World of Warcraft 5.0.4 – Heating Issues and the Mac

World of Warcraft 5.0.4 went live last week, the 28th of August. A lot of Mac users starting noticing that their Macs were running hotter than normal after patching. However, more than a few Windows/PC players are experiencing the heat issue, and so it doesn’t appear to be related to any changes in the graphics code or Mac-specific coding, and it may have even been narrowed down to a single thread on both platforms, as Blizzard support has released a fix for beta users around 10:30pm CST. Retail users will have to wait a little longer.

As somebody who follows Blizzard’s World of Warcraft Mac Technical Support Forum quite a bit, and as a Mac user who plays World of Warcraft a few times a year (this time being one of them), I noticed it. I just haven’t had a chance to sit down and do any debugging or trying any of the solutions presented by players.

I took a look at WOW Insider yesterday and noticed they had a good article up on it, soliciting feedback from Mac users over the issue.

It should be noted that most players who are noticing the heat issue, are playing WOW on MacBooks and MacBook Pros (and a few on MacBook Airs). It’s a Mac issue in that Apple’s unibody design can make the heat more noticeable when you are gaming on one of the portables, the same as if you are doing some heavy video editing – the CPU is working hard and the heat is being generated.

The heating issue can happen even while sitting at the login screen, and that’s a problem for everybody. My Mac is normally extremely quite, and I can tell it’s heating up when the fans rev up, but it definitely should not be doing so at a login screen.

The cause has most likely been determined as being related to a certain thread running at 100%, GetBattlenetAllocator(). A player going by Growltiger noticed the thread and has posted a solution. Blizzard has acknowledged the issue and a possible fix:

I just want to acknowledge the issue raised by Growltiger, a fix will be included in a future patch. We will do our best to deliver this patch asap when it’s ready. We are sorry for the inconvenience that this is causing.

We hope that this will solve the overheating issue but we can’t be sure since we have problems reproducing that issue.

A few hours ago, this was posted by Blizzard support.

Linean, a retail patch is currently being tested. If you have access to the beta then you can verify if it works since a beta patch with the fix was released today.

Retail patches require a lot more testing since they affect a lot more customers.

WOW Insider put together a list of common-sense things that can help with the heat – be careful of where you play (no MacBookss on a blanket in bed), keep a good amount of air circulation, active or passive, around your Mac. Be willing to sacrifice some of the high-end settings is another good bit of advice, especially on older Macs until they issue a patch that fixes this.

As far as WOW-specific short-term fixes, I can vouch for capping your framerate. “/console maxfps 30” can make things run considerably cooler depending on your Mac and where you are at in the game.

Those things only address the symptoms though, they don’t address the root cause of what’s generating the heat. They do point you to some posts made by the afore-mentioned Growltiger about using Xcode to stop a certain thread related to that is running in the client. This is a pretty serious solution, and if you know what you are doing, it can fix the problem, but nobody knows the consequences, whether it will affect and anything your client sends to it. If you are willing to go that far, another player has posted a simpler version of what Growltiger was talking about.

I can verify that stopping the thread dropped the CPU usage/heat, but it’s not something I recommend to everybody, and I had to do it again when I started WOW later on in the day. I would cap your framewrate and turn your settings down first and see how much it helps. If you are knowledgeable enough, or brave enough, the instructions for dealing with the wayward thread using Xcode are in the previous paragraph.

You can follow along in the 5.0.4 Performance Issue (Similar to D3 Beta) thread that has been stickied by Blizzard support staff.