How much video memory do you need in OSX? (AnandTech)

[VirtualRain]

I wasn't aware that OSX utilized the GPU in this way.

The contents of each window and the windows themselves are drawn by the GPU and stored in video memory. Previous versions of OS X either drew windows in system memory and then composited all of them in video memory, or did everything in system memory and just outputted the final scene to the video card. Ever since OS X 10.4, the entire drawing and display process happens on the GPU and in video memory. Ars Technica’s John Siracusa has an excellent explanation of the whole process.

Conclusions...

While it would take 70 normal windows to max out the 512MB of video memory on a GeForce GT 120 at 2560 x 1600, it would take less than nine 12MP images open in Photoshop to do the same. And once again, you don’t get that memory back when you close your images - only after you exit Photoshop. Most other windows in OS X will give you your GPU memory back as soon as you close the window.

If you find yourself doing a lot of work in Photoshop, you’ll want to either limit the number of images you have open at once or disable OpenGL acceleration. And by all means, quit the app once you’re done editing. Of course you could always move to a graphics card with more memory...

Link: http://www.anandtech.com/video/showdoc.aspx?i=3602

 

[Pressure]

That puts things into perspective as I usually work with 22MP RAW pictures.

Although I rarely work on more than 3 at the same time.

Read it earlier though and wasn't surprised.

I doubt the majority of people ever hit that 512MB framebuffer (with 70 open windows).

 

[Animalk]

Wow thanks for sharing this article with us. Very interesting and Anandtech has been very on the ball concerning OS X and Apple hardware lately might I add. They made an excellent article on the 2009 Mac Pro that I shared in the "Are 2009 Mac Pro's overpriced thread" which gives an excellent explanation of how the 8 core 2.26Ghz overclocks itself when only using 1 or 2 cores to improve performance. I believe its called Turbo Mode.

 

[Tesselator]

Mmmm, this is a bit misleading. It's true what they're saying but when GPU memory is full it swaps out to system memory and the delay is minute.

I edit 12 and 24 MP images a lot. On the 7300GT PS tells me my limit is 7 but allows many more. I can open 30 and they are all the same fast speed after a single 1/10 of a second hiccup.

How much is enough? As with all memory you can never have enough! But any of the cards from the 7300GT on up will edit photos at virtually the same speed no matter how many windows you have open assuming you don't also run out of system memory.

 

[Dr.Pants]

[Anandtech] made an excellent article on the 2009 Mac Pro...

That same article, if I can recall corrctly, had praise for MDP.

Although it IS nice to justify a 1GB VRAM card, if one is completly out of memory

 

[Topper]

Although it IS nice to justify a 1GB VRAM card, if one is completly out of memory

Actually, I wouldn't mind having a 2GB VRAM video card.
How about a HD 5870 x2 for Macs? Yeah, I know, dream on.
X-Plane can probably use a 2GB VRAM card.
With texture compression turned off, X-Plane uses as much as 940MB of VRAM.
That's with a Gigabyte 9800GTX+ video card and the monitor set to 1600x1200.
My monitor's resolution is 2560x1600. So....

 

[MacVidCards]

I found this interesting so I did some tests.

I tried opening a variety of 15MP images on different cards.

On a 256 Meg card the warning popped up @ 4 images
On a 512 Meg Card the warning came @ 9 images
On a 1 Gig card the warning came @ 16 images
On the 2 Gig GTX285 the warning still came @ 16 images


So, either there are flaws with CS-4 using more than a 1 Gig card or something.

Does anyone know what app he was using to track amount of VRAM used?

 

[TK2K]

That puts things into perspective as I usually work with 22MP RAW pictures.

Although I rarely work on more than 3 at the same time.

Read it earlier though and wasn't surprised.

I doubt the majority of people ever hit that 512MB framebuffer (with 70 open windows).

well if you're running multipule monitors it could happen..
it's a very interesting article

 

[Loa]

Hello,

Interesting article, but once again I'm wondering about real-world performance (outside of games).

Is there any detectable real-world performance decrease once we saturate our GPU's memory?

Thanks

Loa