Disc-based MGS4 spins constantly. PKG runs entirely from HDD, quieter and cooler.

: While MGS4's frame rate is notoriously inconsistent (often dipping between 20 and 30 FPS), running from the HDD—especially if you've upgraded to a modern SSD —can help reduce texture popping and minor hitches. 3. Preservation and Hardware Health Metal Gear Solid 4 Is Better Than You Remember

Here's a rough breakdown of the PS3 and PS2 PKG file sizes: