ESP32-WROOMでの書き込み/読み込み 速度比較

#概要
個人的な忘備録的に書いておく。

#結果

1. DRAM

• 書き込み: 0.01 us/byte
• 読み込み: 0.01 us/byte

1. PSRAM

• 書き込み: 0.12 us/byte
• 読み込み: 0.10 us/byte

1. Queue

• 書き込み: 1.75 us/byte
• 読み込み: 1.84 us/byte

検証プログラム

#include <Arduino.h>

#define LENGTH  100000

QueueHandle_t xqueue;


void setup() {
    Serial.begin(115200);
  // put your setup code here, to run once:
    xqueue = xQueueCreate(LENGTH, sizeof(uint8_t));
}

void loop() {
    // put your main code here, to run repeatedly:
    uint8_t data = 0;
    unsigned long t0, t1;
    uint8_t *array = (uint8_t*)malloc(sizeof(uint8_t) * LENGTH);
    uint8_t *parray = (uint8_t*)ps_malloc(sizeof(uint8_t) * LENGTH);

    t0 = micros();
    for (int i = 0; i < LENGTH; i++)
    {
        xQueueSend(xqueue, &data, 0);
    }
    t1 = micros();
    Serial.printf("write: ");
    Serial.println((double)(t1 - t0) / LENGTH);

    t0 = micros();
    for (int i = 0; i < LENGTH; i++)
    {
        array[i] = data;
    }
    t1 = micros();
    Serial.printf("write array: ");
    Serial.println((double)(t1 - t0) / LENGTH);

    t0 = micros();
    for (int i = 0; i < LENGTH; i++)
    {
        data = array[i];
    }
    t1 = micros();
    Serial.printf("read array: ");
    Serial.println((double)(t1 - t0) / LENGTH);

    t0 = micros();
    for (int i = 0; i < LENGTH; i++)
    {
        parray[i] = data;
    }
    t1 = micros();
    Serial.printf("write parray: ");
    Serial.println((double)(t1 - t0) / LENGTH);

    t0 = micros();
    for (int i = 0; i < LENGTH; i++)
    {
        data = parray[i];
    }
    t1 = micros();
    Serial.printf("read parray: ");
    Serial.println((double)(t1 - t0) / LENGTH);

    uint8_t recv;
    t0 = micros();
    for (int i = 0; i < LENGTH; i++)
    {
        xQueueReceive(xqueue, &recv, 0);
    }
    t1 = micros();
    Serial.printf("read: ");
    Serial.println((double)(t1 - t0) / LENGTH);

    free(array);
    free(parray);
}