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512MB vram Vs. 256MB vram

M

MichaelThomas

macrumors member
Original poster
Feb 3, 2007
98
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I do alot of final cut/after effects work and Im starting to do alot of work with 3D recently. I read somewere that 512MB doesnt make any difference.

Anyone want to explain how this works as I'm totally unfamiliar with GPUs and there memory!

Thanks alot :)
 
It's not an option. If you get the 2.4GHz MBP, you get 256MB of VRAM; if you buy the 2.53/2.8GHz MBP, you get 512MB of VRAM.
 
alphaod said:
It's not an option. If you get the 2.4GHz MBP, you get 256MB of VRAM; if you buy the 2.53/2.8GHz MBP, you get 512MB of VRAM.
Click to expand...

I know its not an option. What Im getting at is would i see a noticeable difference with the 512 over the 256?

If so then OBVIOUSLY I would have to jump over to the 2.53/2.8 rather than the 2.4

Thanks
 
Say you run your internal display and an 30" external, the extra VRAM will allow you display more graphical elements while still maintaining performance. Also for an application like Photoshop CS4 where the GPU is utilized, the additional VRAM will be useful.
 
Zero. None. Nada. Zilch. Zip. A whopping 0% increase, maximizing the speed by 0x.

The 128 bit interface limits the card to utilizing only 256MB of VRAM. You won't even notice a 1% bump.

EDIT: To explain it further, I'll pull a post straight from the notebook review forums:

"1.Is a GeForce 8600M-GT 256MB DDR2 better than a GeForce 8600M-GT 512MB DDR2?

This is a very common train of thought – more video memory must mean better performance. This is not true – the video card itself matters much more than the memory it has.
In this case, both cards have the same performance. The 8600M-GT DOES NOT HAVE ENOUGH POWER to use more than 256MB of memory. It has a limited 128-bit memory bus. Only cards with a 256-bit bus or greater are going to be able to use more than 256MB of memory. It is not worth spending any extra money on a mid-range card like the 8600M-GT with more memory. There is no performance gain to justify the price.
Why can't it use more memory effectively? Here's a primitive example. An office worker can use a maximum of three computers at a time. If he is given an additional three computers, is he any more productive? No, because he can only use three of them to begin with. The extra three do nothing."

Tale note that the 9600 has a 128 bit interface like the 8600.
 
alphaod said:
Say you run your internal display and an 30" external, the extra VRAM will allow you display more graphical elements while still maintaining performance. Also for an application like Photoshop CS4 where the GPU is utilized, the additional VRAM will be useful.
Click to expand...

Cheers for that. Makes much more sense now.
I have a 23" ACD and will be upgrading to CS4 soon so this will clearly help out alot. Is there limitation to how much VRAM can be used compared to normal RAM?
 
Coldwater said:
Zero. None. Nada. Zilch. Zip. A whopping 0% increase, maximizing the speed by 0x.

The 128 bit interface limits the card to utilizing only 256MB of VRAM. You won't even notice a 1% bump.
Click to expand...

So the 512MB will only utilise 256MB REGARDLESS of what you through at it?
Will this change in snow leopard?
 
I thought that the 9600 was more optimized and could take in the 512MB? Or was I wrong?and you mean maximised by 1x, not 0x ;)
 
MichaelThomas said:
So the 512MB will only utilise 256MB REGARDLESS of what you through at it?
Will this change in snow leopard?
Click to expand...

Correct. See my edited example above. It just doesn't have the power to access that memory and no, Snow Leopard will make no difference.

Notice that the 9600M GT is much weaker then the 9600GT used in desktops, the main reason being the desktop version has a 256 bit interface capable of using 1GB of VRAM. The 9600M GT is more comparable to the desktop 9500.

http://www.notebookcheck.net/NVIDIA-GeForce-9600M-GT.9449.0.html

"Compared to desktop graphics cards, the 9600M GT is similar to the GeForce 9500GT (which also descends from the G96 core). The desktop CPU 9600 GT has a 256 bit memory bus and is therefore much faster."

raymondu999 said:
I thought that the 9600 was more optimized and could take in the 512MB? Or was I wrong?and you mean maximised by 1x, not 0x
Click to expand...

Optimization makes no difference. Oh, you and your semantics. :D
 
Coldwater, Cheers for all that! I really appreciate it.

So why is there a 512MB option then? Just for marketing hype?
 
Coldwater said:
Here's a primitive example. An office worker can use a maximum of three computers at a time. If he is given an additional three computers, is he any more productive? No, because he can only use three of them to begin with. The extra three do nothing."
Click to expand...

Heres my example, you have 256 cups of water that need to be filled. You have 1 pitcher(A) that can hold 256 cups of water, and 1 pitcher(B) that can hold 512 cups of water. Now, which one can fill 1024 cups of water faster?

or whatevers...
 
MichaelThomas said:
Coldwater, Cheers for all that! I really appreciate it.

So why is there a 512MB option then? Just for marketing hype?
Click to expand...

Bingo. Bigger numbers look better. And no problem, I was nearly trapped the same way on the old MBPs, until I decided to hold off for these new ones; during that time I learned the differences. I still went with the top model for the processor bump (the ram being thrown in and the cheap hard drive helped as well). :D
 
pimentoLoaf said:
Not according to an ArsTechnica review -- it has a 256-bit bus.

So yes... you will notice a difference.

(BTW, I was writing this before all the discussion above this and below Coldwater's post)
Click to expand...

In all fairness that is the desktop part...but given that this is a totally new mobile chip design from nVidia I would hope that it would be a 256-bit bus as well. I'd be curious to find a real answer to this, as the added memory for gaming is one of the larger reasons I am getting the top end 15" model.
 
That arstechnica review is about desktop model. What you read there does NOT apply to the 9600M. 9600M is the one used in laptops.
 
pimentoLoaf said:
But it also says it can have a maximum RAM of 1024mb. I suppose all that extra RAM is just for show, too?
Click to expand...

Yep. Bigger numbers are there to look better, especially in this case because that 1GB would be of GDDR2 RAM, so it would be even slower and more useless then 512MB of GDDR3 RAM.
 
Guys, you are completely, totally wrong. You can make some arguments about whether the extra video RAM is useful for certain applications, but it definitely isn't just sitting on the card PHYSICALLY DISCONNECTED from the rest of the system, present for only marketing reasons.

The width of the bus affects the memory _bandwidth_, which will have an effect on performance, but it's not like it can't use all the memory.
 
Coldwater said:
Correct. See my edited example above. It just doesn't have the power to access that memory and no, Snow Leopard will make no difference.
Click to expand...

This is a fruitful discussion...

If I understand you properly, then the 512MB is entirely useless for present and future MBPs. I'm no expert, but that seems to be a very bold statement. First, Snow Leopard won't be released until summer of 2009, so saying that it will not utilize that extra memory seems a bit hasty. Second, if that extra memory is indeed completely useless, then how come no one is crying/screaming about it? Judging by the way people reacted to the glossy display, you'd think that they would have some strong words concerning needless/overpriced hardware. :rolleyes:

In my uninformed opinion, there must be some logical explanation for the extra memory. Any ideas of what it could be? It can't simply be a marketing ploy - even Apple needs a prima facie justification for a hardware upgrade.
 
If your going to be driving a larger external display your better off having the 512mb.
 
avalys said:
Guys, you are completely, totally wrong. You can make some arguments about whether the extra video RAM is useful for certain applications, but it definitely isn't just sitting on the card PHYSICALLY DISCONNECTED from the rest of the system, present for only marketing reasons.

The width of the bus affects the memory _bandwidth_, which will have an effect on performance, but it's not like it can't use all the memory.
Click to expand...

In pratice, you wouldn't really see a performance increase though, as the can't transfer the data fast enough even with a larger frame buffer in place due to the reduced bus width. It would take very high resolution to make any difference (I'll concede, you'll see a bit) BUT that brings me to my 2nd point:

In all honesty, it won't matter in the end. Computing is a game of bottlenecks. Adding the RAM will shift it to a different spot, but in order to really utilize that RAM you'd have to have some pretty powerful application, which in turn will place the bottleneck back on the CPU or RAM, defeating the purpose. A more powerful card would see a much larger gain, while Apple wants you to believe the same for this card. Don't fall for it.

The bottom line: If you are spending the extra purely for the VRAM bump you are wasting your money.

EDIT:
nope7308 said:
Second, if that extra memory is indeed completely useless, then how come no one is crying/screaming about it? Judging by the way people reacted to the glossy display, you'd think that they would have some strong words concerning needless/overpriced hardware. :rolleyes:
Click to expand...

It was the same for the last revision. Perhaps people are getting used to it? :D

I'll be the first to admit I don't know everything on the subject (sorry if I made it seem like I was some sort of video card expert :D) but I can honestly tell you I believe you will see little to no gain, and that Snow Leopard will make little difference, though I could be wrong as my knowledge of it is incomplete. (That seems to be more reliant on clock speeds and stream processors and the like.)
 
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