What does Steam download when you "verify integrity of game cache?"

[heehatatt]

Title says it all. Some of the times I've verified it's downloaded a couple of gigabytes, other times its downloaded a couple of megabytes.

Is it harmful to a modded Skyrim? Is it harmless?

[Ventus2111]

It downloads missing files. For example, if you're missing Skyrim.exe, Steam downloads this file.

It's not good to do this on a modded game. If you cleaned the .esps, Steam will download them again. The same thing can happen to other files. So if you do this, Steam might replace your modded content with the vanilla files. Don't do it.

[Guest]

It downloads missing files. For example, if you're missing Skyrim.exe, Steam downloads this file.

It's not good to do this on a modded game. If you cleaned the .esps, Steam will download them again. The same thing can happen to other files. So if you do this, Steam might replace your modded content with the vanilla files. Don't do it.

 

Or you can let your Mod manager to handle the "replaced" files, and rely on Steam to have always the game running.

 

The logic of Steam cache integrity is more or less this one:

For each file that is supposed to be in the game, its checksum (it is a variant of the blake2 algorithm) is generated.

Then steam verifies that the resulting checksum corresponds to the actual latest released version for the file.

In case it is different the file is re-downloaded.

 

Now for a set of games (not all of them), the check is not done for the whole file, but for some sort of "blocks" of the file.

So in some cases, only a part of the file can be re-downloaded.

(Very few games support this behavior.)

[heehatatt]

 

It downloads missing files. For example, if you're missing Skyrim.exe, Steam downloads this file.

It's not good to do this on a modded game. If you cleaned the .esps, Steam will download them again. The same thing can happen to other files. So if you do this, Steam might replace your modded content with the vanilla files. Don't do it.

 

Or you can let your Mod manager to handle the "replaced" files, and rely on Steam to have always the game running.

 

The logic of Steam cache integrity is more or less this one:

For each file that is supposed to be in the game, its checksum (it is a variant of the blake2 algorithm) is generated.

Then steam verifies that the resulting checksum corresponds to the actual latest released version for the file.

In case it is different the file is re-downloaded.

 

Now for a set of games (not all of them), the check is not done for the whole file, but for some sort of "blocks" of the file.

So in some cases, only a part of the file can be re-downloaded.

(Very few games support this behavior.)

 

 

Well, knowing this my next question is, did it harm my game? I'm running a crap ton of mods, at 254 extensions. Texture mods, lighting mods, etc. etc. Is there any way to know which files steam replaced? This might just me being paranoid but it seemed like there was an fps drop after verifying.

[Guest]

Only original files are replaced. "Etxtra files" are not touched.

But you may miss your "plugin list" or "load order" because it may be replaced (it does not happen always, but in some cases it happens.)

 

If you are under the wing of Mod Organizer, you should not care less about impacts, because all your mods are not in the vanilla game folder.

[bjornk]

 

 Is there any way to know which files steam replaced? This might just me being paranoid but it seemed like there was an fps drop after verifying.

 

Steam client may only replace the official game files inside the SteamApps\common folder (EXE, DLL, ESM, BSA, INI etc.). To see what has been replaced, you may open that folder in Explorer and search for files that were created on the date you ran the verification (e.g. write datecreated:01/08/2016 on the search box).

[heehatatt]

Only original files are replaced. "Etxtra files" are not touched.

But you may miss your "plugin list" or "load order" because it may be replaced (it does not happen always, but in some cases it happens.)

 

If you are under the wing of Mod Organizer, you should not care less about impacts, because all your mods are not in the vanilla game folder.

Welp, I'm a dirty NMM plebeian. In the end it looks like all it did was re-download the base games .esm files and screwed my load order.

[gregathit]

Yes, it can jack with your load order, as it changes the date stamps of any file you download.

 

If it was not mentioned before, in addition to downloading "missing files" it downloads any file that isn't the correct "size".  Thus, if you downloaded and installed a mod that changes the vanilla files (high resolution textures/meshes) and they replace the original files, then it will get deleted and the vanilla will be put back.

 

It is always best to check mods to see what they are installing, and avoid mods that actually fuck with the vanilla game files.  That isn't necessary to do with all the tools that are out there.

[malvekiar]

If you verify the integrity of the game cache after having cleaned the masters, you will want to do this again.  If you aren't cleaning your masters (using TES5Edit), you probably should be.