iBook, lid-closed mode, full VRAM to external possible (hack)?

lorkp

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Original poster
Apr 27, 2005
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For now, I have decided on a 12" PB. But I would prefer to get an iBook because it was just released and it won't hurt as much when updated powerbooks will likely be released at the Paris Expo. But here's why I'm not going to get iBook—unless someone can confirm something for me.

I'm going to be using whatever laptop I get with an external monitor (a Dell 2005FPW to be precise). I think spliting 32MB is a bad idea with this large monitor unless there is some hack that will let the iBook run in lid-closed mode and give full memory to the external display. Does anyone know if this is possible?
 

zakatov

macrumors 6502a
Mar 8, 2005
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South Florida
iBook natively does mirroring, which does NOT split the 32mb VRAM. Only with the video spanning hack does the vram get split. It's also not a good idea to force the iBook to run with the lid closed.

EDIT:
You should not close the display lid of an iBook (Dual USB) computer while using an external keyboard and monitor.
Apple Support Page
 

lorkp

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Original poster
Apr 27, 2005
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zakatov said:
iBook natively does mirroring, which does NOT split the 32mb VRAM. Only with the video spanning hack does the vram get split. It's also not a good idea to force the iBook to run with the lid closed.

EDIT:

Apple Support Page
Thanks for the reply. I realize that the iBook dispates heat through it's keyboard, but I would take another look at iBook if there was a way for it to run an external display with all of its VRAM like a powerbook would do when it's display is closed. I realize this would take some sort of hack. Is it available?
 

Rod Rod

macrumors 68020
Sep 21, 2003
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Las Vegas, NV
The PowerBook also dissipates heat through its keyboard, but I suppose lid closed operation is supported because the metal enclosure all around helps conduct the heat. Maybe running one of those USB fans into the iBook's vent holes on the left side would help during lid closed operation?

Anyway, I'd be interested in lid-closed operation of a current iBook with the full VRAM going to the external monitor also. However, since I occasionally connect my 12" PowerBook to a 23" cinema display, I sort of need the DVI.
 

ITASOR

macrumors 601
Mar 20, 2005
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I'm pretty sure in clamshell mode is uses all 32MB for the other display. In system profiler it still says 32MB VRAM, so that's where I get this conclusion from.

I've never really tried this, but there was a hack somewhere I think where using a magnet you can fake the computer into thinking it is closed.

On the Athlon laptop in my signature, Function + F1 turns off the internal LCD and leaves on the external monitor attached. This is really nice because then the full 64MB is on the external. I think this would have been a good update to the PowerBooks. Then it can stay open and heat can come out of wherever it wants.
 

Hattig

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Jan 3, 2003
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London, UK
Are you sure the VRAM gets split? I know with two displays you'll have a lot more contention for it, but I'm sure it isn't split 50:50, it is just two displays in the same shared VRAM pool.

Of course, at 1024x768, a double buffered image is 6MB. A 1680x1050 display is 13.5MB. One full screen window would add another 7MB. So you could realistically have both displays operating, with the iBook for IM and dashboard, etc, and the large one for work, but you'd only have enough video memory to realistically run one full screen application and a few part-screen applications at a time before you hit AGP texturing slowdown.
 

ITASOR

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Mar 20, 2005
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Hattig said:
Are you sure the VRAM gets split? I know with two displays you'll have a lot more contention for it, but I'm sure it isn't split 50:50, it is just two displays in the same shared VRAM pool.

Of course, at 1024x768, a double buffered image is 6MB. A 1680x1050 display is 13.5MB. One full screen window would add another 7MB. So you could realistically have both displays operating, with the iBook for IM and dashboard, etc, and the large one for work, but you'd only have enough video memory to realistically run one full screen application and a few part-screen applications at a time before you hit AGP texturing slowdown.
It splits it 50:50.

This is one thing I don't like about the hack. I think when people are doing something that risky to their computers, they would want to know what they heck it does and how it actually works. The site doesn't really even explain it, just tells what it is that it does.
 

Hattig

macrumors 65816
Jan 3, 2003
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London, UK
ITASOR said:
It splits it 50:50.

This is one thing I don't like about the hack. I think when people are doing something that risky to their computers, they would want to know what they heck it does and how it actually works. The site doesn't really even explain it, just tells what it is that it does.
That's an odd way for it to work. Is it the only way to get around the method that Apple disabled it with? Oh well, it does give you two displays, one for IM and email and occasional stuff, and one for working on. Also, you can save memory by changing the display from "Millions" of colours to "Thousands", but can you do that on a per-display basis? Shame there isn't an option to split the memory 8:24 instead of 16:16 really.

Edit: Or keep the mirroring, but change it so that the resolution is the external monitor's resolution, and set the iBook's display to show a portion of the large display (a window upon the screen). I know that this is possible on Windows.

Also, why did you get 768MB for your new iBook? Surely that's 512MB built-in and a 256MB SODIMM? Wouldn't a 512MB or 1GB SODIMM be more optimal?
 

lorkp

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Original poster
Apr 27, 2005
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I'm the OP, heh. I don't think I made myself clear. I'd only want to run with the lid closed because that's how Powerbooks give full VRAM to the external display. This is also the reason why I leaning toward the Powerbook—16MB of VRAM does not cut it for the 1680x1050 display I want to use. If there was a way turn off the display and keep the lid open, as ITASOR mentioned with his PC laptop, I would purchase and then be all up in the iBook...to speak frankly. I'm asking if there is some way to run an external display with 32MB VRAM.

Thanks for the help!