ESP32-S31

[eriksl]

Just very sparsely technical specifications available, mostly marketing speak...

What do we actually know?

It looks like a ESP32-S3 but
- the two Xtensa cores are replaced by RISC-V cores (which was to be expected)
- classic Bluetooth (re-)added
- gigabit PHY added
- MCPWM removed?
- Thread/Zigbee added?
- more GPIO pins (60!?)
- JPEG hardware codec
- a lot of added "security" features (aka: IP protection) that are not interesting at all for us hobbyists

Good that there's full SPI-RAM support now, on a RISC-V based SoC.

The core's speeds are the same as the Xtensa's cores in the S3. I am a bit worried that the processing speed of "normal" code will therefore be less on this SoC.

It's a pity (IMHO) it doesn't support the 5 GHz band. For serious applications, one should really use 5 GHz.

Also the amount of internal RAM remains the same. That's really an issue, because a lot of internal RAM is assigned to all sorts of "internal" things, so there really isn't that much left for an IDF application. In my case I already moved everything possible to SPI-RAM, including LWIP, Bluetooth and the stack of most threads and still I only have ~50 kB left for DMA etc. I also lowered the threshold for the allocator to assign to internal RAM to block to internal RAM to only 32 bytes...

I am very interested whether the known limitations the S3 have been addressed. Like the very limited bit-width of the LED PWM modules. Some limitations of the I2C modules and whether the ULP I2C will be really usable now.

[Sprite]

The core's speeds are the same as the Xtensa's cores in the S3. I am a bit worried that the processing speed of "normal" code will therefore be less on this SoC.

-S3 is 240MHz, this chip goes to 320MHz, so it's a fair bit of increase. Aside from that, the cores in the -S31 will be derived from those in the -P4 (which are a lot more fancy than the aging LX7 cores in the -S3 so they have more MIPS/MHz). Without making any guarantees here (as I haven't seen any tests for the -S31 myself) I imagine you can use this as an indication of what a speed comparison could look like.

It's a pity (IMHO) it doesn't support the 5 GHz band. For serious applications, one should really use 5 GHz.

We have 5G IP now and you wouldn't be the only one asking for a chip that is more powerful than the C5 that is equipped with it. I'm not gonna comment on our roadmap in any way, but you can surely imagine the C5 is not the last chip with 5G support we make.

[eriksl]

Hi,

Thanks for your comments!

So for the moment I am seeing the S31 as an "intermediate" model to the real serious showstopper then.

I am really surprised of the amount of models Espressif has introduced over the last two years. Some of them are almost exactly the same of another model, but apparently there is a valid business case for it.

I'll try to be patient again

EDIT: ah now I get it. S31 = S3.1. So I'll be waiting for the S4 A bit confusing though, RISC-V cores in the S series.

[mikemoy]

I am really surprised of the amount of models Espressif has introduced over the last two years. Some of them are almost exactly the same of another model, but apparently there is a valid business case for it.

Ya, I dont know about all that. Why make 20 products along with all the R&D, support & documentation you need that goes along with it. When you can just dump all you got into one or two. You will make more of them, and odds are they will be even lower cost since your making more.

[eriksl]

I always though the same, but apparently it's otherwise.

[Sprite]

Ya, I dont know about all that. Why make 20 products along with all the R&D, support & documentation you need that goes along with it. When you can just dump all you got into one or two. You will make more of them, and odds are they will be even lower cost since your making more.

I'm not on the business side, so part of this is speculation, but we sell a lot of chips here, some of which go into devices that are produced in very large numbers. For those devices, I can imagine manufacturers to be really cost-sensitive, and it helps to have a chip for them that matches their requirements as close as possible - if the chip has less than they need, they cannot use it; if it has more than they need, it's too expensive and some competitor might have a chip that is cheaper and still does what they need.

[eriksl]

Yeah sounds plausible, and other manufacturers do this as well. I just find it a bit silly that Espressif creates an embellished announcement with all superlatives and marketing hype terms each time. Intel and AMD also make CPU's on demand, I don't think they do the "announcements" like this.

Just a bit frustration here, sorry for that, because each time I get all enthusiastic about a new type being announced and it turns out to be "not particularly that spectacular"

[Sprite]

Just a bit frustration here, sorry for that, because each time I get all enthusiastic about a new type being announced and it turns out to be "not particularly that spectacular"

We're a public company registered in Shanghai, and the Chinese stock market is, more than the western one, a market of retail investors, so I imagine our IR team has a hand in this hyping up whatever makes the company seem more attractive. All part of the game.