Owners of dual graphics card MBP (or anyone that knows...)

[carlosbutler]

After thinking that when running in Mac OS X the MBP would run both graphics cards when playing games, i have not been told it doesnt. But it does when running XP. is this because there arent decent drivers out from nVidia or what? or am i being told a lie.

i only wonder because i was thinking of upgrading from a 3year black macbook to a 15" MBP, but was not sure about the graphics

 

[rdowty]

You basically pick either the integrated or discrete graphics in energy saving settings when you're in OS X.

In BootCamp you will be always using discrete graphics and there's no way to change it that I know.

 

[J the Ninja]

Yes, you choose one or the other in OS X. It's possible that with Snow Leopard it will be able to switch between the two on the fly, possibly even automatically, but we don't know for sure yet.

As for Windows, using either the provided Boot Camp driver or the one of Nvidia.com, it will just lock to the 9600M GT, you cannot use the 9400 for anything. BUT! It is possible to switch between the two on the fly in Windows as well, but it takes some messing around with drivers.


You cannot use the two at the same time. That is called "GeForce Boost". It is essentially vanilla SLI, but between the integrated and discrete GPUs, rather than two discrete ones as it normally is. As with all SLI setups, using two different GPUs in a pair will cause the more powerful one to downclock and shut down cores until it is equivalent to the lower power one. Considering that the 9600M is already basically two 9400s stacked together, there wouldn't be any benefit to this. You'd essentially be tearing out half your GPU power to replace it with the same thing, except the replacement half has no dedicated memory. So, the 9600M doesn't support this.

 

[carlosbutler]

Ok. That is for the help on that. So I presume that the battery life with windows loaded is a lot lower because you always have the 9600 running then?

 

[the advisor]

yes

much lower.

 

[arfle18]

As for Windows, using either the provided Boot Camp driver or the one of Nvidia.com, it will just lock to the 9600M GT, you cannot use the 9400 for anything. BUT! It is possible to switch between the two on the fly in Windows as well, but it takes some messing around with drivers.

Hey J -

How does one do this? The short battery life on Win XP with the 9600 card is driving me crazy. So frustrating, when the Mac side lasts 3 times as long using the 9400 card.

Thanks!