PS cutting height 1px, Y-axis tiling background image problem

scene ：

Use the above figure as the background , Fill in the text . A cutable graph is divided into three parts ：

It should be noted that
The height of the second picture should be controlled as 1px. You might say why not cut a big piece , Isn't it better to tile with fewer blocks ？ It's not . The smaller the load, the faster .

The main advantages of this are ：
1、 This saves space , Especially in front-end web design , Using a whole picture as a background is better than 1px The big n times .
2、 Save loading time .