STATUS

A complete new development-system for the stm32mp257 is now up and running.

Cross-compiling was already successfully, the codesize is comparable to the stm32mp157.

A newer version of the OS has been flashed now to another SD-card using the Cube-Programmer and USB.

The latest version 25.06.11 is now working and actually in use on the board.

Here, a match between the 2 boards is in full swing:

There is an speedup of ~70 % compared to stm32mp157.

The STM32MP257 has 4 GB  RAM onboard.

So hashtables may be in use up to around 3.5 GB.

In practise the RAM available on the STM32MP157 ( 1 GB ) is already more than sufficient.

The engines are running quite fast, depth 20 will be usually reached within a few seconds.

According to status-monitor there are only around 5% in use from other processes like Python or weston using the default-OS from SD-card.

So, there would be a little speedup possible, if using a raw OS, but this can be neglected here.

I have tried different compiler-settings, but it looks like it is perfect already.

The A35-MPU is highly energy-efficient, this comes of course with some compromise regarding performance.

For an chess-engine more cores are of advantage, so having more CPU-cores would be a plus.

The main-MPU on STMx57-boards has already 2 cores, both are in use by the chess-engine.

Of course it is well known that some processors have already up to 24 cores ( or even more ).

But for an evaluation-board this should be out of question.

However, it will be interesting what comes next from STM here...

The future of chess-engines will be AI-based, this is clearly demonstrated using NNUE-based versions of Stockfish.

Stockfish 17.1 is the latest release so far, the source-code has been compiled for the STM32MP157 ( including minor modifications required for playing games ).

Compared with Stockfish 16 the size of the .nnue-files has increased a lot.

There will be allocated now > 100 MB of RAM here for nnue-data only.

A first match has been played already between Stockfish 17 and Stockfish 16 on STM32MP157:

Move-input is done using a wireless keyboard, a mouse is used to control the cursor.

It is not very comfortable but working.

After the first match the number of nodes/s using Stockfish 17 is now around 1/2 compared with Stockfish 16.

Obviously, there will be much more "knowledge" processed, interestingly nearly the same depth will be reached nevertheless.

The matches played so far can be found in the GAMES-section.

 Amazing is the CCRL-rating at the time of writing: 3640 ELO.

Stay tuned...