2012 cMBP - NVIDIA GeForce GT 650M with 512MB or 1 GB RAM?

Discussion in 'MacBook Pro' started by ConscienceNL, Jun 19, 2012.

  1. ConscienceNL macrumors newbie


    Jun 19, 2012
    I wonder how important the difference is between 512MB and 1GB RAM for the NVIDIA GeForce GT 650M. I've heard people say that a somewhat older graphics card with 1 GB RAM isn't better than a current graphics card with 512MB RAM.

    I'm not going to use the MBP for gaming and video editing, but I do use it for Photoshop. What does this VRAM actually do, and by thinking of the future (I plan on using the MBP for 3 years, with the 1680 x 1050 resolution and 8 GB of RAM), will 512 MB be enough?
  2. Rizzm macrumors 6502a

    Feb 5, 2012
    For some games 512 will be enough. The VRAM does exactly what regular RAM does. I'm not a computer expert, but I think I can explain it at least somewhat.

    Instructions are loaded into RAM to be read by the CPU. The GPU has faster access to VRAM (since it's built on the card), and so instructions (from games, etc.) can be read more quickly. When VRAM is full then regular RAM has to be used.

    The biggest need for more VRAM comes from the resolution you're playing at. Playing at 1680 x 1050 should be great for most games, but there are still some that need over 512MB.
  3. ConscienceNL thread starter macrumors newbie


    Jun 19, 2012

    So, how much would VRAM impact other things like Photoshop, OS X itself, video's from YouTube? As I said, I'm not using it for gaming so that doesn't matter to me.
  4. Rizzm macrumors 6502a

    Feb 5, 2012
    Silly of me to just assume you were going to be gaming with it. :D

    Can't comment from experience but I'd say you'll be more than okay. Pretty sure that only 3d graphics intensive applications like modern games and 3d design would require the better card.
  5. leenak macrumors 68020

    Mar 10, 2011
    For what you are using it for, you don't even need a graphics card. You might want to look at a MB Air instead.
  6. dusk007 macrumors 68040


    Dec 5, 2009
    Every open window wants some VRAM even if not visible. So do VM.
    If you have too many things open and too little VRAM animations will star become sluggish and choppy. More VRAM helps.
    It is completely unimportant for Youtube or video. That is priorities and always gets the little VRAM it needs.
  7. ConscienceNL thread starter macrumors newbie


    Jun 19, 2012
    Allright. Forgive me for my questions, but since I plan on using it for quite some years and the VRAM can't be upgraded, I want to make sure I'm choosing the right amount of VRAM.

    I usually have like 10-15 tabs open and some (light) programs running in the background. Does this impact much of the available VRAM?

    And if the maximum amount of VRAM is used, won't the normal RAM be used instead so it doesn't matter that much?

    At the moment I use a windows laptop with 2GB VRAM, so I don't really know what a lower VRAM does.
  8. Fishcake21, Aug 20, 2012
    Last edited: Aug 20, 2012

    Fishcake21 macrumors member

    Feb 25, 2011
    In your case, Vram isn't really an issue.

    512mb is more than efficient to do anything OSX wise, even opening a bunch of windows, as they only take just from 8-10MB

    You might notice some sluggish animation when using an external monitor and having anything over 1080p. Otherwise it should be fine. Higher pixel counts benefits with more vram. Otherwise if you are using your LCD screen on the macbook pro, no worries.

    The only time when one needs that much vram is pratically gaming, though OSX games should run efficientely, including normal games running in windows, I can't say much for high end games like Skyrim or Rage that uses high quality textures. The game will pause/break once in a while just to load new ones into the video memory from main ram to framebuffer. versus having it instantly. Its not annoying by any levels but you will notice the pauses. Nvidia does a great job with buffering more textures to memory than ATI, ATI cards you really do need more vram. Games like Skyrim will benefit from extra Vram, even some options i believe are turned off unless you have 512MB or more vram. Otherwise general games doesn't really matter

    http://www.youtube.com/watch?v=7i0ayaPNajI This is a prime example when you are running a game that uses high quality textures and low on vram. It runs smooth framerate wise, but you can see textures popping in and out because of low vram, though there are fixes to help make it smoother.
    http://www.youtube.com/watch?v=mYuB7wtqneU this is the same game running with 512mb of vram, it runs fine, but if you look very carefully there are texture popups.
    though this is with games that requires high end cards because they have high quality textures. Most other normal games will run fine.

    But then again, if you are really gaming, why get a macbook pro? :> Don't think about using parallel desktop too if you are going to do minor gaming, it will chew faster on vmra

    As for productive applications, the only thing i can think of is when doing 3d modeling, you do need the vram as having less makes it studdering and it can be annoying in a workflow.
  9. sofianito macrumors 65816


    Jan 14, 2011
    Here is my take on:

    VRAM stands for Video RAM (Ramdom Access Memory). It is a dedicated RAM used only by discrete GPU (Nvidia GT 650M) to load gpu instructions and to perform operations on different graphics maintained on that memory.

    The integrated GPU (Intel HD4000) has no dedicated VRAM. Hence, it will operate on laptop main memory.

    I am not expert, but I think the HD4k will have faster access to main RAM (clocked at 1600Mhz) than the GT 650M to its DDR3\GDDR5 VRAM (maxed by GPU clock at 900Mhz).

    By default, Mac operating system, based on some thresholds (would be great if someone provide more details on it), will switch dynamically from HD4k to GT 650M if needed. Also, I am not sure if the maximum memory addressed by HD4k is capped by the operating system...

    Unless your play heavy 3D games or do heavy 3D rendering, I believe the 512MB VRAM of the GT 650M would be enough.

    Apple has been very flexible by allowing average consumers to configure the CPU, RAM, and disk of the rMBP base model, but has been very short by not allowing pro users to choose between 512MB and 1GB of VRAM size for the cMBP base model...
  10. leman macrumors G3

    Oct 14, 2008
    For your purposes, 512 VRAM is more then enough. A framebuffer (whole screen) takes less then 10Mb for a 1680x1050 display. OS X does use VRAM for normal (2D) window rendering, but even having many windows is very unlikely to see any VRAM-related problems.

    Textures are often mirrored in both VRAM and RAM (there are exceptions to this, but its a complicated topic). Textures and other data are
    also streamed from the system RAM to the VRAM as required. So if VRAM becomes limited, the GPU will simply grab the required data from the system RAM. This is only a performance consideration for games though, the normal desktop usage will not saturate the GPU to system RAM connection.


    This is correct. Because the Intel Integrated Graphics is basically part of the CPU, it will get 'first-hand' access to the system RAM. Also, driver is able to do much magic here. For example, with a dedicated GPU the data has to be copied from the system RAM to VRAM. With the IGP, the driver can eliminate the copy and let the IGP access the client data directly.

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