Kernel memory
It might be called "reserved virtual memory space" or "virtual memory file", depending on the operating system.
The space reserved for virtual memory varies on different computers. It depends on the operating system in use and how much system memory is available.
less
dir is reserved word (short for directory) in Microsoft operating systems. a dmp file extension is short for a memory dump. So a dir00dmp may be a dump file of a directory created by the operating system when it crashed.
Wateva
32 bit operating systems can only address 4GB of memory 64 bit operating systems can address 4 petabytes of memory(1 048 576 gigabytes).
The slab allocator in operating systems manages memory allocation by dividing memory into fixed-size blocks called slabs. Each slab is dedicated to a specific type of data structure, such as a certain size of objects. When a request for memory allocation is made, the slab allocator assigns memory from the appropriate slab, reducing fragmentation and improving efficiency. This method helps to speed up memory allocation and deallocation processes in the operating system.
poor performance
The memory requirements of the operating systems themselves is almost always lower, so you can, for instance, run modern server software on systems that could not run a modern desktop easily (or at all). However, depending on the systems purpose and its load / traffic, the system may actually require far more memory than any desktop system.
Operating systems are not installed on motherboards. Operating systems are installed on storage media or in some kind of memory including read only memory, which can be part of motherboard. The standard operating systems that work on most Personal Computer motherboards, that include an Intel compatible CPU, includes versions of Microsoft Windows, Linux, Oracle Solaris and other version of unix,
cache memory
Generally speaking, servers usually have more memory than desktops and workstations.