É verdade mesmo. Chama-se Paging, & seu computador fará isso automaticamente para você. Para a maioria dos usuários casuais, nenhuma intervenção é necessária, mas se a sua máquina começar a paginar, sim, ela ficará mais lenta.
Da Wikipedia, este é apenas o parágrafo de abertura ...
In computer operating systems, paging is one of the memory-management schemes by which a computer can store and retrieve data from secondary storage for use in main memory.[1] In the paging memory-management scheme, the operating system retrieves data from secondary storage in same-size blocks called pages. The main advantage of paging over memory segmentation is that it allows the physical address space of a process to be noncontiguous. Before paging came into use, systems had to fit whole programs into storage contiguously, which caused various storage and fragmentation problems.[2]
Paging is an important part of virtual memory implementation in most contemporary general-purpose operating systems, allowing them to use secondary[a] storage for data that do not fit into physical random-access memory (RAM).
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