A player named Growltiger believes he/she has found what's causing the problem, and has even devised a fix that's seemed to work really well for the people who've tried it. Blizzard's acknowledged this and is working on patching the issue as soon as possible.
In the meantime, I thought that, in addition to including Growltiger's solution here, it might be a good idea to run an article on how to fix and prevent heat problems with Macs. We write for a pretty computer-savvy audience here at WoW Insider, and odds are good you'll find some people in the comment section who really know their stuff. I won't claim to be one of them, but I hope some of the things that have worked for me will also work for you.
Even if you're a novice computer user, you should find a few tips here. However, if you're one of the players looking to implement Growltiger's fix, fair warning: It's not for the faint of heart.
Let's get this out of the way right now: You are playing a game on a computer that was not really designed to play games.
Macs are good at lots of things, but this isn't one of them. If you run to the Mac Technical Support forum and scream and shout about how Blizzard's wrecking your computer, that is the wrong way to handle this. Blizzard is one of the few game companies that is willing to support the Mac, and they don't have to do that. That doesn't excuse them from ignoring any issue that's causing severe problems for a platform they officially support, but they are not sitting in Irvine, chuckling and rubbing their hands together as they hear the sound of a thousand Macs frying to death.
A very important disclaimer
The suggestions I'm going to give you below in addition to Growltiger's fix are what have worked for me over the last five years. However, it's extremely difficult to give specific advice for every Mac model, and some of these options I would not recommend for all users. I've divided them into easy, intermediate, and difficult fixes and tried to point you in the direction of more specific help where necessary. Ultimately, Google is your best friend. If you haven't had any heat problems until 5.0.4 and you just want to see what Growltiger did, skip ahead to the advanced section.
If you're not comfortable rummaging around your computer's guts or code and aren't willing to risk the possibility of something going wrong, don't do it. Just take a trip to an Apple store or an Apple-certified technician. As far as I'm aware, you also void your AppleCare contract or warranty by damaging your computer in the course of doing your own fixes, so keep that in mind. WoW Insider is not responsible for whatever you do to your computer trying to fix it.
Having said that, getting into your computer's innards isn't as tough or scary as it sounds, and it's always good to learn more about your machine and how it works. Apple has a full set of instruction manuals for each of its products to walk you through the basics of replacing hard drives or adding RAM. If you can do that, you can easily manage most of the suggestions here.
Easy fixes and how to prevent heat problems before they start
These are very, very basic and will not require any real knowledge of your computer or WoW commands. As a matter of fact, you should probably be doing at least a few of these no matter what just to keep temperatures down.
- External fan Keep a small fan trained on your computer while you're playing in order to keep cooler air circulating around your laptop. Keep in mind that this can produce background noise while you're on Ventrilo/Mumble/Teamspeak depending on placement.
- Don't play on any surface that's going to make the heat problem worse Don't play on bedspreads, blankets, or anything that's designed to trap heat.
- Use a cooling pad or a cooling stand There are lots of cooling pads/stands out there specifically designed for Mac laptops. I don't feel comfortable recommending a specific brand, but I will also note that you can even build one yourself very easily.
- Keep your vents clean Dust bunnies trap heat like it's their job. If your vents are full of muck, heat isn't getting out.
- Don't play in an overheated room Not surprisingly, your Mac will run hotter in a hot room and cooler in a cool room.
- Don't run anything else while you're playing WoW Everything you've got running in the background is one more thing your computer has to do while it's already running WoW. If you install smcFanControl (see below), you'll quickly get a sense of which programs or sites are most likely to spike high temperatures. Two of the most common are (unsurprisingly) YouTube videos and Netflix.
- Sacrifice the game's higher settings The game's higher-quality water, sunshafts, and shadows are all really cool, but you don't need them to play. Hit your System menu and scale back your settings.
Somehow, I don't think you're reading this article because the simple stuff worked. Let's move to the options that are more likely to make a serious difference.
- Cap your framerates This will make an enormous difference. The usual recommendation is to lower your framerates to 30, but I've taken it as low as 25 without its having a serious impact on play. (Don't get me wrong -- playing at 25 FPS won't make the game look as good as it does even at 30, but it'll probably knock off another five to 10 degrees.) In the game's chat log, type /console maxfps 30 and hit enter. You won't get a confirmation, but if you're running a mod like Titan that allows you to see your performance settings, you should see the FPS immediately drop to 30. If you play WoW windowed or tab out frequently, you should also do /console maxfpsbk 3 (or another tiny number), which will limit the game's FPS when it's not your primary application.
- Crack the computer open and clean your fans Your fans aren't going to do you any good if they're covered in dust or struggling to vent air through dust bunnies, and this will be a much bigger problem if you smoke, live in a home with people who do, and/or have pets. To get into my 2009 model, I use a #00 Phillips screwdriver and a T6 Torx screwdriver; your model may differ. You will also need compressed air. The screwdrivers and the air should be inexpensive. Use Apple's instruction manual or Google to find a guide on how to get into your particular machine.
- Delete (or move) the Cache, Interface, and WTF folders in your WoW folder I have no idea how or why this works, but I assume it's because your computer's going nuts trying to sort through a mass of increasingly elderly data and settings. Don't worry about screwing up your game; if WoW doesn't "see" these in your folder while you're logging in, it will simply make new ones. Warning: You will lose your addons and their settings when you do this, so you may just want to move all three folders to the desktop if you want to figure out if a particular mod's at fault.
- Download smcFanControl and iStat Nano smcFanControl is a program that allows you to manually crank your computer's fans while you're doing something CPU-intensive. iStat Nano is a small widget that will allow you to monitor the temperatures of different portions of your computer. A new version of smcFanControl just came out that supports both Mountain Lion and the new retina display Macs. Create a high RPM setting and shove your fans to the max before or immediately after you enter the game.
- Max your computer's RAM This won't actually fix heat problems per se, but it will mean that WoW won't slow everything else on your computer quite so much. And hell, if you've acquired the technical expertise to clean your notebook's fans, installing additional RAM will be easy.
- Pull out your battery This will significantly cool your computer. However, I don't think it's an option with every model. I could do this with my 2006 machine, but couldn't with my 2009 machine. Again, Google is your friend here.
This is where things start to get scary, but the payoff is significant when it works. This is also where you'll find the fix suggested by the player Growltiger in the 5.0.4 Performance Issue (Similar to D3 Beta) thread currently stickied in the Mac Technical Support forum.
- Replace your thermal paste This is probably not the real problem if you're running one of the more recent Macs. However, the misapplication and overuse of thermal paste was a major problem with 2006 and 2007-era MacBook Pros. (Having said that, if you're still running WoW on a 2006-era MacBook Pro and your house hasn't burned down yet, I would love to know how you're doing it.) Once again, you will need to Google for a guide on how to do this with your specific model. Doing this with my 2006 MBP was by far the scariest thing I have ever done with a computer barring the day I visited a My Little Pony: Friendship is Magic fan community.
- Replace your fans I have not gotten to the point of having to do this, but if you're hearing an odd sound from your fans, it's entirely possible that your heat problems lie with them. Again, how you do this will vary substantially by model.
- Growltiger's suggestion The player Growltiger believes the source of the 5.0.4 Mac heat problems lies with a single thread that's running GetBattlenetAllocator() and gobbling system resources. He was able to stop it using Xcode, with a description of how he did it spread over three comments here, here, and here. However, as he warns, while stopping the thread doesn't seem to have any immediate consequences, it may have some effect on Battle.net's function within the game down the road. We don't know what the thread is actually doing.
What to do if nothing works
If you've tried all of this stuff and your computer is still boiling itself to death while running WoW, then there are really only two possibilities left.
- The first is that your computer just doesn't have what it takes to run WoW anymore and you need a new one if you really want to keep playing. If you're planning on sticking around the game for a while, a desktop is far more likely to weather the big changes than a notebook, and you'll have the added advantage of being able to upgrade its parts more easily.
- The second is that the problem's on Blizzard's end and there's nothing you can do about it until they fix whatever's causing it. This happened with both Diablo III and, I believe, some quirk with Airport Express in 2010 that also caused Mac temperatures to skyrocket.
- Key specs
- Type All-in-one
- Screen size 27 inches
- Bundled OS Mac OS (Yosemite [10.10])
- CPU family Core i5
- Processor speed 3.5 GHz
- System RAM 8 GB
- Hard drive(s) 1 TB (total)
- Released 2014-10-20
Apple MacBook (early 2015)
Apple MacBook Pro 13-inch (early 2015)