Research
ESP32-S31 vs ESP32-P4X Comparison
Comparison of the ESP32-S31 (announced March 2026, early sampling) and the ESP32-P4 at chip revision v3.1+, which Espressif markets as “P4X”. They solve different problems: the S31 is a wireless-first flagship (Wi-Fi 6 + BT 5.4 + 802.15.4 + GbE MAC) with mid-range HMI; the P4X is a radio-less application processor for serious display/camera/vision work that pairs with a companion wireless chip — potentially an S31.
Side-by-side
| ESP32-S31 | ESP32-P4 v3.1+ (P4X) | |
|---|---|---|
| CPU | Dual-core 32-bit RISC-V @ 320 MHz; one core has 128-bit SIMD data path (6.86 CoreMark/MHz) | Dual-core RISC-V HP @ 400 MHz (up from 360 in v1.x), AI ext + Zb, FPU, plus 40 MHz LP core |
| Memory | 512 KB SRAM; 250 MHz 8-bit DDR PSRAM I/F, simultaneous flash+PSRAM access | 768 KB L2MEM + 8 KB zero-wait TCM; external PSRAM (v3.x remaps cached L2MEM region, fixes v1.x MSPI/PSRAM DMA bugs) |
| Wireless | Wi-Fi 6 (2.4 GHz), BT 5.4 LE (LE Audio, Direction Finding, Mesh 1.1) + BT Classic, 802.15.4 (Thread/Zigbee) | None — companion-chip design |
| Wired | 1000 Mbps Ethernet MAC | USB OTG 2.0 HS, Ethernet MAC, SDIO Host 3.0 |
| Display/camera | DVP camera (8–16 bit), parallel RGB/I8080/MOTO6800 LCD up to 24-bit | MIPI-DSI + MIPI-CSI up to 1080p, integrated ISP (v3.x adds BLC, dead-pixel correction, white balance, crop), plus parallel interfaces |
| Media/AI accel | JPEG codec, PPA, 2D-DMA, SIMD core for AI/DSP | H.264 encoder (1080p@30), JPEG, PPA, 2D-DMA (v3.x: 4 TX / 3 RX ch), GDMA burst modes |
| Security | AES-128/256, RSA, ECDSA, ECC, TRNG, RAM-based PUF, secure boot, flash/PSRAM encryption, TEE + APM | Same core set; v3.x adds P-384 ECC/ECDSA, DPA-resistant AES, HMAC/RSA_DS keys in KMU, 8 PERI-APM ranges (was 2), 32 PMP entries |
| GPIO / touch | 60 GPIOs, 14 touch channels | 55 GPIOs, touch supported; v3.x adds deep-sleep hold on all IOs |
| Availability | Samples to select customers only; no retail pricing/date | Shipping; v3.x needs ESP-IDF ≥ 5.5.3 / 6.0 |
Choosing
- Connected product, modest UI (smart appliance panel, Matter/Thread device, BLE Audio, Ethernet gateway): S31 does it in one chip. Its Wi-Fi 6 + 802.15.4 + BT Classic + GbE combo is unique in Espressif’s lineup — no prior ESP32 had Wi-Fi 6 or BT Classic on RISC-V.
- Rich HMI or camera/vision (1080p MIPI display, ISP pipeline, H.264 streaming, USB HS): P4X is in a different class. The S31 tops out at parallel-RGB LCD and DVP camera — no MIPI, no ISP, no H.264.
- Complementary, not competing: Espressif positions the P4 to pair with a wireless companion, so S31 + P4X gives Wi-Fi 6 plus a full multimedia pipeline.
P4X caveats
- “P4X” is not a separate part number — it denotes ESP32-P4 silicon at revision v3.1 or later (used on e.g. the ESP32-P4X-Function-EV-Board).
- v3.x made board-level hardware changes: pin 54 NC → VDD_HP_1, USB circuit changes (1 MΩ resistor removed), DCDC circuit additions — v1.x PCB designs need updating.
- Firmware built for v1.x won’t run on v3.x (and vice versa); mixed product lines need separate images per revision.