I'm posting this here because I can not seem to find a dedicated Witcher 2 or CD Projekt Red forum, so I guess this is as close as I'll get to reaching the appropriate audience.

Why do Steam users need to re-download almost the entire game in order to patch it?
Your company rightfully prides itself on being consumer-friendly. You deliver great products and do not force your users to jump through hoops in order to use them.
You won me over with your concept of DRM free games and re-bought many games I already owned as retail copies from GOG because I chose to support you as best as I could.
I was and still am a great fan of GOG and also of the The Witcher series.
But what motivated you to treat Steam customers so poorly? I didn't think you'd treat your customers differently just because they bought your product through a different platform, but I'm beginning to wonder what's going on between you and Steam.
First there was no preload on Steam, which I guess made playing on release day impossible for most people with slower internet connections.
Now, for the second time, Steam users have to download a 9Gb file in order to update their game while GOG customers get their patch served in a handy <100Mb package.
Why would you do that?
It doesn't even impact ME all that badly, I have a fairly fast 12Mbit connection and thus the download will only take me under two hours, but this is just unreasonable no matter what type of internet connection you have.

Please, change the way the game is patched on Steam, if not right away, do it for future patches.
This is causing a lot of confusion among your customers, and as far as my understanding of the technical side goes, for no good reason at all.

Kind regards

Shouldn't it be Steam in charge of the patch distribution? Wouldn't know why CDP would make people redownload everything.

From what I gathered, correct me if I'm wrong, Steam doesn't decide how the game is patched, they only distribute the modified files given to them by the developer.

Oh, that's strange. Might want to duplicate your message in The Witcher 2 board.

It's the way CDP implemented the updater system that is wasn't compatible with steam's auto-patcher. That's the downside to steam's system where it's totally steam controlled.

CDP are said to be working on it so that the game can be updated normally on steam in the future. This issue's been discussed on steam's Witcher 2 forum. You're much better off posting in that forum than GOG's forum.

I'm guessing it's to do with the game file structure. The normal patch probably does just that: Patches some of the files. If the way Steam works is to download the changed files it might redownload the entirety of any file that was changed in the update. If this is the case, it's Valve's fault for not making Steam deal with patches properly.

According to a user on the Steam forums:

Steam has the ability to only copy deltas (changes in files), so there's no reason for the entire game to be re-downloaded.

So I do not understand why updating only the relevant files within the dzip shouldn't be possible.

Well (from the steam Witcher 2 forums)

Every other version of the game whether it be retail or digital distribution can edit files during the patch process while Steam is the only one which cannot thus requiring entire re-downloads of the newer files. CD Projekt isn't and shouldn't have to redesign their entire file structure for the game because Steam is backwards.

pack0.dzip has to be redownloaded entirely because it houses the information that calls on the actual new content files like troll.dzip, swordsman_suit.dzip, ct. so they will be available in the game. What a actual patch program does is goes into the directory and adds/deletes file paths to new things while adding the content that's new. Steam doesn't do that it replaces the entire file if it's modified and gets the new content.

http://forums.steampowered.com/forums/showpost.php?p=22782319&amp;postcount=8

So it is steam's rigid patcher system causing the issue

That's what I suspected.

I somehow can't believe that Steams updater cannot make incremental updates? Just applying diffs/deltas sounds like the obvious must have feature for any auto-updater.

The Steam software may be capable of this, but steam doesn't patch anything that way. It does a hash check against the local content and if the file fails the check it downloads a new copy of that file. If the file was altered due to a patch the file on the server will have a different hash making all older versions of the file fail the check.


One would think... but every game on steam has this problem. If a file is changed it does a check on the hash and if the local file is different Steam downloads a new copy of the file.

I honestly doubt this is specific to Witcher 2. I know it happened to me with a completely different game (warhammer 40k dawn of war II).

Some people on steam where lucky enough to net a small 4mb patch, but a select few of us where being forced by steam to download gigs of 'patch' data.

Despite all attempts to recheck game cache, and reinstalling from a complete steam backup of the game, steam insisted I (and a few others) download gigs of data when the official disk version patch was a few megabytes.

I would hazard the fault lies with the steam patching process. If a new patch arrives that doesn't play kosher with your particular game region + version you can be hit with a giant 'patch' that fixes errors exclusive to the steam version for your region.

I'm with the explanation of Steam downloading the whole changed files again.
Even if it could do incremental updates, it'd need to do checksums of all your files, and keep those checksums for all versions for every single patch version. It's not certain you have steam open every time there's a patch released, so for an often patched game it might then need to figure out which version you have, run the patcher for each of the versions between then and here and then hope the things went well and it's got the correct version.
Also I'd hate it if that was the only way steam would work. Think of downloading Team Fortress 2 and you get the initial release of it on your computer, then it's just update after update after update after update after update.

That being said, I'm sure there's some delta patches going on at times too, at least on valve games. It seems every time there's an update for Team Fortress 2 or Left 4 dead put on my computer, steam will eat up all the HDD IO it can get close to for minutes at a time. I've got a quad core 2.5ghz computer with 4gb of ddr ram, and yet, occasionally not long after starting steam my computer can be locked up for up to 10 minutes, not just steam, browsing in firefox will be almost at a standstill, opening the start menu taking 10-15 seconds. And then suddenly my computer will move fast again always coinciding with a popup saying Steam has finished updating something like Team Fortress 2 or Left 4 dead or something.
If it was just replacing an old file with a new file it shouldn't lock up my computer, it very rarely does with non-valve games when they get an update through steam.