The PlayStation 3 had 256 MB of XDR DRAM as its primary system memory.
Sony paired this fast XDR main memory with 256 MB of GDDR3 video memory dedicated to the console’s graphics processor. The split-memory design differed from many contemporary systems, which commonly used a more unified memory arrangement.
The PlayStation 3’s unusual architecture reflected Sony’s emphasis on the Cell Broadband Engine and its specialized processing model. Developers had to manage the console’s separate memory pools carefully, especially when moving data between the CPU, graphics hardware, and storage.
The 256 MB figure refers to the main system memory, not the total memory available across the whole machine. Adding the graphics memory produces 512 MB overall, but that is not the same as the primary-memory specification. Storage capacities also varied widely between launch and later PlayStation 3 models, so hard-drive size should not be confused with RAM.