You're referring to the infamous MGS4 IRD file patching issue!
The patch released for MGS4 addresses the IRD file issue by: mgs4 ird file patched
: Specifically designed to fix crashes (like the "cellSpurs" freeze) and improve performance. Open the RPCS3 Wiki and find the Canary code block. You're referring to the infamous MGS4 IRD file
In short: ignore the hype around MGS4 patched IRDs unless you have a very specific technical need. Stick to verified retail dumps and let RPCS3 or webMAN handle the rest. mgs4 ird file patched