What does the GPU do?

bep207

macrumors 6502
Original poster
Jul 20, 2006
259
0
What does the GPU do exactly? more specifically in regards to Aperture. I am running a 128 Radeon X1600 on my MBP with a 20" cinema displayed spanned for the large images and the MBP screen for the library.

Before you ask, I only have 512 ram in the MBP right now as I am trying to wait until prices come down on DDR2 RAM.

I know the RAM is a huge limiting factor. But will I ever notice the GPU slowing me down?
 

charpi

macrumors regular
Sep 30, 2006
203
10
im not so sure but this is what i think....

if ur video card has dedicated RAM, say 128mb, then it will draw memory from there and the RAM would not affect it that all, RAM will, however, still affect normal RAM based procedures like multitasking...

however if u have integrated graphics like GMA 950 then RAM matters alot!!

this is wad i think, hope i could help ;)
 

bep207

macrumors 6502
Original poster
Jul 20, 2006
259
0
yeah it has 128mb of RAM,

is there any application or way of checking how much of that RAM is available, used, and so forth at any given time

much like activity monitor does for regular RAM
 

Lollypop

macrumors 6502a
Sep 13, 2004
829
0
Johannesburg, South Africa
GPU stands for graphics processor... in the olden days the GPU only put the 2D image the OS gave it on the screen, and when games were played it took intructions from the game,and then "drew" a set of shapes on the screen, these shapes formed the graphics of your game, the reason the CPU doesnt do this is becuase its not designed to do it, and a dedicated processor can do it much much better and much much faster. The GPU memory is used to store the instructions for the GPU and the results of the processed intructions, and sometimes bitmap images as well.

With later versions of the Mac OS (I think 10.2 maybe 10.3) the GPU no longer does 2D graphics anymore, the OS sends 3D instructions to the GPU to draw the GUI, this allowed for a overall increase in speed as the CPU was now left with less to do, with Tiger (10.4) Apple created a freamwork for developers called Core image that allowed them to write programs that could use the more graphics optimized features of the GPU, in effect have faster graphics effects, a well as have lower CPU usage. I think Aperature uses Core Image to do most if not all of its graphic/image manipulations, so the manipulations run very fast because the GPU does some work and the CPU as well, the GPU memory is used to store your manipulated images...

Very long worded but I couldnt think of a better way to describe what a GPU does in relation to Aperature... hope it explains it!
 

hope

macrumors newbie
Apr 9, 2006
26
0
So uh... How's the GPU in the Macbooks compared to the ones in the latest Powerbooks and new Macbook Pros. Would you see any differences in performance other than in gaming??? I know the Macbook has integrated graphics card but if your running 2gb of ram, should it run good?
 

Lollypop

macrumors 6502a
Sep 13, 2004
829
0
Johannesburg, South Africa
hope said:
So uh... How's the GPU in the Macbooks compared to the ones in the latest Powerbooks and new Macbook Pros. Would you see any differences in performance other than in gaming??? I know the Macbook has integrated graphics card but if your running 2gb of ram, should it run good?

Im not 100% sure, but besides gaming you will only notice the integrated graphics when you use applications that are heavy reliant on Core Image, ie Aperature, the ripple effect of Dashboard, maybe a few other applications, but right now its mostly pro apps that use core image a lot, and those people have money for a better graphics card, so end consumers wont really see a huge difference on anything besides games.
 

pengu

macrumors 6502a
Mar 20, 2005
576
0
Diddily Daddily...
Lollypop said:
Im not 100% sure, but besides gaming you will only notice the integrated graphics when you use applications that are heavy reliant on Core Image, ie Aperature, the ripple effect of Dashboard, maybe a few other applications, but right now its mostly pro apps that use core image a lot, and those people have money for a better graphics card, so end consumers wont really see a huge difference on anything besides games.
Not really. As you yourself stated Dashboard uses CoreImage, as does iMovie.

Bottom line: CoreImage isnt an essential system component, it's designed to fall back to use the CPU and provide an intermediate result if the GPU isnt powerful enough, but dont expect wonders out of anything that has lots of eye-candy.
 

hope

macrumors newbie
Apr 9, 2006
26
0
Would you see a differnce in the quality of videos played? If it falls back to the CPU, isn't it powerful enough to makeup for it enough? I know a dedicated video card is worlds better but... How much of a difference will it make from the Powerbook's 9700 w/ 128mb vram? I know the MBP have what, a X1600 so that is a big jump. Should I see an improvement from the PB though?
 

gauchogolfer

macrumors 603
Jan 28, 2005
5,555
5
American Riviera
bep207 said:
What does the GPU do exactly? more specifically in regards to Aperture. I am running a 128 Radeon X1600 on my MBP with a 20" cinema displayed spanned for the large images and the MBP screen for the library.

I know the RAM is a huge limiting factor. But will I ever notice the GPU slowing me down?
Per Aperture, I think that even people with Quad G5s and upgraded video cards have reported some issues with Aperture in full-screen mode when doing edits and image rotation. So, I think that you might notice the GPU slowing you down with Aperture, but at least you won't be alone. :)
 

hope

macrumors newbie
Apr 9, 2006
26
0
So essentially, only with heavy visually intenstive apps (i.e. Aperature), I would see some loss in graphics and or slower speeds?
 

Lollypop

macrumors 6502a
Sep 13, 2004
829
0
Johannesburg, South Africa
hope said:
Would you see a differnce in the quality of videos played? If it falls back to the CPU, isn't it powerful enough to makeup for it enough? I know a dedicated video card is worlds better but... How much of a difference will it make from the Powerbook's 9700 w/ 128mb vram? I know the MBP have what, a X1600 so that is a big jump. Should I see an improvement from the PB though?

Video quality wouldnt differ at all, providing your CPU is strong enough to actually decode the source video.

generik said:
The GPU pumps folding@home work units
Has the beta of folding at home that uses the GPU been released yet? I read something about this on anandtech, but it said the beta still wasnt available?

pengu said:
Not really.
Im not following?? End consumers, meaning no-pro users wont really have many applications that will really leverage core Image, so they wont notice its absense?
 

dmw007

macrumors G4
May 26, 2005
10,635
0
Working for MI-6
Lollypop said:
GPU stands for graphics processor... in the olden days the GPU only put the 2D image the OS gave it on the screen, and when games were played it took intructions from the game,and then "drew" a set of shapes on the screen, these shapes formed the graphics of your game, the reason the CPU doesnt do this is becuase its not designed to do it, and a dedicated processor can do it much much better and much much faster. The GPU memory is used to store the instructions for the GPU and the results of the processed intructions, and sometimes bitmap images as well.

With later versions of the Mac OS (I think 10.2 maybe 10.3) the GPU no longer does 2D graphics anymore, the OS sends 3D instructions to the GPU to draw the GUI, this allowed for a overall increase in speed as the CPU was now left with less to do, with Tiger (10.4) Apple created a freamwork for developers called Core image that allowed them to write programs that could use the more graphics optimized features of the GPU, in effect have faster graphics effects, a well as have lower CPU usage. I think Aperature uses Core Image to do most if not all of its graphic/image manipulations, so the manipulations run very fast because the GPU does some work and the CPU as well, the GPU memory is used to store your manipulated images...

Very long worded but I couldnt think of a better way to describe what a GPU does in relation to Aperature... hope it explains it!

Nice explanation Lollypop. :)


hope said:
So uh... How's the GPU in the Macbooks compared to the ones in the latest Powerbooks and new Macbook Pros. Would you see any differences in performance other than in gaming??? I know the Macbook has integrated graphics card but if your running 2gb of ram, should it run good?
No, the integrated video card in the MacBook keeps it from playing games well. More RAM would likely help (overall system peformance more than anything), but it will not let you really enjoy playing any modern, graphic intensive games such as Doom 3 or Quake 4. :)
 

Warbrain

macrumors 603
Jun 28, 2004
5,699
287
Chicago, IL
dmw007 said:
Nice explanation Lollypop. :)




No, the integrated video card in the MacBook keeps it from playing games well. More RAM would likely help (overall system peformance more than anything), but it will not let you really enjoy playing any modern, graphic intensive games such as Doom 3 or Quake 4. :)
I don't know if more RAM would help with the integrated graphics as they are already wired into a set amount of the RAM that comes with the computer. It might make things a bit snappier, but it won't help the graphics at all.
 

Xeem

macrumors 6502a
Feb 2, 2005
902
9
Minnesota
hope said:
Would you see a differnce in the quality of videos played? If it falls back to the CPU, isn't it powerful enough to makeup for it enough? I know a dedicated video card is worlds better but... How much of a difference will it make from the Powerbook's 9700 w/ 128mb vram? I know the MBP have what, a X1600 so that is a big jump. Should I see an improvement from the PB though?
The PB's Radeon 9700 is still substantially better than the Macbook's GMA950 in most areas. However, the GMA950 is very specialized for video playback, and can actually decode play back HDTV resolutions that some more powerful cards cannot. My iBook's 32 MB Radeon 9550, for example, will still benchmark better than the Macbook's GMA950 more often than not in most games and other apps, but the Macbook can play back 1080p whereas my iBook cannot (not sure about the PB though)
 

bep207

macrumors 6502
Original poster
Jul 20, 2006
259
0
i am using Hardware Monitor on my MBP

using Aperture on the MBP and on a 20"ACD for full screen images

I am seeing that the Free RAM is consistently under 5mb.
The GPU is never using more that 30%
The CPU is never more than 30%

I think its obvious where the bottleneck is.

Granted I am running Aperture on the stock 512mb RAM, but I have a 1gig stick arriving tomorrow, i'll let you know what happens with 1.5gb RAM
 

Lollypop

macrumors 6502a
Sep 13, 2004
829
0
Johannesburg, South Africa
bep207 said:
i am using Hardware Monitor on my MBP

using Aperture on the MBP and on a 20"ACD for full screen images

I am seeing that the Free RAM is consistently under 5mb.
The GPU is never using more that 30%
The CPU is never more than 30%

I think its obvious where the bottleneck is.

Granted I am running Aperture on the stock 512mb RAM, but I have a 1gig stick arriving tomorrow, i'll let you know what happens with 1.5gb RAM
I wasnt aware that Harware Monitor actually gives the usage of the GPU as well! Are you sure its not the second CPU? Also the memory free reading on a mac isnt that acurate, sometimes after using my machine for a while the free memory goes to about the same as yours, but even after i quit all my apps the figure doesnt drop much.
 

bep207

macrumors 6502
Original poster
Jul 20, 2006
259
0
yep Hardware Monitor, the application, not to be confused with Activity Monitor does give you a reading for GPU load

Now that I have installed the extra gig of RAM
now have 1.5gb
Aperture is VERY snappy and quick

The GPU never goes above 20% and the RAM never drops below 300mb Free

I cant wait to see what will happen when I eventually upgrade to 2gb and get them paired