Felixews.com – The developers behind the open-source PlayStation 3 (PS3) emulator RPCS3 have announced significant progress in emulating the PS3’s Cell Broadband Engine processor. This breakthrough was discovered by lead developer Elad, who successfully identified previously unrecognized SPU usage patterns and created new code paths to generate more efficient native PC output.
This improvement benefits every game in the emulator’s library. Titles that are highly SPU-intensive, such as Twisted Metal, show an average FPS increase of 5% to 7% between build versions v0.0.40-19096 and v0.0.40-19151.
The PS3’s Cell processor combines a PowerPC-based PPU with up to seven Synergistic Processing Units (SPUs). Each SPU is a 128-bit SIMD coprocessor with its own 256KB of local memory. RPCS3 emulates SPU workloads by recompiling native Cell instructions into native x86 code using the LLVM and ASMJIT backends. The quality of this translation determines how much host CPU time is consumed per emulated SPU cycle.
SPU emulation is the biggest CPU bottleneck in RPCS3. Although the PS3 can run up to six SPUs simultaneously for game workloads, each SPU must be recompiled and executed on a host CPU thread. Elad’s contribution identified new patterns in how PS3 games use SPU instructions and implemented more efficient recompilation for them. This optimization reduces overall CPU overhead.
RPCS3 also shared a side-by-side video comparison of Twisted Metal showing an increase in frame rate. This improvement is said to benefit all CPUs, from entry-level to high-end, and cites user reports of better audio rendering and slightly better performance in Gran Turismo 5 on an AMD Athlon 3000G dual-core.
Elad, known within the RPCS3 codebase as elad335, has a long track record of SPU optimization work on this project. His SPU optimizations in June 2024 have yielded performance gains of 30% to 100% on quad-core, quad-thread CPU configurations, with titles like Demon’s Souls seeing a doubling of frame rates on hardware-constrained systems.
In March, RPCS3 achieved over 1,500 FPS on the title screen of Minecraft PS3 Edition, a benchmark the project uses to demonstrate the efficiency of its recompilation pipeline. A few weeks later, in the latest SPU update, the project also added new Arm64 SDOT and UDOT instruction optimizations to speed up SPU emulation on Arm hardware, including Apple Silicon Macs and Snapdragon X laptops.
User Interface Update for Handheld Devices
In addition to performance improvements, the RPCS3 emulator also received a new user interface (UI) designed for handheld PCs like the Steam Deck. This update significantly polishes the in-game overlay, providing a more controller-friendly experience. The new interface resembles SteamOS, allowing quick access to important options.
Previously, users had to navigate through layers of menus to access graphics or audio settings, and not all settings could be adjusted while the game was running. Now, by pressing Start + Select, the overlay provides direct access to options such as taking screenshots, saving game states, restarting the game, and a settings menu where most options can be adjusted without needing to dig deeper.
Key graphics options such as resolution scaling and frame rate limits are now easily accessible and adjustable. More advanced settings are also available, though they may be less intuitive for new users due to the absence of tooltips like those found in the desktop UI. However, there is also a performance overlay that can be easily toggled on or off to monitor frame rates, and most settings can be changed without having to restart the game—even the rendering resolution.
This update makes performance tuning on devices like the Steam Deck or ROG Ally relatively easy. RPCS3 has enabled all games from the PlayStation 3 library to run, even restoring online matchmaking features for some favorite titles.
The RPCS3 emulator currently lists over 70% of the PS3 game library as playable and supports Windows, Linux, macOS, and FreeBSD, with native Arm64 architecture support set to be added by the end of 2024.