Modelling prior in a gaussian process using Gpytorch

I am new to Pytorch and I am using a data of size 1600 to create a Gaussian process model. Since data is big I could not create the model and I get out of memory error. I found that the prior can be modeled rather than feeding the data directly so that I can use it to create a Gaussian process model. Is there a way to do this in Pytorch. Does pytorch have any prior predict/model check methods ?