Forums  /  Resident Evil series  /  Resident Evil  /  Biohazard PC Patch (JP ONLY)

If you can read at what framerate the menus run in PS1 maybe we can know. But I'm guessing 60fps menus and doors are doing something with the IGT of this version. Full 30fps lock with Bandicam seemed to be "okay" regarding the IGT/RTA time match.

Other than these IGT issues, the patch is great to finally run the game in hardware mode and windowed mode without issues and with the correct graphics.


If you can somehow make a .exe that shows the IGT (however basic, could literally just be the timer, nothing fancy like Dchaps' SRT's or anything) then we maybe can finally get to the bottom of this.

I think several people running this with an IGT on screen could help us maybe determine exactly what the problem is and where it lies.

Mainly because we can then time cutscenes/rooms, etc based off of the IGT.


And I know I do sound a little biased here but if you go back and watch Zenix's 40:20 RTA test using the method I posted, even though I do still believe that not to be a foolproof method, his IGT time was pretty much accurate to RTA.

Taking into account that he started his time after clicking Jill's name plate and ended it after the screen faded to black and the ending FMVs began his RTA was 40:20 and his IGT was also 40:20.

This is pretty much gonna be a case of whatever works best for you, in my opinion. It would also help to 100% know when this version's IGT starts and ends.


IGT is based on the number of game ticks processed. Divide the ticks by 30 to get the final time in seconds.
A "tick" in this situation is determined only by the game's speed, not FPS locks.

Biohazard has a frame rate issue obviously. The limiter is unstable when the computer is able to process more than 30 frames a second. Strangely the game is running faster while sound clips are playing, but since the voice clips are the same speed regardless, a lot of time is added to the final IGT. My patch seems to fix this just fine, and any "de-sync" issue with cutscenes is just a PC-related issue.

This is a bug in the PC version. The menu is running at 60 ticks per second, so double the time spent in menus will count towards the IGT. Limiting to 30 FPS does not match RTA, since the game still attempts to run 60 ticks per second during menus. It is an oversight on the developers' part. What should we do? I would not fancy fixing this. My purpose was to fix the frame rate issue and make it as speed-runnable as possible, not fix all bugs/glitches with the game.

IGT starts as soon as the first cut scene begins (after skipping "They have escaped into the mansion")
IGT ends as soon as the final FMV begins (after sending a signal and after the screen completely fades out)

The game excludes these from the IGT:
- Room transitions
- Menu fade in/out
- FMVs
- Game is in background
- Options menu
- "Exit to Title" screen
- Save screen (typewriter)

The IGT is running twice as fast in the menu, regardless of 30 FPS or 60 FPS. The game tries to run the menu at 60 ticks per second.

Basically only the in-game, cutscenes, and inventory screens count.

IGT is inaccurate regardless of running the menu at 30 ticks per second.

Maybe I'll push out a timer tool so you can see for yourself.


Judging from these videos, the PC version is still running way faster. I'm thinking of buying a computer with specs equivalent to the recommended system settings for this game. If I do, I'll do a run and get a benchmark for how it's supposed to run. I probably won't be able to get a frame counter for it, but if we keep setting framerate caps we'll be able to get an idea of the max framerate it's supposed to have.

what about 25FPS? 25FPS is PAL framerate, but chances are the engine is adjusted to work differently for the PC version.



The game ticks are not synced to FPS.
Game ticks are 30 per second and 60 per second for in-game and menu/doors respectively.

Frame cap doesn't matter unless it can process more FPS, in which case more ticks are processed per second. It's strange. Setting to 25 or 15 FPS the game will still run 30 ticks per second (or at least attempt to). If 40 FPS is possible, it will run 40 ticks per second, but if the FPS cap is 30, there is no speed up.

The IGT is calculated from the amount of game ticks processed (GameTicks / 30). It does not account for additional menu ticks, so the IGT is running twice as fast during menus.

Pretty sure it's 30 and 60.

I believe my patch is letting the game run at intended rates, so I think we should go with RTA for PC.


I am against RTA on RE1 PC for a few reasons:

1. We've already seen the game will very visibly run at varying speeds (even with the patch as Carcinogen mentioned above) and have visible speed up quite often. This, alone, pretty much effectively makes RTA useless.

2. People running the game on old hardware, and thus getting the actual performance the game is supposed to be at will suffer in terms of RTA because the chances are they will get very little speedup compared to someone running on modern specs. Their experience, I imagine, would be a lot closer to what was intended than anything any of us could get, no matter how much we mess around with this.

The main other reason, is this game isn't even intended to run off of a HDD... it's supposed to load from the disc at every door. The reason I know this is because I've played it from an actual disc, and every time I hit a door the load times would be about 2-3 secs for each door skip and the drive was actively scanning the disc everytime I hit a door.

Running this game off of a Virtual Disc using programs like MagicISO would be very unfair in this case to anyone wishing to just play the game the way it was intended, which is off of the physical disc. Which would then mean programs like MagicISO (or running it Virtually period) would also have to banned on account of people running it legitimately would then be at a ridiculous disadvantage in the case of RTA.

Most importantly; it's also worth noting that even PSXjin has mild speed-up, and that isn't even visible to the naked eye most of the time. But it's well known that PSXjin will land usually between 3-10 seconds difference in RTA/IGT because the emulator, whilst stable, isn't perfect.

Think how much difference this version is gonna have, when it's all over the place and very visibly so.


Okay I have an idea for the next patch. Instead of syncing FPS, I can sync game ticks instead. If I account for menu ticks I can provide an accurate IGT (or just forgo 60 FPS menus).

In 1.1 - 1.4 I have intercepted the frame presentation function and limited that to 30/60 per second.

Instead I will limit the game ticking function.

I think it will even be possible to keep 60 FPS menus while keeping the IGT accurate.


I think that would work
I would really like the pc speedrunners for this game


I'll start test running it when the next patch is out.


It's been a while since an update.

1.5 is now available, which syncs game ticks instead of FPS.
This patch fixes a lot of spikes in speed during screen transitions as well as some cut scenes.

It seems some cut scenes are too slow, but possibly due to audio clips loading too fast (they're delayed on console hardware), which would make it a PC engine-related problem. A good example is the Jill/Barry cut scene where you get Acid Rounds. Barry speaks too early...


It has been a long time since an update.
I have updated the patch to 1.6, as well as made a livesplit script so you can read the game timer.

Specifically, it fixes the timer in menu so it doesn't run double speed.

Everything but FMVs will count towards the IGT.

TaPTaP likes this. 

End game IGT is acting strange. I know when I changed the game time value before the end that the IGT would change accordingly, but it's inconsistent now when playing from New Game to the end.

EDIT: Woops, was reading the wrong frame counter, this game has several Kappa

EDIT2: Version 1.6.1 now reflects the correct timer. You can update the auto splitter too, but it should not make a difference.

The timer works like before. Doors, (some) screen fading, and FMVs will not count towards the IGT.


Test sample run for 1.6.1 patch
( in two parts because OBS crashed Kappa )
The top timer is RTA
The bottom timer is IGT

zenixzenix likes this. 

I think 1.6.1 with the Livesplit IGT is going to be good enough to run this legitimately IMO. We need more people to test in different kinds of hardware of course but just knowing that the IGT lies way behind RTA in this game (as it should be) gives me hope of stability.


I've done several test runs and the IGT seems to remain consistent.

I always have 45.10 seconds IGT at the first door in Jill,
and I know where I'm gaining and losing time in splits.


Did you finish the game and get the same time that the one show in game after credits?

edit: sorry didn't look at the video. Nice job!


Updated to 1.7. There is not likely to be a speed patch in the future due to the way the new patch works.

In previous patches, I have used my own timing code to fix the speed of the game. But now I have discovered that the wacky speed of the game was caused by a faulty instruction in the game code. The game now runs like Biohazard 2 in terms of speed. It even has the bug where the game runs at PAL speed, which can be fixed by running some media in the background (Windows Media Player, YouTube, etc.).

You can even replicate the speed patch by setting the bytes at 165E7 in Biohazard.exe to "90 90 90 90 90 90". However, it will not fix the IGT problem where the menu advances the IGT twice as fast. My patch already fixes the IGT.

So all my patch does now is remove the faulty instruction, allow windowed hardware mode, and IGT fix for menu.

TaPTaP likes this. 

I'll give this a few runs and see how it goes, but it's playing well so far. I wonder if this works with the MediaKite version I bought 😃 lol. Also, any idea on how configure the keys in-game? I use a gamepad BrokeBack

EDIT: NEVERMIND I AM STUPID. There's an option button OpieOP


Hey Supergamer57, I just wanted to say thank you so much for the patch. It finally made the game run perfectly for me. Thank you so much!