Whether Houdini is version 15 or the latest version 18, why does it do it regardless of pyro cache or flip cache. Why cache to disk, background cache, computer memory will constantly overlap, and then directly burst memory. Isn't the background cache to disk just counting the data for the current frame? I found all the data in the previous frame, which is difficult to release. The background cache memory under win system is basically not released. Under the liunx system, the memory is also superimposed, but it will be released a little. The 64G memory tested is very large, but Houdini's background cache solves the 64G memory and counts 15 million particles. If it is less than 120 frames, the memory will burst. But naiad tested the same machine with 64G of memory. With 60G memory, a shortage of 700 million particles can be counted, and a frame buffer of 7G can count more than 240 frames. Naiad only used 60G of memory. This question is very confusing for me. Never add unlimited memory. I will add comparative data and screenshots later.