I've got the GOG version of the game. I used to sometimes get little freezes of ~1 second when knifing someone with the hidden blade, but they were so trivial that I never even remembered to google for a solution.

However, after I recently updated my Nvidia drivers from version 285.62 to 306.23, AC started freezing repeatedly for about ~5 seconds a time, often during loading transitions, but also when knifing people or just randomly during gameplay. A little bit of googling shows that it seems to be related to the game trying to communicate to Ubisoft. I tried blocking the game using Eset Smart Security, but it made no difference, whether using a custom or auto-built rule or simply blocking all traffic. Disconnecting my computer from my router, however, fixed the problem.

What I don't get is the fact that it only became a problem after updating my drivers. I ended up uninstalling the 306.23 drivers and reinstalling 285.62, as they also caused Dawn of War to stop working, despite the release notes for the driver saying that they had worked around this issue. Downgrading got DoW working again, although the same issue is reported in the release notes for 285.62! Unfortunately the trouble with AC persisted, even after reinstalling the game, until I tried disconnecting from the internet.

Specs:
OS: Windows 7 Ultimate 64-bit
Processor: AMD Phenom II X6 1100T 3.30 Ghz (6 core)
Ram: 8 gigs
Video card: GeForce GTX 560

The annoying part is I don't want to disconnect my machine entirely. Even advanced firewall rules (inbound/outbound) don't work to alleviate the problem. I don't see why the freezes got aggravated after a driver update, but you've come to the right conclusion, apparently the game saves at those freeze points and tries to communicate to their servers. Which is an annoying feature, seeing as we're on a DRM-free version which isn't tied to the Ubisoft Downloader. I hope there's a friendly fix -or patch- for disabling this useless feature. Apparently those using the Ubisoft software to play this can disable the online saves via a settings configuration file on the downloader, so I'm not sure how us GOG-version users can do this. The constant freezing is a nuisance and makes me want to just not play this game.

EDIT: I dug through some Steam boards and found a perfectly viable fix (don't know if it's permanent though, they needed to add another IP address this October.)

http://steamcommunity.com/app/15100/discussions/0/864947740591808974/#p2

Post #18 is where it's at. Please tell me if linking out is not allowed, thanks. Hope this helps.

I'm having the same issues and nothing seems to help.

Spec
Intel i-7 3.2ghz
18gt ram
Gefoce 560GTX TI
Windows 7 Professional 64bit

What have you tried? With your specs it shouldn't be a hardware problem.

I tried
1. Downgraded drivers -> didn't work
2. Re-installed the game> didn't work
3. Disabled the internet > didn't work
4. Uninstalled my video / audio codecs > didn't work

I even installed AC to my 60gb SSD and i got the same results, so i have no idea how to get this game to run smoothly on my computer.

Also i recorded a video of
http://www.youtube.com/watch?v=DsOLxNdXylM&feature=plcp

At least for me, this game is broken :/

Looks like the same problem I was having. Did you try the hosts file thing outlined in the link I provided? I'm on a laptop and I had to disable the internet connection by actually disabling the WLAN card (which really irked me so I looked for another way.)

Yes i tried and it didn't work for me, and i'm still wondering why you should disable the internet connection for a game that is supposed to be DRM-Free.

I never had this problem with any other game and at least i'm not buying more Ubisoft tittles from GOG.

Yeah I'm pretty miffed they overlooked this aspect of the former Ubisoft DRM. Sorry I can't help you though. Here's hoping that something can be done.

Hello

I have exactly the same problem here.
Disabling my ethernet card has solved the problem but wtf you had to be online all the time to play this game with drm and now you have to be offline permanently without drm...
This game should not be sold in that state.

My Specs: i7 2600k + P8Z68 Deluxe MB + 8gb ram + 560ti + Win7 pro 64bit

Regards.

Never had any trouble with AC while being online. However, do take a look here and update your drivers accordingly.

I use the latest official nVidia drivers, version 306.97 WHQL for my GTX560Ti and I suffer from the freezes if I'm online. Any other suggestions (other than going offline while playing)?

Roll back your drivers. This is a problem due to NVIDIA drivers, not due to GOG.com
My 315M (or something like that) didn't have any troubles, but it doesn't have any newer drivers either. Alternatively, see if you can block nvidia from accessing the internet, but not sure if it will help or not.

I don't think this is about nvidia drivers, i have the 306.23 installed with the same problem. The game is working but it freezes 2 or 3 seconds every time you do specific actions (kill, taking flags, autosave...) exactly like in Terpor's video. Which prove that the game is faulty.

Blocking everything nVidia with a firewall didn't help. The weird thing is, that the solution mentioned in the steam forum with changing the hosts file only blocks access to IPs from Ubisoft servers. What do nVidia drivers have to do with Ubisoft servers? Maybe the newer drivers are somehow optimized in a way that triggers DRM or some anti-cheat prevention or something in AC and then AC tries to report this to the Ubisoft servers and this freezes the game temporarily.

edit:
Also there's somebody reporting similar problems with an ATi graphics card here:
http://www.gog.com/en/forum/assassins_creed_directors_cut/assassins_creed_crashes/post3

I found this topic to be quite interesting
http://forums.ubi.com/showthread.php/717165-Game-hangs-all-of-a-sudden/page3

Also someone posted a reply from the support and it's quite odd
Unfortunately, this game is not supported for use on Windows 7. First, please make sure that you have the latest drivers installed for your video and sound card. Most problems with Windows 7 are related to using outdated hardware drivers. You may be able to run the game in compatability mode, but the only other recommendation that we could make for you would be to install and play the game on a computer that meets the requirements listed on the bottom of the game's box. Thank you for your understanding in this matter. I would recommend disabling your internet as you play the game and seeing this may help resolve this issue. I'm very sorry for the inconvenience!