Tree performance

Hi,
I have to store some larger number of arrays in TTree. My question is : is there a diference between tree with many “small objects” (like NTuples) and between tree with smaller number of entries but stored as a object.
I will read entire tree, and array has >100 floats (therefore I suppose that penalty for additional TObject members will be relatively small)

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I think @pcanal can help you.

for additional TObject members will be relatively small

Object stored in a TTree do not need to inherit from TObject; so don’t unless you are actually using TObject’s features.

with many “small objects” (like NTuples) and between tree with smaller number of entries but stored as a object.

I am not sure I understand the transformation you have in mind, in particular how it related to the number of “entries” (which type of entries are you referring to?)

Lets say that the question is "what is faster? - tree with 1M of integers or tree with 1k of entries with arrays (with size of 1k integers)

Not even counting the problem/cost with re-assembly of the arrays, the case " tree with 1M of integers" will be slower (and lead to a larger file) than the case "1k of entries with arrays (with size of 1k integers)"

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