Mali's texture is poor than buffer, why?

I tested the performance of mali's texture(cl_image), I found it is poor than buffer(cl_mem).

my GPU is mali G76

I think the texture should be better than buffer, such as: bilinear.

but, my test tell me G76's texture is poor than buffer about 10%-20%. my test format is RGBA

I don't know why?

is there anyone would like to tell me the secret?

or, is there any standard benchmark program?