Ethreum-Storing Structs is costing you gas

gas_test.ts

import { Address } from "cluster";
import { BigNumber, Contract, Signer } from "ethers";

const { expect } = require("chai");
const { ethers } = require("hardhat");

describe("Gas Test", function () {
  let account1: Signer;
  let account2: Signer;
  let gasTest: Contract;

  beforeEach(async function () {
    [account1, account2] = await ethers.getSigners();
    const GasContract = await ethers.getContractFactory("GasTest");
    gasTest = await GasContract.deploy();
    await gasTest.deployed();
  });

  it("Should success1 - gas test", async function () {
    const tx = await gasTest
      .connect(account1)
      .save1(Date.now(), 123123, 8, 0, 3);
    const receipt = await tx.wait();
    console.log(receipt.gasUsed);
  });

  it("Should success2 - gas test", async function () {
    const tx = await gasTest
      .connect(account1)
      .save2(Date.now(), 123123, 8, 0, 3);
    const receipt = await tx.wait();
    console.log(receipt.gasUsed);
  });

  it("Should success3 - gas test", async function () {
    const tx = await gasTest
      .connect(account1)
      .save3(Date.now(), 123123, 8, 0, 3);
    const receipt = await tx.wait();
    console.log(receipt.gasUsed);
  });


  it("Should success4 - gas test", async function () {
    const tx = await gasTest
      .connect(account1)
      .setCharacter(0, account1.getAddress(), Date.now(), 8, 0, 3, 123123);
    const receipt = await tx.wait();
    console.log(receipt.gasUsed);
  });
});

GasTest.sol

//SPDX-License-Identifier: Unlicense
pragma solidity ^0.8.13;
// import "./Vault.sol";
import "hardhat/console.sol";

contract GasTest {
    //Type1
    address owner;
    uint64 creationTime;
    uint256 dna;
    uint16 strength;
    uint16 race;
    uint16 class;
    mapping(uint256 => address) owners;
    mapping(uint256 => uint64) creationTimes;
    mapping(uint256 => uint256) dnas;
    mapping(uint256 => uint16) strengths;
    mapping(uint256 => uint16) races;
    mapping(uint256 => uint16) classes;

    function save1(
        uint64 _creationTime,
        uint256 _dna,
        uint16 _strength,
        uint16 _race,
        uint16 _class
    ) external {
        owners[dna] = msg.sender;
        creationTimes[dna] = _creationTime;
        dnas[dna] = _dna;
        strengths[dna] = _strength;
        races[dna] = _race;
        classes[dna] = _class;
    }

    //Type 2
    struct GameCharacter2 {
        address owner;
        uint64 creationTime;
        uint256 dna;
        uint16 strength;
        uint16 race;
        uint16 class;
    }
    mapping(uint256 => GameCharacter2) characters2;

    function save2(
        uint64 _creationTime,
        uint256 _dna,
        uint16 _strength,
        uint16 _race,
        uint16 _class
    ) external {
        characters2[_dna] = GameCharacter2({
            owner: msg.sender,
            creationTime: _creationTime,
            dna: _dna,
            strength: _strength,
            race: _race,
            class: _class
        });
    }

    //Type3
    struct GameCharacter3 {
        address owner;
        uint48 creationTime;
        uint16 strength;
        uint16 race;
        uint16 class;
        uint256 dna;
    }
    mapping(uint256 => GameCharacter3) characters3;

    function save3(
        uint48 _creationTime,
        uint256 _dna,
        uint16 _strength,
        uint16 _race,
        uint16 _class
    ) external {
        characters3[_dna] = GameCharacter3({
            owner: msg.sender,
            creationTime: _creationTime,
            dna: _dna,
            strength: _strength,
            race: _race,
            class: _class
        });
    }

    //Type4
    struct GameCharacter4 {
        address owner;
        uint256 creationTime;
        uint256 strength;
        uint256 race;
        uint256 class;
        uint256 dna;
    }

    mapping(uint256 => uint256) characters4;
    mapping(uint256 => uint256) dnaRecords4;

    function setCharacter(
        uint256 _id,
        address owner,
        uint256 creationTime,
        uint256 strength,
        uint256 race,
        uint256 class,
        uint256 dna
    ) external {
        uint256 character = uint256(uint160(owner));
        character |= creationTime << 160;
        character |= strength << 208;
        character |= race << 224;
        character |= class << 240;
        characters4[_id] = character;
        dnaRecords4[_id] = dna;
    }

    function getCharacter(uint256 _id)
        external
        view
        returns (
            address owner,
            uint256 creationTime,
            uint256 strength,
            uint256 race,
            uint256 class,
            uint256 dna
        )
    {
        uint256 character = characters4[_id];
        dna = dnaRecords4[_id];
        owner = address(uint160(character)); 
        creationTime = uint256(uint40(character >> 160));
        strength = uint256(uint16(character >> 208));
        race = uint256(uint16(character >> 224));
        class = uint256(uint16(character >> 240));
    }
}