How to improve Ethernet transmission speed？

I use the functions defined below to send data.

sendData(data, 0x189C000 "192.168.137.1", 12345);

#ifndef ETHERNET_SENDER_H
#define ETHERNET_SENDER_H

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <fcntl.h>
#include <unistd.h>

void sendData(const uint8_t* data, int size, const char* destIP, int destPort) {
    struct sockaddr_in serverAddr;
    int sockfd;

    
    sockfd = socket(AF_INET, SOCK_DGRAM, 0);
    if (sockfd < 0) {
        perror("socket");
        return;
    }

    
    int flags = fcntl(sockfd, F_GETFL, 0);
    if (flags < 0) {
        perror("fcntl");
        close(sockfd);
        return;
    }
    if (fcntl(sockfd, F_SETFL, flags | O_NONBLOCK) < 0) {
        perror("fcntl");
        close(sockfd);
        return;
    }

    // set   server  address
    memset(&serverAddr, 0, sizeof(serverAddr));
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(destPort);
    serverAddr.sin_addr.s_addr = inet_addr(destIP);

     // Send the data in groups
    int blockSize = 1450; 
    int numBlocks = (size + blockSize - 1) / blockSize;
    int totalSent = 0;

for (int i = 0; i < numBlocks; i++) {
        int offset = i * blockSize;
        int blockBytes = (i == numBlocks - 1) ? (size - offset) : blockSize;

        ssize_t sentBytes = sendto(sockfd, data+offset, blockBytes, 0, (struct sockaddr*)&serverAddr, sizeof(serverAddr));

        totalSent += sentBytes;

}


    
    close(sockfd);
}


#endif // ETHERNET_SENDER_H