Mongoose model.save is slower if schema has sub-document or sob-document array

[Nilesh Maheshwari]

I need some clarification on why model.save is slower if schema has sub-document or sob-document array.
I am using Mongoose v4.9.4

var Person = new mongoose.Schema({
    Name: {
            type: String
    },
    Addresses: [{
        streetaddress1: {
            type: String
        },
        streetaddress1: {
            type: String
        },
        city: {
            type: Number
        }
    }]
});

Person.save takes more time if Addresses has 10000 entries.

Whereas below model.save with nested schema takes 1/100th of time with below nested schema.

var AddressSchema = new mongoose.Schema({
        streetaddress1: {
            type: String
        },
        streetaddress1: {
            type: String
        },
        city: {
            type: Number
        }
    });

var Person = new mongoose.Schema({
Name: {
            type: String
    },
    Addresses: [AddressSchema]
});

Really appreciate you help on this one.

[Wan Bachtiar]

Note: This question has been answered on https://github.com/Automattic/mongoose/issues/5925