Why would someone get 3GB of Ram?

levitynyc

macrumors 65816
Original poster
Aug 19, 2006
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Based on the configuration wouldn't there be mispaired RAM issues?

I am talking about the new iMacs
 

Xenesis

macrumors regular
Sep 3, 2006
197
0
Australia
The bigger question is why you wouldn't put that $750 USD towards a Mac Pro.

That's...rather sickening price. And didn't the mispaired RAM affect performance so minimally that it didn't matter anyhow?
 

MacBoobsPro

macrumors 603
Jan 10, 2006
5,115
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levitynyc said:
Based on the configuration wouldn't there be mispaired RAM issues?
I doubt having mispaired RAM is going to make a noticeable difference. Sure it will technically run slower but it will hardly be noticeable as RAM is accessed virtually instantly anyway no matter what config.
 

~Shard~

macrumors P6
Jun 4, 2003
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Paired RAM is preferred and ideal, but not having it will not negatively impact your system's performance. It may not run as well as with paired RAM, but it definitely won't result in poor performance.
 

weeag

macrumors regular
Dec 27, 2005
132
0
levitynyc said:
Based on the configuration wouldn't there be mispaired RAM issues?
I've got 3GB, two 512's and two 1MB - no mispairings.
 

~Shard~

macrumors P6
Jun 4, 2003
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Does anyone know why the limit is 3 GB though? Is it a firmware/motherboard limitation? What happens if you stick two 2 GB sticks in the new iMac?
 

weeag

macrumors regular
Dec 27, 2005
132
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Xenesis said:
The iMac only has two ram slots though, so you need a 2GB and a 1GB.
Ok, didn't realize the discussion was for iMac's. And do the new boards require paired Ram like the old ones?
 

Sayer

macrumors 6502a
Jan 4, 2002
981
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Austin, TX
Paired RAM is required in the Mac Pro, but all other Macs currently do not require it at all, and really won't benefit all that much from it when used.

Basically all paired memory does is create a double-wide memory path that can improve memory bandwidth. However, memory bandwidth is only a part of the overall performance of any computer system. This is especially true when the hard disk(s) have spun down, as anyone with multiple HDDs knows all too well.

The real bottleneck today is hard disk speed, which is why Microsoft is *requiring* Flash RAM + HDD instead of only HDD to use Windows Vista effectively.
 

Caitlyn

macrumors 6502a
Jun 30, 2005
842
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I think 3GB is a fair deal with the iMac. If Apple had added a 4GB option, that could have been stepping on the toes of the Mac Pro...which it is already, kind of. :rolleyes:
 

MacBoobsPro

macrumors 603
Jan 10, 2006
5,115
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weeag said:
I've got 3GB, two 512's and two 1MB - no mispairings.
Doesnt the MP access RAM in 4s instead of G5 pairs? I think thats what is meant with 'mispairing' even though it is grammatically incorekt. :)
 

savar

macrumors 68000
Jun 6, 2003
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District of Columbia
stuartluff said:
I doubt having mispaired RAM is going to make a noticeable difference. Sure it will technically run slower but it will hardly be noticeable as RAM is accessed virtually instantly anyway no matter what config.
The difference is around 5% from what I hear. Far too little to be noticed by an end user. Just enough to get pick up by a decent benchmark.
 

Sun Baked

macrumors G5
May 19, 2002
14,874
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savar said:
The difference is around 5% from what I hear. Far too little to be noticed by an end user. Just enough to get pick up by a decent benchmark.
Yes, double the speed of RAM isn't as big a speed boost as people would expect -- unless the machine used RAM as VRAM.

Otherwise, people will notice the speed of not having enough RAM -- because there is a bigger difference between the speed of ram (5300mbps) and the hard drive (50-75mbps)
 

Lollypop

macrumors 6502a
Sep 13, 2004
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Johannesburg, South Africa
With the discrete graphics on the imac there isnt really anything that requires so much bandwitdth, all of it goes to the CPU. The extra ram could be good for future versions of OS X and bit apps such as final cut and Aperture.

Im still interested on how exactly Apple gets to 3gigs... one laptop slot, and one normal desktop slot (laptops top out at 1gig and desktop slots top out at 2gig)?
 

mrgreen4242

macrumors 601
Feb 10, 2004
4,355
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AJ Muni said:
Apple sells ram? People actually BUY RAM from apple? :rolleyes: :p
The 2gb option on the new iMacs aren't horrible... $175. Would cost $300 - whatever you could eBay the old RAM for if you got it from Crucial. So, not completely unfair at all.
 

admanimal

macrumors 68040
Apr 22, 2005
3,531
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~Shard~ said:
Does anyone know why the limit is 3 GB though? Is it a firmware/motherboard limitation? What happens if you stick two 2 GB sticks in the new iMac?
There is some architectural issue that prevents the system from being able to address memory beyond 3GB. So if you install 4GB, you will still effectively only have 3GB.