5nm / 5LPE: What do we know?

Starting off with the biggest new change of this generation, both the Snapdragon 888 and the Exynos 2100 are manufactured on Samsung’s new 5nm process node, which is the biggest unknown in today’s comparison.

What’s important to remember is that although Samsung calls this node 5nm, its design and characteristics are more similar to that of their 7nm node. Key new characteristics of the new node here are the reintroduction of single diffusion breaks (SDB) on an EUV process node, as well as slight changes in the cell libraries of the process.

Advertised PPA Improvements of New Process Technologies
Data announced by companies during conference calls, press briefings and in press releases
  7LPP
vs 10LPE
6LPP
vs 7LPP
5LPE
vs 7LPP
3GAE
vs 7LPP
Power 50% lower 20% 50%
Performance 20% ? 10% 35%
Area Reduction 40% ~9% <20% 40%

Per Samsung’s own numbers, the foundry claims that 5LPE is either 20% lower power than 7LPP, or 10% more performance. These are actually quite important figures to put into context, particularly when we’re comparing designs which are manufactured on TSMC’s process nodes.

In least year’s review of the Galaxy S20 series and the Exynos 990 and Snapdragon 865 SoCs, an important data-point that put things into context was Qualcomm’s Snapdragon 765 SoC which was also manufactured on Samsung’s 7LPP node, and featuring Cortex-A76 cores. In that comparison we saw that The Exynos 990 and the Snapdragon 765’s A76 cores behaves very similarly in terms of power consumption, however they fell behind TSMC-based Cortex-A76 cores by anywhere from 20% to 30%.

In that context, Samsung’s 5LPE process node improving power by 20% would mean they’d only be catching up with TSMC’s 7nm nodes.

Cortex A55 @ 1.8GHz - SPEC2006 456.hmmer Power

An interesting comparison to make – and probably one of the rare ones we’re actually able to achieve today, is the comparison between the Cortex-A55 cores inside of both the Snapdragon 865 and the new Snapdragon 888. Both SoCs feature the same IP cores, clock them at the same 1.8GHz frequency, and both feature the same amount of L2 cache, with their only real difference being their process nodes.

Using SPEC’s 456.hmmer – because it’s a workload that primarily resides in the lower cache hierarchies and thus, we avoid any impact of the possibly different memory subsystem, we can see that both SoCs’ power consumption indeed is almost identical, with performance also being identical with a score of 6.84 versus 6.81 in favour of the new Snapdragon 888.

So at least at first glance, our theory that Samsung’s 5LPE merely just catches up with the power consumption and power efficiency of TSMC’s N7/N7P nodes seems to be valid – at least at these frequencies.

Further interesting data is the voltage curves of the CPUs on the Exynos 2100. I’ve extracted the frequency voltages tables of both my devices, a regular S21 and an S21 Ultra, with the above curves being the better binned chip inside of the smaller S21.

Generationally, Samsung seems to have been able to greatly reduce voltages this generation. On the Cortex-A55 cores, the cores now only require 800mV at 2GHz whilst the Exynos 990 last year in our review unit they required over 1050mV. Similarly, although the comparison isn’t apples-to-apples, the Cortex-A78 cores at 2.5GHz only require 862mV, while the Cortex-A76 cores of the previous generation required also 1050mV.

What’s also very interesting to see is the voltage curves of the Cortex-X1 cores versus the Cortex-A78 cores: they’re both nigh identical to each other, which actually lines up with Arm’s claims that the new X1 cores have the same frequency capabilities as the A78 cores, only being larger and increasing their power consumption linearly in relation to their frequency.

Samsung’s frequency tables indicate that they had been testing the A55 up to 2.6GHz, and the X1 and A78 cores up to 3.2GHz – however voltages here are quite higher and it’s also likely SLSI wouldn’t have been able to achieve similar chip yields.

Unfortunately, I wasn’t able to extract data from my Snapdragon 888 S21 Ultra, so I can’t tell exactly where it falls in terms of voltages compared to the Exynos 2100. One thing I can confirm as being quite different between the two SoCs is that Samsung does actually give the Exynos 2100’s Cortex-X1 core its own dedicated voltage rail and PMIC regulator, while the Snapdragon 888 shares the same voltage rail across the X1 and A78 cores. In theory, that could mean that in more mixed-thread workloads, the Exynos has the opportunity to be more power efficiency than the Snapdragon 888.

Generally, the one thing I want people to take away here is that although Samsung calls this their 5nm node, it’s quite certain that it will not perform the same as TSMC’s 5nm node. Usually we don’t care about density all too much, however performance and power efficiency are critical aspects that effect the silicon and the end-products’ experiences.

The Snapdragon 888 & Exynos 2100 Memory Subsystem & Latency: Quite Different
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  • Karim Braija - Saturday, February 20, 2021 - link

    Parce que je pense que le téléphone galaxy est mieux en terme de qualité et de normalité, et il est sans défauts majeurs et je pense qu'il peut durer bien plus que 10 ans. Reply
  • Cicerone - Sunday, February 28, 2021 - link

    OneUI, Samsung Knox, Samsung Pass, Secure Folder, Smart Things, updates ... yes, updates, display, service so. I can be frustrated when in Europe I can have only Exynos soc but I am not. My usage pattern will be far away from the max power of the phone. Reply
  • Spunjji - Monday, February 8, 2021 - link

    I rarely trust any kind of blanket statement about "fans" from someone whose username is literally announcing themselves as a single-issue hater. Reply
  • lmcd - Monday, February 8, 2021 - link

    Not a Samsung fan. I was hopeful that a new CPU architecture could outperform tiny stock ARM cores and instead ARM delivered a core that wasn't tiny, but happy to pillage bad results when I saw them.

    This isn't the same deal at all. This imo is equivalent to Qualcomm's 810, which disastrously rushed an A57 implementation and burned Samsung so badly that they doubled down on their current track.
    Reply
  • Spunjji - Monday, February 8, 2021 - link

    The fact that they switched from their own IP to ARM's without falling behind Qualcomm in the generational cycle would seem to support your hypothesis.

    That said, whether they'll improve "substantially" does remain to be seen - after all, they'll be integrating AMD GPU tech into a smartphone SoC for the first time since they sold Imageon to Qualcomm.
    Reply
  • lmcd - Monday, February 8, 2021 - link

    I don't expect the GPU to necessarily match up in efficiency year one, but this CPU result, if it's not from a rushed implementation, is absolutely unacceptable. Qualcomm surely isn't changing X1/A78 that much. Reply
  • melgross - Monday, February 8, 2021 - link

    Yeah yeah. Every year someone says that. Reply
  • geoxile - Monday, February 8, 2021 - link

    Mali is just crap. The Kirin 9000 is using a lower clocked, 70% wider Mali G78 configuration (MP24 vs MP14) built on TSMC N5, which is head over heels superior to Samsung 5LPE, and efficiency @ peak performance is still only on par with the Exynos 2100 configuration. In power savings mode, where it has an efficiency advantage, it's only 28% better with 70% more cores, so it's obvious avg frequency is throttled way down. Hopefully nvidia takes Mali out to the farm soon. Reply
  • FirePirate3 - Tuesday, February 9, 2021 - link

    And why i should care if snapdragon cpu and gpu is marginally better . You won't feel the cpu difference in opening chrome or facebook and such powerful gpus in phones are utterly useless. Are you launching missiles or playing Star Citizen with your smartphones guys? You can play almost all current games with a Mali 400MP gpu. The only thing that matters in this comparation is the battery life where we should give the props to qualcomm, but this is the only thing that actually matters. Reply
  • iphonebestgamephone - Tuesday, February 9, 2021 - link

    Nah, these days there are games that support 144fps and stuff, you need something like adreno 618 and up. For some stuff like genshin, to do max graphics wiyh constant 50+ fps you basically need a sd865 minimum. Reply

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