Mac graphical slowdown (Starcraft 2)

Talka

I've been having a weird problem with my Macbook Pro.

When I play Starcraft 2, I'm capable of playing about five minutes on high graphical level settings. After that point, I get immense slowdown and the game becomes unplayable even on low graphical settings.

What might cause a game to slowdown like that after five minutes of play? I'm thinking maybe there's confusion going on with the two video cards the MBP is supposed to switching between, but I can't think of a way to see which cards are running when (I've enabled the option to always use the higher-end one, but who knows if that's happening).

Any ideas what might cause something like this?

Scosglen

Do you play any other games on the macbook that would similarly stress the system?

Dratatoo

You could use the program gfxCardStatus to take a look which graphic card is running. This tool also allows you to switch the GPU.

Secondly, make sure that you Macbook isn't overheating - otherwise it might throttle the CPU resulting in performance loss. (You can clearly hear the fans kicking in overdrive and becoming really audible) - flat surface gurantees that your machine doesn't heat up.

According to some reviews the Windows version of SCII is less problematic and has better performance. If you have Windows/Bootcamp installed it is worth a try.

Try avoiding tabbing out of the mac version, the game might show some odd behaviour (if this isn't patched already).

physi_marc

This is supposedly a known issue with the nVidia drivers in Mac OS X 10.6.4. Valve mentioned this issue when 10.6.4 came out and now we're seeing the same kind of performance dip in StarCraft 2. If you check the StarCraft 2 Mac support forums, you'll see tons of similar posts, so you're not alone. In fact, I experience the same thing on my brand new Core i7 MacBook Pro with 512 MB of VRAM.

Some solutions right now:

1) Downgrade to 10.6.3, but I wouldn't recommend it.
2) Wait for 10.6.5 which has just been leaked to developers and hope it includes a fix for this issue.
3) Install Windows with Boot Camp and download the latest drivers for your card.

The Windows option might be the best one if you want to enjoy the game on higher settings right now. Remember that you can install as many versions of the game on as many computers as you want, as long as you only log into your Battle.net account on one computer at a time.

DietarySupplement

It's most certainly a heat issue; those things really start to cook-off under heavy load. The machine is totally capable of cooling, but Apple has the fan controls locked down and to preserve noise and power usage. You have a couple options:

1. Bootcamp. Not because you have to (side note: I wish more publishers would release dual PC/Mac releases; I think with Steam we'll see more of this) but the drivers in XP/Vista/7 actually properly regulate fan speed and thus control temperature.

2. Grab a 3rd-party utility for manually setting your fan speed. I haven't tried this, but people say it works: http://www.lobotomo.com/products/FanControl/

Mangaroo

Heat is what came to mind, perhaps try SMC fan control

Brodo Faggins

I have a core i5 macbook pro, and smc fan control keeps me around 70 degrees celsius. It's still unplayable though, even on low to middle settings. Best bet is to wait for nvidia and apple to properly update the drivers, or install BootCamp.

Talka

Very helpful everyone, I've got it running fine in BootCamp now.

Drunk_caterpillar

I'm going to assume that you're running one of the 2009 Macbook Pros, so I'll share my advice. I was having similar problems in SC2 and pretty much every other game on my system. Wanna know what solved it for me?

Switch to the Geforce 9400m.

Maybe there's a memory leak with the 9600 GT drivers or something, but for one reason or another the lower end graphics card in my Macbook Pro is rock solid. I have to keep the settings low but the FPS count is higher and more stable than my 9600 GT was on low settings. I'm hoping that Apple/nVidia fix this post haste, because it looks much better on the 9600.

Dratatoo

Are you able to play SCII with the 9400m? On my Alu Macbook (2008) I am not able to get anything which resembles playable, even with low settings (Windows 7) - I have the most expensive configuration - Core 2 Duo 2,4 GHz. Well, I only tried the Campain Map "Devil's Playground" which is very demanding I think.

This has been the case for any games which make lots of use of Pixel Shaders (3.0). Noteable exceptions are Team Fortress and HL2.

Drunk_caterpillar

Yeah, on low settings my 9400m works very well. Consistent and smooth with low settings. Haven't had a single hiccup. Mind you, I've got a 2.53 GHz C2D with 4GB RAM so your milage may vary.

Dratatoo

Did you set everything to "low"? - Does the 9400 in your machine use shared memory?

Drunk_caterpillar

Yep and yep.