Emulating Zelda – Breath of the Wild with Cemu
In this guide I am going to explain how you can install the Wii U emulator Cemu and run Zelda using it.
- Updated on 4th of August for Cemu 1.9.0c. The screenshots still show an old version but the instructions apply to the new version.
- You should already have a legal copy of Zelda in a Wii U emulator format
- I am not going to explain how to do this since there are already sufficient tutorials available
- Depending on the copyright laws in your country you may also get the game in a proper emulator format online if you already own the game. Due to legal reasons I can not link to these sources
- At least 8 GB of RAM
- Windows 7 or 10
- There are reports that Cemu works on Linux with Wine but this guide will focus on Windows
- 16GB of RAM
- i5 CPU or comparable/better
- 3.5 Ghz should be sufficient, but more is better in this case
- A good GPU (e.g. GTX 970)
- Not as important as the CPU but it will help
What you should expect
Cemu is in active development and thus will most likely include crashes, lags and bugs. I personally think that Cemu has come a long way and that the game has been playable since version 1.7.4d, but you should not expect it to run flawlessly.
Our target is a 4k resolution because in Cemu’s case the resolution is not as coherent with the performance as one might think, but you may adjust this to your personal needs.
The emulator will be capped to 30 FPS. This is not a performance decision as the game is actually supposed to run at 30 FPS. Removing the FPS cap may cause issues.
If you are a Patreon (if you don’t know what this is, you are not) you will have received a copy of Cemu. Otherwise go to the Cemu download page and download the latest release. The emulator is in a zip archive and can be extracted to any folder (e.g. the Desktop or your Program Files).
Tweaking with Nvidia control panel
Open up cemu.exe and let in run in the background. Now open the Nvidia control panel (via the system tray icon or search for it in the start menu).
Choose “Manage 3D settings” and then “Program settings”. For program choose cemu.exe and set the following settings:
Graphic packs are a way for the community to change graphics settings and behaviour. They predefine things like resolution but may also fix minor glitches or improve effects like shadows.
There is a collection of graphic packs created by the community which can be found on GitHub. To download the collection follow the link, click on “Clone or download” and choose “Download ZIP”.
Extract the zip to it’s own directory. Inside you will find a lot of different folders for different games and categories.
If you have the recommended hardware I suggest using the “BreathOfTheWild_2160p” pack in the “Quality”-folder. If your hardware is not that perfect you can also use the “BreathOfTheWild_540p” or “BreathOfTheWild_360p” packs from the “Performance”-folder. If you are not sure, just go with the quality pack for now and you can still change it later.
Move your selected folder into the “graphicPacks” folder inside your Cemu directory.
For extra improvements also copy the appropriate packs from the “Enhancements”-folder to your graphic packs folder. There are a few more then when I made the screenshot below by now, but you can copy any enhancement you like. I used all except the “BreathOfTheWild_ProPlus” HUD enhancement. It caused graphic glitched for me and others.
Restart Cemu, choose “Options”, “Graphic packs” and choose all graphicPacks that you have just moved to your folder. You need to restart Cemu after this.
Make sure to update your graphic packs every once in a while since they get modified and improved regulary. To do this just download the ZIP again and overwrite the folders.
“Cemu hook” is a plugin for Cemu made by the developer “rajkosto” and allows playing video sequences with the H264 codec which are not yet supported by Cemu and a few other changes that are listed on the website.
To install the plugin just head over to his website and download the plugin version that fits your Cemu version. Extract the zip file and simply move the dbghelp.dll-file inside the cemu directory.
Firing up the game in Cemu
For the following steps we need to run Zelda so that some files are generated.
Just open Cemu, choose “File” and then “Load” and select your game file. This can be a rpx, wud, wux, iso or wad file. As soon as the game has loaded, close it again.
When you run a game in Cemu the emulator has to calculate a lot of things. Some of these have to be calculated once and can then be written into a cache that is to be reused by the emulator. This is good because not everything has to be recalculated but this also means that you get FPS drops the first time things like shaders need to be calculated – which is all the time.
The good news is that you can download the shader cache of other players so that your emulator does not have to do everything by itself. The bad news is that these caches are probably affected by copyright laws and thus I can not link to these files. For the possible case that you already own such a cache or stumbled upon it with something like a Google search, I will now explain how you can copy it into Cemu.
Ideally your shader cache should have somewhere between 5 to 10k shaders. More will cause excessive RAM usage and will take a long time to compile. Less will probably mean missing shaders that will cause FPS drops.
Shader caches are .bin-files for each game and in the newer versions of Cemu they have become transferable. All you have to do is to copy the .bin-file to your [Cemu folder]/shaderCache/transferable folder and replace the .bin file that has been generated in the previous step. It should have a string with letters and numbers as file name and it is important that you replace this file so that your new file has the same name.
Disabling Hyper-Threading for Cemu
This part will only affect you if you are using an Intel CPU with hyper threading – like i7-4960X. Otherwise you can just skip to the next step.
While Hyper-Threading should be beneficial, it can be bad for Cemu if important processes are not assigned to a physical core. To solve this we will change the processor affinity in the task manager.
Start Cemu and open the Task Manager. Switch to Details and find cemu.exe, right click it and choose Processor Affinity. In the following window uncheck every second thread. If you have 8 threads you should uncheck CPU 1, CPU 3, CPU 5 and CPU 7.
You will have to repeat this step if you install a new version of Cemu.
Finally you can start the game as described before.When you start the game Cemu has to compile your cached shaders. It can take a long time (10 minutes to an hour if you have up to 20000 shaders) when you are doing it for the first time, but from the second time on it should be loading much faster.
Make sure the GPUFence setting is enabled. Open “Options” and enable “GX2SetGPUFence skip (HACK)”. You may need to do this after every restart.
If you run into any problems, please check the troubleshooting section below. If you can’t find an appropriate solution there, feel free to ask for help in the comment section. You can also check Reddit or ask for help on their Discord server.
I suggest making regular backups as playing around with the emulator can destroy your savegames. Your savegames are located in [Cemu folder]/mlc01/emulatorSave. I would also appreciate a comment below about your hardware specifications and how well the game is running for you.
I will continue to extend this section as I stumble upon new common problems.
- The game crashes during or directly after starting the game and Windows tells me there is not enough RAM available.
- You can try to increase the file of the pagefile.sys. Instructions on how to do this can be found here.
- A big shader cache (>10k) might also be the problem. You can try to use a smaller one with 5-8k
- My shader cache is compiling extremely slow.
- This can have a number of reasons and in some cases is just the way it is. There are reports though that activating VSync in the Nvidia control panel does slow down the process. You can try to turn it off again and see if it works for you.
- How do I solve tasks which need the gyroscope?
- The gyroscope can be simulated with the mouse. It does not work nicely, but the tasks can be solved.
- The game crashes every few minutes.
- A crash every now and then is considered normal as of right now, but if it is happening every few minutes you can try a possible solution posted by MonteXMat on Reddit. For some users it seems to help.
- My games won’t save or load.
- Maybe Cemu does not have write permission for your save game folder. Try running Cemu as administrator (right click and choose “Run as administrator”).