Kopy,

UDT is not designed for long lists, as it renders everything in memory. Consider to split the UDT in two lists, however that depends on your use case.I can't give you a general advice beside from adding memory to your server, though it also depends on the data types. For example links or date times are usually slower that string cells, as UDT needs to calculate some helper columns. Enabling paging would reduce the data that is returned to the client.