05-16-2007, 03:21 PM

I was going to see if this money saving technique will be worth the effort.

If I buy the 20" iMac with the basic 1 GB of RAM (2x512) for $1570

but then buy 3 GB of RAM from Crucial.com for $360, and install I can save around $300 by not using Appple's $675 3GB upgrade. Only having two extra 512 MB RAM chips lying around.

Any advice from those have tried this before?

05-16-2007, 03:28 PM

I'm doing the exact same thing (Except I'm only going for 2gb of ram). RAM arrived yesterday and the iMac should be here by friday (I hope)

05-16-2007, 03:31 PM

I was reading on another post and they said that if you have (1) 2GB chip and (1) 1GB chip, the dual something won't be in effect, resulting in a slower machine.

Is that true?

05-16-2007, 03:39 PM

The memory is Dual Channel memory that works best when paired. But the logic board in the iMac can only handle 3gb so its impossible to pair it. 2 1gb sticks will operate in dual channel mode and will give a performance increase, but 3gb will allow you to do more work.

Basically the performance loss by not using matched pairs is outweighed by you having 3 gb.

05-16-2007, 04:05 PM

A lot of members go with the method you're describing, and everybody is happy with their purchase (I know I am )

Like trpnmonkey said, dual channel doesn't really offer much in tangible performance benefits. It's only in synthetic benchmarks where you see a boost, which don't translate to real world use

05-19-2007, 03:19 PM

Originally Posted by trpnmonkey41

The memory is Dual Channel memory that works best when paired. But the logic board in the iMac can only handle 3gb so its impossible to pair it. 2 1gb sticks will operate in dual channel mode and will give a performance increase, but 3gb will allow you to do more work.

Basically the performance loss by not using matched pairs is outweighed by you having 3 gb.

According to crucial website, the iMac does not support dual-channel memory so you do not need to install identical pairs for optimal performance. The mini, on the other hand, does support dual-channel memory, as with the macbook.

05-19-2007, 07:30 PM

Crucial's website is wrong, the chipset in iMacs most definitely support dual channel RAM. In fact, they use the same chipset that are in the Macbook/Macbook Pro, so it would be odd for dual channel not to work.

In fact, dual channel has been a feature in all motherboards for several years now

05-19-2007, 10:07 PM

Originally Posted by Kash

Crucial's website is wrong, the chipset in iMacs most definitely support dual channel RAM. In fact, they use the same chipset that are in the Macbook/Macbook Pro, so it would be odd for dual channel not to work.

In fact, dual channel has been a feature in all motherboards for several years now

I got the following off other forums:

"The iMac G5 does not do Dual Channel access, it does a junior version called 128-bit access. To achieve this, Apple says that the RAM modules must be the same size, speed and 'composition' - but they din't define that very well."

"The people at Crucial tell me that since the new(iSight) iMac has one chip soldered to the motherboard, it's not a dual channel. As a result, the matching of memory sizes will not come into play on the new one."

Can anybody confirm this?

05-20-2007, 02:11 PM

Checking more of the iMac lines on crucial.com, the older iMac G5 does support dual-channel (or rather 128-bit access), but this ended with the iMac G5 with DDR2, as well as the iMac G5 iSight. All of the Intel iMac lines don't support it, according to the website, but it would be nice if someone could confirm it.