Why gl_pointsize is visually different on iphone 6 and 6s?

When I use the same number for gl_pointsize for an APP, the point displays much larger on 6s than 6. This makes me wonder if there is something I need to notice my app about the hardware to set differnt gl_pointsize?


Hope some experts or people have similar experiences can share some hint!


Thank you.

Why gl_pointsize is visually different on iphone 6 and 6s?
 
 
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