A Note on Storage Fragmentation and Program Segmentation The main purpose of this paper is the presentation of some of the results of a series of simulation experiments investigating the phenomenon of storage fragmentation. Two different types of storage fragmentation are distinguished: (1) external fragmentation, namely the loss in storage utilization caused by the inability to make use of all available storage after it has been fragmented into a large number of separate blocks; and (2) internal fragmentation, the loss of utilization caused by rounding up a request for storage, rather than allocating only the exact number of words required. The most striking result is the apparently general rule that rounding up requests for storage, to reduce the number of different sizes of blocks coexisting in storage, causes more loss of storage by increased internal fragmentation than is saved by decreased external fragmentation. Described also are a method of segment allocation and an accompanying technique for segment addressing which take advantage of the above result. Evidence is presented of possible advantages of the method over conventional paging techniques. CACM July, 1969 Randell, B. storage allocation, storage fragmentation, paging, segmentation, addressing 6.2 6.20 CA690701 JB February 17, 1978 9:46 AM 1879 4 1879 1884 4 1879 1901 4 1879 2095 4 1879 2277 4 1879 2297 4 1879 2365 4 1879 1754 5 1879 1879 5 1879 1879 5 1879 1879 5 1879 2095 5 1879 2218 5 1879 2498 5 1879 2596 5 1879 2734 5 1879 2902 5 1879 2911 5 1879 3000 5 1879 1051 6 1879 1062 6 1879 1184 6 1879 1184 6 1879 1211 6 1879 1380 6 1879 1552 6 1879 1572 6 1879 1728 6 1879 1728 6 1879 1751 6 1879 1751 6 1879 1754 6 1879 1752 6 1879 1810 6 1879 1879 6 1879 1879 6 1879 1879 6 1879 1879 6 1879 1879 6 1879 1879 6 1879 1879 6 1879 1879 6 1879 273 6 1879 2095 6 1879 2095 6 1879 2095 6 1879 2435 6 1879 2435 6 1879 2435 6 1879 2498 6 1879 2596 6 1879 2734 6 1879 2734 6 1879 2747 6 1879 2768 6 1879 2773 6 1879 2864 6 1879 2983 6 1879