Stockfish NNUE engine - how to remove?

In your awesome puzzle mode, I frequently find myself making a subtle mistake and turning on the engine to see why.

The problem is that I have an older smartphone with limited memory and a slower CPU.

The new NNUE engine (Stockfish 13, I think) is much slower to load (and analyse). And when it is switched off, it makes Chrome lag a lot, often lock up or crash.

NNUE might be stronger on top end hardware, but the experience on lower end hardware is poor (and because the engine analysis speed is much lower than the non-NNUE version, actually weaker on slower CPUs with limited time).

The older Stockfish 12 engine was perfect. It is incredibly strong, super fast and I never had any lag/lockup/crashes.

Could we have a user preference option please to choose which engine to use for game analysis?

#1 "Note that NNUE is most likely crunching fewer nodes per second than Stockfish with classical evaluation, but it is stronger nonetheless."
lichess.org/blog/YDOKRxQAACgAREB3/stockfish-13-nnue-on-lichess

@Toadofsky: Possibly, though because of the horizon effect, the older brute-force approach will work better with limited processing resource (time, CPU, memory, etc) in many positions. Both Stock 12/13 are > 1500 Elo strong than me, so a few Elo here or there is not the issue! :)

This is about the memory footprint and CPU requirements of the engine, which are substantially lower with 12...and it didn't crash my device.

Fine for the default to be 13 NNUE, but really need an option somewhere of to use an older (and faster, quicker-to-load, etc) engine.

@Toadofsky
It's not just slow - it's a bug. On some devices it'll say "loading engine" forever, regardless of internet quality/speed, and local storage. Whatever "does this device support NNUE" detection there is is broken.

#3 #4 Thanks, I just wanted to confirm that the issue had to do with starting the engine, as opposed to being about how fast it computes.

I'm not sure what solutions are available; any change will add at least some complexity. Best would be if somehow github.com/official-stockfish/Stockfish could be persuaded to solve this issue, although I don't think they are interested.

@Toadofsky: The primary issue is the speed of loading, and the resources it requires to run (as I understand it to load the pre-learnt ML model it uses to evaluate the positions). On my (older) phone, Chrome becomes laggy, and can crash. Even when I minimise Chrome, the whole phone is nearly unusable. I have to actually kill the Chrome process to sort it out.

The older Stockfish 12 never had this issue (and loaded lightening fast).

Can't this just be an option? if (m_stockFish == 12) DoThis(); else if (m_stiockFish ==13) Do that();?

#6 I can't promise anything; for years Fabian Fichter & I contributed Multi-Variant Stockfish to Lichess, who generously deployed and helped troubleshoot it. They also accepted many other UI/UX suggestions I offered.

Now I feel guilty as I do not have time to maintain my Lichess contributions (ideas and code). At the same time, Lichess is supporting multiple apps, many browsers, many versions of those browsers, etc.; this is only feasible by not also introducing needless "options" when really the browser developers need to fix their bugs.

You can simply disable NNUE in the analysis settings (the menu in the bottom right corner of the moves list). The non-NNUE Stockfish won't get any more improvements going forward though but it should still be good enough for most cases.

#7 Your contributions, and other open-source developers, is incredible...but don't blame either the user or the browser! It worked with SF 12 and doesn't with SF 13. Nothing else has changed. A setting to choose which engine to use is hardly "needless". There are going to be many variables that you cannot control (like browser bugs or resource-constrained) which could be resolved by choosing an engine that works for the user.

#8 @benwerner: That worked for me, thanks! For those having similar problems, follow these steps:
1) Go to your profile and load one of your recent games
2) Select the analysis board
3) Select the hamburger symbol (3 horizontal stripes) and scroll down to the analysis options
4) Find and disable "Use NNUE"
5) Close and kill your browser
6) Reopen the browser and lichess and you should find "Use NNUE" is off and you are using an older version of Stockfish (on mine, Stockfish 11 NCE)

Thanks for that update! The engine now loads and works faster and I can start and stop analysis without the browser locking up and crashing.