by Bloodborne - the game that requires no introduction - a beloved classic of the PlayStation 4 generation, untouched since its original run. You can play it on PS5 but there are few immediate benefits for doing so. No frame-rate improves, no resolution bumps. Meanwhile, there's the sense that PS4 back compat on PS5 more generally isn't quite good enough - so many games on the platform still look and play great, but the sequel console could do so much more. And today, we're proving out the theory.
We've seen PS4 games enhanced for PS5 before, but somehow, the results have never quite felt as good as we'd hoped. Right now, it's our belief that these games run at lower CPU and GPU clock speeds on PS5, compared to native titles. We're also convinced that the original memory limitations of PS4 are in place too - so around 5GB for games, a little more for those with PS4 Pro enhancements.
The modder Christina put in the work here and using an exploited PS5 console, has developed a range of patches designed to unlock more potential for PS4 games running on PS5. Full system CPU/GPU clocks, an extra 4GB of system memory, and even support for 120Hz and VRR. All of these features have been brought to bear on Bloodborne, opening the door to transformed experiences.
So, what Bloodborne options are available with all of these tweaks in place? We started by using the extra memory available to increase the game's native rendering resolution to full 4K, with the oppressive chromatic aberration effect removed and with tweaks to the game's lightgrid global illumination system. This allows for the same 30fps gameplay as the original - but with a twist. Christina originally developed a patch for exploited PS4s that replaced From Software's inconsistently frame-paced 30fps cap with the Sony library alternative. So, not only do we get 4K, we also get properly paced 33.3ms frames. The game holds up across the board, even down to the game's fonts rendering at native 4K. It's only the bitmap art that remains at the original full HD.
But 60fps is the dream, right? Well, we've originally shown that many, many years ago and even showed footage of it running on PS5, but we can now take it one step further with resolution upgrades. Running at 2304x1296, the game is effectively locked at 60 frames per second, but perhaps 2560x1440 would be a better fit: the majority of the game runs at the target frame-rate, though alpha transparency effects (most often seen in boss battles) take the performance level more into the 50-60fps range. But that's where 120Hz and VRR come in.
We've seen 120Hz on PS4 apps running on PS5 before - specifically Call of Duty Warzone before the native current-gen upgrade arrived. But via modding, it seems to be the case that just about any PS4 app can run in 120Hz mode and VRR can be enabled too. Add a frame-rate unlock patch and games like Bloodborne can run at up to 120fps. Keep resolution at 1080p and you're looking at a circa 85fps-120fps VRR experience. Move up to 1440p and it's more like 50-75fps. Still, with v-sync out of the picture, input lag reduces, making for a more responsive game. It's a world apart from the original 30fps experience.
We understand that these mods will be released shortly for those with exploitable PlayStation 5 consoles - but that is a very small subset of the audience. Essentially, you need a console that hasn't had a system software upgrade since 2022. So the question is: how viable is this with official support?
There are good reasons for doing this. There are clear technical hurdles in getting enhanced PS4 games running on PS5. The game needs to run on much later SDK development environments, which all but rules out most of the older library. Sony would need to implement a system-level solution that adds extra memory for PS4 games to access to run at much higher pixel counts. And it would need to grant PS4 apps full CPU and GPU clock speeds, while also adding a per-title patching system to allow games to defeat their in-built resolution and frame-rate limits. But it is possible and if there's no chance of a Bloodborne remaster or an upgrade along the lines of prior PS4 patches, this is the only route forward.
It's not just Bloodborne that would benefit - there are many, many games where this approach would work. Batman Arkham Knight anyone? We've got the patches and they work with all the same features as the Bloodborne upgrades demonstrated here.
We're still looking into PS4 back compat for PS5 and we have a bunch of unanswered questions. Do the lower CPU/GPU clock speeds on PS4 apps translate across to the enhanced PS4/PS4 Pro games that have been officially released? Does PS4 Pro support offer more compute resources in addition to a bit more RAM? We noted that the recent Assassin's Creed Unity patch for PS5 actually adds PS4 Pro support - it just doesn't do anything on 4Pro hardware. We went into this one wondering why Xbox Series X handles back compat better than PS5 when both systems are so evenly matched - and we're still looking for answers.
To conclude, while Bloodborne is the showcase game, many others could still be enhanced - and they still hold up today. Older games still have a large role to play in the current generation and if the flow of official upgrades is slowing down, with limited features, perhaps it's time for a revamp What we're showing here is a proof of concept for improving those legacy games with minimal developer improvement but maximum impact. This isn't just back compat,or back compat plus (as we've called it in the past) but enhanced back compat featuring the PS5's full range of display features. In a sense, we've matched the Xbox Series feature set - and it's terrific to see it play out on iconic PlayStation 4 titles.