offer the best, uncompromised mobile experience. The types of applications, though, are evolving. AI for example, wasn’t part of the plan back then. At the very beginning I don’t think we appreciated how much the core components would vary and have such an impact on performance. Screen panels, memory and even SSDs can have big affects on your power profile. With a few generations of Evo now under out belt we learned so much about the system ingredients and variations so we’re now in a much better position to guide the industry on how to put together the best configuration.
From a user experience perspective, since Meteor Lake, we added more testing to balance cool and quiet performance operation. We know how to boost performance but doing that without generating a lot of heat or noise is key, as well as maintaining battery life. So now you have four competing things and we’re learning from Meteor Lake and added testing criteria for cool and quiet operation. That’s one example.
With Lunar Lake, we have an increased focus on gaming and can run triple A games at playable frame rates. I was purposely going around the demo systems here at IFA to touch the back of the laptops with my hand. They were not even warm and they were quiet too. The webcam is something we’ve added recently too. Resolution or pixels are important but they are not always an indication of image quality. We are constantly raising the bar for what is expect for Evo.
Antony:The removal of hyper threading with Lunar Lake is a big move and it’s what’s been rumored with desktop Arrow Lake due later this year too. Won’t this result in less multi-thread performance compared previous generations? What would you say to those concerned about that? Was the reasoning mainly power efficiency related? Hyper threading has obviously been a feature of Intel CPUs for so long.
David: Hyper-threading was a great idea and our engineers figured that when we’re loading the compute pipeline, we’re not fully utilising it because it’s like building a car on a manufacturing pipeline, I want to make sure every station is fully utilized all the time. So when they built the data pipelines and hyper-threading was implemented they were using 100% of pipeline all the time along with a relatively small overhead in terms of power and extra space on the CPU die to get another thread. However, it was more for a desktop market than a mobile market. The expectations for mobile devices were lower back then and not today where we have 20 hour battery life.
When we first introduced hybrid cores – E-Cores and P-cores with out 12th Gen architecture, there were some discussions about whether that was achieving the best battery life and power efficiency. We learned a lot through the generations since Alder Lake and began to understand that actually, a hybrid architecture with E-cores is the most efficient way to deliver the balance between higher performance and including muti-threaded performance and maintaining lower power.
Even with a hybrid architecture you could still have hyper-threading and push forwards some performance metrics but hyper-threading will hit us negatively on power efficiency and power per thread – overall it’s a net neutral or even net negative result which is why Lunar Lake doesn’t support it.
In the past, especially on desktop, this wasn’t much of a concern, but even on desktop enthusiasts are definitely paying more attention to power consumption. The whole industry really is more focussed on a balanced approach to lower level of power for the same performance. For us Lunar Lake is the culmination of everything we’ve learned from previous hybrid core architectures, fully leveraging the benefits of low power E-cores – more of them with more cache – turned out to be a better trade off than maintaining hyper-threading.
I’d like to thank David for taking the time to talk to me about Intel’s major changes to its CPUs. If you’re interested in Lunar Lake laptops, these will be available from the likes of Asus, Dell, LG and MSI on 24th September. Follow me here on Forbes using the blue button below, Facebook or YouTube to get the latest news.
