Thoughts on the Nintendo Switch SoC, Performance, and Power Usage

I've seen a lot of discussion on the internet that vaguely references the Nintendo Switch's performance capabilities, the "miss" about using the Tegra X1 over the Tegra X2, and its capabilities as it stacks up to the XBO and the PS4, but I don't think I've seen a thread dedicated to hard-numbers analysis of exactly what the Switch, along with its SoC, is capable of, compared to the Wii U, Xbox One, and PS4, and I wanted to do something like that.

As a brief background, I do Pre-Silicon Engineering work at one of the major Computer/Graphics Processor companies, so I'll be reaching back into history a bit for some of my comparisons.

Switch and Wii U

The first thing I want to look at is the notion that the Nintendo Switch is no more powerful than the Wii U. Both consoles offer roughly ~380GF of performance in docked, home console mode. However, the Wii U is based off of the R700/RV770 chip that was first introduced in 2008 that went into ATI 4XXX and ATI 5XXX chips. The Switch is (according to current rumors) using the Tegra X1, a chip capable of around 512GF, but about ~380GF in the Nintendo Switch. I'll do my analysis assuming the rumors are correct for now.

Maxwell is FAR more efficient than AMD/ATI's RV770 chip per GF – Maxwell was one of the most efficient architectures ever prior to its release in ~2014, and the RV770 is a GPU chip from 2008. Maxwell is already ~50% more efficient per GF than GCN1 which is found in the original GCN chips and the XBO and PS4, and it should have no problem at all eclipsing the Wii U by at least that margin in terms of raw power.

Switch and XBO/PS4

Now I want to bring up the performance compared to the XBO/PS4. The XBO is a 1.3TF chip, and the PS4 gets around ~1.8TF of performance. If Maxwell is about ~50% more efficient than Gen1 GCN which the XBO and PS4 use, that puts the X1 at hypothetically a bit over half the power of an XBO, but in a handheld form factor. Even if Nintendo had elected to go with the Tegra X2 (something that I don't think would have worked – below), they would have had a max of 750GF of FP32 performance (the metric that matters). We already know that Nintendo only used a portion of the X1's power, so the X2 probably would have been about ~500GF docked, which is still around only 60% of the XBO.

It's easy to see why Nintendo couldn't do anything much more powerful though. The original XBO uses 120W at load in a game, the PS4 uses even more on account of its more powerful GPU. The Switch exists because Maxwell is incredibly efficient. The Tegra X1 brings performance to about half of an XBO while using nearly an order of magnitude less power. Maximum power consumption for the Switch likely doesn't go over about 10-15W, maybe a little bit more because it does have an active fan. Battery life is already strained by this, putting in something more powerful would have just made things shorter.

Tegra X1 vs Tegra X2

The solution then, that a lot of people have talked about, is to have used the Tegra X2, a chip that provides 50% more raw performance than the X1 (~750GF of FP32 performance. It has 3x the FP16 performance, but that doesn't matter). As mentioned above, this still would have brought Nintendo only to about 60% of an XBO (when accounting for more efficient Maxwell), still leaving a hardware gap. But, even though the X2 is on Finfet and using Pascal, it may not be much more efficient than the X1. The GPU certainly is; we already know that a GTX 1060 can provide 980 performance at ~66% of the power, but the CPU is likely MUCH more power hungry than the X1.

The X1 CPU uses 4 ARM A57 cores as its main CPU; power hungry for sure. The X2 uses 4 ARM A57 CPUs as the LITTLE configuration, the BIG guys are the 2 Denver cores. The CPU could EASILY eat into the power budget gained by the use of Pascal, maybe even adding more power than Pascal takes away. Look at the announcements for the X1 and the X2. The X1 is clearly a mobile-first chip, the X2 is clearly an automotive-first chip. An automotive first chip doesn't strike me as something designed with power efficiency in mind; the Tegra X2 could very well have been at least as power hungry if not moreso than the X1. On top of that is the fact that the X2 doesn't seem to actually be available in huge quantities, whereas the X1 has been around forever. Shipping the Switch with an X2 could have involved some significant delays – it's REALLY risky to spend four years designing a console to use a CPU that wasn't even ANNOUNCED until August 2016.

OF COURSE, all of the rumors could be wrong, and the X2 could be in the Switch. It could also be a custom X1/X2 hybrid with A57's and Pascal tech. We won't know until somebody gets a teardown. But I think this analysis is worthwhile because the majority of evidence does point to it being an X1, and it makes for interesting analysis.

Wrap Up

The easiest solution then to rival an XBO would have been to do away with the portability aspect of the Switch and ship a home console with GTX 1050 levels of performance; that would have shut up all of the pain about Switch performance levels. But it would have thrown away what many (including many here I suspect) think is the Switch's best aspect, which IS it's portability. If you accept the fact that the Nintendo's next console needed to include portability (a good idea given that's the market they own), then I really don't think it would have been possible to make the switch much more powerful than what it is today.

I'll also add that I think there's space for both the Nintendo Switch and the Xbox One/PS4. The Switch is a completely different product sector, with overlapping but not identical markets. The people who JUST want a home console are obviously going to be disappointed. On the other hand, anybody looking to get a more mobile device is going to be treated to the best mobile handheld in the world that can also hook up on to your TV for good visuals. While that will disappoint one group, Nintendo clearly believes they have a bigger market attracting people who want a mobile feature than purely people who just want a home console. History will prove them right or wrong, but given their success with the 3DS, it's not hard to believe. And, believing that, the Switch is a pretty reasonable hardware compromise.

Thanks for reading; I hope at least a few people enjoyed a by-the-numbers analysis! If you have any questions, concerns, or general comments, please let me know!

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