Did I install my Memory in the best slots?

[Vantage Point]

I have a 27" iMac and recently picked up the latest model MacBook. I also picked up a 4Gb (2x2) RAM. I placed the 4Gb in the MacBook and decided to place that 2GB from the MB in my iMac to boost it to 6GB.

Here is my question, did I place the RAM in the best slots, assuming there is such a thing as best slots. I remember from the old day of PC that there was a strict order for placement else I may not get the most out of the additional RAM. It does register as 6GB when I click on 'About This Mac'. Below is a diagram and screen shot to show exactly what I did.

 

[peteullo]

I have a 27" iMac and recently picked up the latest model MacBook. I also picked up a 4Gb (2x2) RAM. I placed the 4Gb in the MacBook and decided to place that 2GB from the MB in my iMac to boost it to 6GB.

Here is my question, did I place the RAM in the best slots, assuming there is such a thing as best slots. I remember from the old day of PC that there was a strict order for placement else I may not get the most out of the additional RAM. It does register as 6GB when I click on 'About This Mac'. Below is a diagram and screen shot to show exactly what I did.

You should be fine.

 

[Hellhammer]

To enable dual-channeling, the 2GBs have to be in BANK 0 and 1GBs in BANK 1, I think

 

[Vantage Point]

To enable dual-channeling, the 2GBs have to be in BANK 0 and 1GBs in BANK 1, I think

Thanks, I think. This seems to be a confusing topic since it is hard to pin down. Before I installed it I called up Apple and they indicated that the position was not important but when I tried to get a firm answer by restating the question a few different ways I could not get a clear statement out of the tech - who even contradicted herself once.

Also, I had done some performance tests for Photoshop and plugins earlier and after I installed the new RAM I redid the tests. The results were not conclusive in that some tests ran slightly slower and some slightly faster - on the exact same files with the exact same things open and closed. Of course since it is not using 64-bit Photoshop these tests with 6GB ram have little meaning as the current version is only 32 bits and thus will not use more than 3GB ram except to help out as a scratch disk. This is when I decided to post the question.

I tried to confirm is matching the size modules for dual channeling is better to insert in the same DIMM or same Bank but all I came up with was a older reference on Wikopedia which implied the same Banks but a thread on the Apple site had someone stating they should be in the DIMM slots. There are also some things written that there is no difference in position at all and other things written that state if it is wrong then it will register but not perform or may under perform relative to the largest 2 ram chips.

I would hate to have added the extra ram and not have it do anything because I did it wrong. Soon Photoshop CS% will be out and be able to use more RAM. Although I am relatively happy now, I can always use the extra RAM.

 

[Hellhammer]

Thanks, I think. This seems to be a confusing topic since it is hard to pin down. Before I installed it I called up Apple and they indicated that the position was not important but when I tried to get a firm answer by restating the question a few different ways I could not get a clear statement out of the tech - who even contradicted herself once.

Also, I had done some performance tests for Photoshop and plugins earlier and after I installed the new RAM I redid the tests. The results were not conclusive in that some tests ran slightly slower and some slightly faster - on the exact same files with the exact same things open and closed. Of course since it is not using 64-bit Photoshop these tests with 6GB ram have little meaning as the current version is only 32 bits and thus will not use more than 3GB ram except to help out as a scratch disk. This is when I decided to post the question.

I tried to confirm is matching the size modules for dual channeling is better to insert in the same DIMM or same Bank but all I came up with was a older reference on Wikopedia which implied the same Banks but a thread on the Apple site had someone stating they should be in the DIMM slots. There are also some things written that there is no difference in position at all and other things written that state if it is wrong then it will register but not perform or may under perform relative to the largest 2 ram chips.

I would hate to have added the extra ram and not have it do anything because I did it wrong. Soon Photoshop CS% will be out and be able to use more RAM. Although I am relatively happy now, I can always use the extra RAM.

If the 6GB is utilized, you're fine. Dual-channeling is like ~5% boost anyway, so almost nothing. CS5 should make use of that extra 3GB so it's definitely worth it.

 

[Vantage Point]

Thanks. I would like to eventually figure out if I am getting that extra 5% but I agree it is not worth going crazy over a potential bump that I probably would not notice. I am still in awe of how fast both a Macbook (even with only 2GB ram) and the iMac is relative to my nearly 4 year old slow poke XP PC.