intel 4000 vRAM question.

Techno Pirate

macrumors newbie
Original poster
Jul 29, 2012
14
0
I have the 2012 baseline 13in June macbook pro with 4gb and an i5. I checked out the my intel 4000's vRam and it says 384mb where as the beefier i7 model with 8gb at the apple store reported 512mb of vRAM. That's a pretty large difference in certain applications, performance wise, so I wanted to make sure of something. Is it true that If I upgrade my ram from 4gb to 8gb the vRAM the intel 4000 borrows goes up to 512mb from 384mb? I remember that happening in one of the previous macbook pro models with a different intel GPU. Or maybe it's only in the i7 model. Thanks

Al
 

gentlefury

macrumors 68030
Jul 21, 2011
2,848
0
Los Angeles, CA
I have the 2012 baseline 13in June macbook pro with 4gb and an i5. I checked out the my intel 4000's vRam and it says 384mb where as the beefier i7 model with 8gb at the apple store reported 512mb of vRAM. That's a pretty large difference in certain applications, performance wise, so I wanted to make sure of something. Is it true that If I upgrade my ram from 4gb to 8gb the vRAM the intel 4000 borrows goes up to 512mb from 384mb? I remember that happening in one of the previous macbook pro models with a different intel GPU. Or maybe it's only in the i7 model. Thanks

Al
Yes, the more ram you have the more vram you get. Apple limits the hd4000 to 512MB which is reached at 8gb.
 

yusukeaoki

macrumors 68030
Mar 22, 2011
2,550
6
Tokyo, Japan
Yeah it would be cool if more RAM= more VRAM but thats not how it works.

4GB is 384MB, 8GB and above is all 512MB.

This is same with the old intel HD 3000
 

tmt

macrumors member
Mar 8, 2009
84
13
Sorry to hijack the thread but why is the intel gpu limited to 512 mb? I was looking forward in putting in 16 Gb into mine ;)
/J
 

dusk007

macrumors 68040
Dec 5, 2009
3,386
61
Because it is not really fast enough for a detail level that would require more VRAM anyway.
Also since it has no dedicated RAM access to System memory is much less troublesome for the HD 4000 than for say 650M.
It has full speed access to the LLC aka L3 and the copy path from to memory is full speed low latency (direct). There is no latency problem or limited bandwidth as the x8 PCIe lanes pose. A 650M needs to pull data over the PCIe lanes which is a much longer way and slower. The Intel GPU practically has full speed access to the system memory. You can do a lot with drivers here.

More VRAM just is of little to no use and limits how much RAM you can use for the OS. It cannot be dynamically adjusted at runtime thus it would be foolish to make it any bigger than reasonable.