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Ice Dragon

macrumors 6502a
Original poster
Jun 16, 2009
989
20
I know it is probably too early to ask though perhaps not. How much memory does the Iris Pro graphics take from the main memory for 8 GB and 16 GB?

Thanks in advance.
 
Excuse my ignorance, but does this mean there is not as much RAM (of the 8 GB) available to OS X because Iris Pro is using 1 GB of it?

Whereas, on the 2012 model there was a dedicated graphics card and so the full 8 GB RAM was available to the system.

For example, on my 2012 iMac OS X 10.8 used around 1.4 GB of wired RAM for the OS. Will this now jump to 2.4 GB because 1 GB is reserved for Iris Pro?

Do this also mean potentially that if one uses programs that are uses a lot of RAM it might push the machine more to the limit as you near say 7 GB RAM usage?

Thanks
 
Excuse my ignorance, but does this mean there is not as much RAM (of the 8 GB) available to OS X because Iris Pro is using 1 GB of it?

Whereas, on the 2012 model there was a dedicated graphics card and so the full 8 GB RAM was available to the system.

For example, on my 2012 iMac OS X 10.8 used around 1.4 GB of wired RAM for the OS. Will this now jump to 2.4 GB because 1 GB is reserved for Iris Pro?

Do this also mean potentially that if one uses programs that are uses a lot of RAM it might push the machine more to the limit as you near say 7 GB RAM usage?

Thanks
you are more or less correct. When the gpu needs to use 1GB of vram then there will only be 7GB available for the system.

have a read here: http://forums.cnet.com/7723-10149_1...ry-confusion-dedicated-shared-discrete-oh-my/
 
Thank you for the reply. In the link you provide it states:

"Sharing main memory with the display function reduces the amount of memory available to applications, and main memory is not as fast as the specialized video memory on stand-alone cards."

I'm assuming, however, that Iris Pro even though it's using shared memory will not be slower than the base dedicated NVIDIA card in the 2012 iMac?
 
Thank you for the reply. In the link you provide it states:

"Sharing main memory with the display function reduces the amount of memory available to applications, and main memory is not as fast as the specialized video memory on stand-alone cards."

I'm assuming, however, that Iris Pro even though it's using shared memory will not be slower than the base dedicated NVIDIA card in the 2012 iMac?

No, the Iris Pro is faster. I think someone told me by at least 10-15%. Also thinking with the old Steve Jobs idea of "performance per watt", there was not enough to consider having 1 GB of the 740M in the base model or worse 512 MB of the 750M.
 
Iris Pro 5200 also has a 128MB cache for graphics only. It is located on the CPU die.
 
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