The Intel Lakefield Deep Dive: Everything To Know About the First x86 Hybrid CPU
by Dr. Ian Cutress on July 2, 2020 9:00 AM ESTPerformance Numbers: How To Interpret Them
On the previous page, we covered all three of the initial Lakefield designs. All three are very premium products, either offering a super light and thin clamshell with the Samsung, a foldable display with the Lenovo, or dual 9-inch displays in the case of the Microsoft device. Typically we see these sorts of devices paired with the best-in-class performance hardware, which can cost a lot depending on where it is coming from. Add in the device material cost, and we can easily go north of $999, $1499, or even higher when paired with lots of storage, or items like variable refresh displays. Make no mistake, Lakefield will end up in premium high-cost products.
This means that there will be a certain expectation of performance. Users won’t be satisfied if they get an expensive product with mid-range performance – if they’ve paid top dollar, they want it to exceed in all areas. Performance, battery life, and aesthetics all matter to the end-user when we’re dealing with things like flexible displays or new and exciting form factors on top of everything else.
Now don’t get us wrong here, Lakefield certainly fits many of the criterion of a premium product. It was specifically designed to fit into a small footprint by using novel and complex technology. By using the die-to-die bonding techniques and PoP memory, Intel has put in 174 mm2 of silicon into 12mmx12mm dimensions at only 1mm z-height. It leverages both Intel’s leading edge 10+ manufacturing node as well as Intel’s 22FFL high efficiency manufacturing node, and then optimized layout and manufacturing to ensure it has the most appropriate thermal characteristics for the design. There’s also the ultra-low idle power, supposedly measuring 2-3 mW, which has been an important characteristic in laptops that have been using smartphone processors. Offering substantial idle battery life is a key to marketing this type of product.
However, this page is about performance. Ultimately Lakefield can be compared to a number of products on the market. Numbers in brackets indicate big cores and small cores:
- Intel 7 W Lakefield (1+4) vs Qualcomm Snapdragon 7c (0+8)
- Intel 7 W Lakefield (1+4) vs Intel 6 W Goldmont+ Atom (0+4) N5030
- Intel 7 W Lakefield (1+4) vs Intel 5 W Amber Lake-Y (2+0) m3-8100Y
- Intel 7 W Lakefield (1+4) vs Intel 9 W Ice Lake-Y (2+0) 1005G1
Comparison Table for Lakefield | |||||
Intel i7-L16G7 |
AnandTech | Intel i3-1005G1 |
Intel m3-8100Y |
Intel N5030 |
Qualcomm SD 7c |
Lakefield | SoC | Ice Lake-Y |
Amber Lake-Y |
Goldmont+ | Kryo |
1+4 | Core Config | 2+0 | 2+0 | 0+4 | 0+8 |
7 W | TDP | 9 W | 5 W | 6 W | ~7 W |
1 x SNC 4 x TNT |
CPU | 2 x SNC | 2 x SKL | 4 x GMN+ | 8 x Kryo |
Gen 11 64 EUs 0.5 GHz |
GPU | Gen 11 32 EUs 0.9 GHz |
Gen 9 24 EUs 0.9 GHz |
Gen 9 18 EUs 750 MHz |
Adreno 618 |
4267 | LPDDR | 3733 | LPD3-1866 | 2400 | 4267 |
Wi-Fi 6* | Wi-Fi | Wi-Fi 5* | - | - | Wi-Fi 6 |
- | Modem | - | - | - | Cat15/13 |
One processor I missed out here is the Qualcomm Snapdragon 8cx, which is a 4+4 configuration that Qualcomm has specifically built for these sorts of mobile devices. The 4+4 configuration, on paper, might seem unfair to the 1+4 of Lakefield, whereas the 0+8 configuratrion of the Snapdragon 7c is more in line with what we might expect. However, the Snapdragon 7c isn’t actually inside any retail devices right now, having only been on display at Qualcomm’s own event in December.
The thing is, the Snapdragon 7c is set to be in devices competing at the $500 level against entry-level Intel Celeron devices. The 8cx is the premium chip, that ends up in the premium devices. This is where Intel will have difficulty.
On Intel’s own slides, the company performs two main comparisons.
- Benchmarks against Amber Lake-Y, the i7-8500Y in 5W mode
- Benchmarks where the i5-L16G7 runs in 1+4 and 0+4 modes
Benchmarks vs. Intel Amber Lake i7-8500Y
For the first point, Intel promotes the following against Amber Lake:
- +12% single threaded performance, measured by SPEC2006 (3.0 GHz vs 4.2 GHz)
- +70% graphics performance, 3DMark11 comparing HD615 (24 EUs, Gen 9.5 at 1.05 GHz, 2x4 GB LPDDR3-1866) vs HD (64 EUs, Gen11 at 500 MHz, 2x4 GB LPDDR4X-4267)
- +24% power efficiency, score per Watt on WebXPRT 3
- +100% AI workloads on graphics, ResNet50 batch 128 on OpenVINO, comparing
For each of these workloads, there’s something very obvious to pick at.
The first one is SPEC2006, not SPEC2017, and it’s comparing an Amber Lake core to a Sunny Cove core, which as we discussed should have +18% IPC. The frequency difference (assuming both were allowed to turbo to max) is 40% in the favor of Amber Lake, however the Lakefield has a 40% TDP advantage.
On the graphics performance, it’s a substantial mashup – Gen 9 vs Gen 11, 24 EUs vs 64 EUs, 1.05 GHz vs 500 MHz, LPDDR3-1866 vs LPDDR4X-4267. We know that Intel is going wide and slow with Lakefield, and the fact that Lakefield has an additional 40% TDP to help the graphics and CPU cores, I suspect that each chip was battling to find the right balance of power to the CPU or power to the GPU.
On the AI workload, this benchmark has been hand-picked. Intel has done an offline Resnet-50, and run the CPUs in batches. With the GPU being wide and slow, there is the question as to whether the GPU would be competitive in batch-1 type scenarios. Again, there’s also a TDP difference here, as well as a memory difference that explains the raw performance change.
Benchmarks Against Lakefield in 1+4 Mode against 0+4 Mode
For the second set of benchmarks, Intel promotes +33% higher web performance and 17% better power efficiency by adding a big core to a quartet of small cores – essentially comparing a full fat Lakefield against a quad-core Atom design.
What this means is that Lakefield, by and large, will perform the same as a quad-core Atom in almost all tasks, especially heavy tasks. Given that we haven’t had a new Atom platform since 2017, and it’s been even longer since we saw Atom notebooks in a big way, I can guarantee that a lot of users will look at Lakefield and compare it to big-core designs. Intel has also tripped over its own feet in not comparing the performance to any of Qualcomm’s designs. The cost would seem to put it square against the Snapdragon 8cx, however the core layout suggests the 7c would be a fairer fight. Putting Intel’s AI test against Qualcomm’s hardware would also make for an interesting comparison.
Another thing to note, which Intel glossed over, that most people are going to be really concerned about.
What The Big Core Is Actually For
I’ve mentioned a few times in this piece that the big Sunny Cove core is more for end-user latency driven interactions, such as tapping on the screen, typing on the keyboard. When it comes to loading a web page, this blurs the line between response and workload, depending on the browser and how it manages threads.
Now, if we take a traditional high load single threaded workload, such as say, rendering. Which core will it run on? A lot of Intel’s marketing materials, as well as considering the layout of the chip, might get a reasonable end-user to expect that it would run on the high-performance single core. However, consider two things: firstly, rendering a frame is not a latency-driven interaction. Secondly, how many processes are running in the background? Both of these elements would point to the operating system pushing the workload, despite being single threaded, onto the Tremont Atom cores.
At the time of writing, Notebookcheck is the only outlet to publish data from an early look on Samsung’s Galaxy Book S. If we take a single threaded rendering workload, like Cinebench R15, then Lakefield scores 88 points, while the Amber Lake that Intel used in its slides scores 129, a +46% performance uplift to the older Amber Lake system. What in the world is going on? It’s running on the Atom cores.
Our recommendation, for anyone wanting to test the performance of that single Sunny Cove core, is to implement an affinity mask on the software being used. If the software only knows that one core exists, then it can only run on that core. This is how we suspect that Intel achieved the single core performance gains in benchmarks like SPEC2006. However Intel has more tools at its disposal – there’s a chance that the scheduler for these systems might ignore affinity masks in order to maintain a thermal balance in the design. We must wait until we get a sample in for ourselves.
To a certain extent we see this in the Cinebench R15 multi-threaded test. With a standard 5 thread processor, if you run a standard nT test, we expect it to fill all the cores to give the best performance. In Notebookcheck’s article, we can see that the scheduler has evicted the workload from the big core. This is likely due to power/thermal hotspot reasons.
Source: Notebookcheck
In the task manager on the right, we see the first four Atom cores running at 100% while in the multi-threaded test, while the large Sunny Cove core is relatively idle. Note that the CPU is running at 1.9 GHz, and not the 2.8 GHz that Intel has promoted is the all-core turbo for this product.
But the bottom line is that in most cases, expect Lakefield to perform similar to four Atom cores, just above Goldmont Plus, and not like any of the Skylake/Ice Lake Core products and its derivatives.
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Drkrieger01 - Friday, July 3, 2020 - link
I'm not one to criticize, but this comment section is a dumpster fire.First of all, this is a FIRST GENERATION PRODUCT that hasn't even/barely made it to market.
Secondly, no one has really gotten to do a deep dive on performance of said product.
Thirdly, this processor package can be used from low end laptops, to tablets, and possibly it other mobile devices.
Fourth - who the hell cares about AVX? Do you people realize just how little AVX-512 is actually used in day-to-day usage scenarios that this CPU would be designed for? (mobile)
How about we wait to see what this product actually does for the technology market before we write it off as 'Intel Trash'.
/drops mic
Wilco1 - Friday, July 3, 2020 - link
What hasn't helped is that both Lakefield and Tremont have been hyped up for some time, so expectations were high. Some sites even claim that Tremont is a Cortex-A77 class core purely based on it having 2x3 decoders... That is setting things up for disappointment and failure."Wait for the next generation, it'll be great" has been used on every Atom, but it never lived up to its promise.
Deicidium369 - Sunday, July 5, 2020 - link
"Wait for the next generation, it'll be great" has been used on every AMD product, but it never lived up to its promise."Wilco1 - Sunday, July 5, 2020 - link
Without a doubt AMD has a much better track record than Intel - where are the 10nm desktops and servers? And Lakefield getting 60% of performance of the 18 month old 8cx is embarassing...lmcd - Sunday, July 5, 2020 - link
Track record is more than the last calendar year in a single market segment. You're kidding yourself if the company that brought Bulldozer, Piledriver, Steamroller, and Excavator to market promising that this was the one that fixed the architecture suddenly gets a pass on everything.Korguz - Monday, July 6, 2020 - link
and yet, it seems intel gets a pass when they make mistakes, or screw up. go figure.Spunjji - Monday, July 6, 2020 - link
Do you want to produce a similar list for the Pentium 4, Itanium, and Atom product ranges, or would that require a little too much intellectual honesty?Both companies have extended periods of bad products. Only one of them had the excuse of mediocre revenues, and only one of them was punished for their repeated failures with a dramatic loss in market share. Tells you a lot, really.
Spunjji - Monday, July 6, 2020 - link
Weird - pretty sure Athlon 64 was a rout, the first Athlon X2 was a rout, and Ryzen 3000 was a rout... You post some of the most asinine crap in this comment section when you're bagging on AMD, which is a real shame, because the rest of the time you seem to make a fair bit of sense.abufrejoval - Friday, July 3, 2020 - link
The entire article is about explaining what can already be inferred from the information we have at hand.Chips are engineering and physics, very little magic and a great degree of predictability.
None of the elements here are first generation, only their combination is a bit new. Ice Lake can be measured, you can benchmark a single core at 5 Watts with ThrottleStop and pinning the benchmark to a single core in any IceLake system. Atoms are well known and we can be sure that when Intel claims 23% improvement at the same power, it won't be 230%.
You can predict it's going to be much more expensive to make than a normal Atom, and you can measure that a single Core CPU below 5 Watts doesn't have a lot of horse power, while multiple cores on this design leave no Wattage for the big one.
This chip will be very expensive to make, so it won't sell at Atom prices. All the engineering is about making small enough to compete with ARM designs, yet capable of competing at 5Watts.
Yes, Ian could still be wrong here and there, but there isn't a lot of room to err.
The rest of us agree, that this chip will fail to make Intel rich and customers happy.
If we should be all wrong, remind us and we'll show proper contrition and learn.
But we bet on what we extrapolate from what we can know and measure, that's our duty as engineers.
lmcd - Sunday, July 5, 2020 - link
Tremont is absolutely new and the thermal characteristics of the package and layout also determine a lot.