First start of the day of my baked Pixel Streaming project is slower than the next ones. What is happening?

Development Platform & Builds
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1

So I noticed this behavior where the first execution of my baked UE5.3 project (pixel streaming app) on a new EC2 virtual machine takes roughly 3 to 4 minutes to reach the “Game Engine Initialized” point (worst case I’ve got), whereas, for the subsequent executions, it’s instant.

I wonder what is happening if this is a cache kind of thing behind the scenes, and maybe I can “pre-bake” this process as well?

Notice the timestamp difference between:

First start:

2025.03.11-19.56.47:356][  0]LogRemoteControl: Display: Web remote control is disabled by default when running outside the editor. Use the -RCWebControlEnable flag when launching in order to use it.
[2025.03.11-19.56.48:363][  0]LogAudioDebug: Display: Lib vorbis DLL was dynamically loaded.
[...]
[78 seconds later...]
[...]
[2025.03.11-19.58.06:234][  0]LogInit: Display: Game Engine Initialized.
[2025.03.11-19.59.06:254][  0]LogCUDA: Display: Initialising CUDA API...

Second start:

[2025.03.11-19.59.14:394][  0]LogRemoteControl: Display: Web remote control is disabled by default when running outside the editor. Use the -RCWebControlEnable flag when launching in order to use it.
[2025.03.11-19.59.14:698][  0]LogAudioDebug: Display: Lib vorbis DLL was dynamically loaded.
[...]
[5 seconds later...]
[...]
[2025.03.11-19.59.19:901][  0]LogInit: Display: Game Engine Initialized.
[2025.03.11-19.59.19:921][  0]LogCUDA: Display: Initialising CUDA API...

I appreciate any guidance to troubleshoot it!

2

Yes, that’s correct. When the .exe is launched for the first time, it creates cache files and stores them in the C:/User/YourUsername/App Data/Local folder. This process can be CPU-intensive because it involves shader compilation and other initialization tasks. If you’re using G4 or G5 instances, the limited CPU cores may lead to longer load times.

To optimize this, you can pre-bake the cache files in the same C:/User/YourUsername/App Data/Local folder during the creation of the EC2 instance. This eliminates the need for the game to generate the cache during the first launch, giving you a faster startup.

In our case, we switched to Streampixel. Initially, we used AWS, but we found Streampixel to offer better-performing machines at a lower cost.

Hope this helps!