Is new iMac able to run 4gb of Ram??

[RiDE]

The BTO options show that you can order the machine w/ 3GB of RAM (1 x 2GB and 1 x 1GB).... Would it be possible (I know a lot of $$$) to go 4GB (2 x 2GB)?

 

[trpnmonkey41]

# 17-inch model with 2.0GHz processor, 20-inch and 24-inch models

* 1GB (2x512MB) of PC2-5300 (667MHz) DDR2 memory
* Two SODIMM slots support up to 3GB

Not sure why it would support 3gb and not 4gb but that is what apples techspecs say

If you are doing the sort of work that requires 4gb ram you probably should be looking at the Mac Pro and not an iMac though

 

[RiDE]

Right... I am NOT doing the sort of work that requires 4GB... I just thought it odd that apple would list the ability to go 3GB(2+1) and not (4GB(2+2)... Maybe they didn't want to list the Option costing an additional $1300 for a base unit that is $1499.

 

[Billy-B0b]

Or maybe because the iMac wont benefit from having 4GB of Ram making people move towards the mac pro. I think Apple have been very clever on making the specs for there new iMacs and Mac Pro machines

 

[EDIT-XTREEM]

i have heard that you can put 4 gbs in but it will only reconize 3...

 

[Aptmunich]

Yup.

According to a memo we received, the chipset apple uses is intel's 945. It can theoretically address 4GB, but only when its running at 557Mhz. Apple is running the chipset at 633Mhz, which causes the system to only be able to address 3GB.

But when running 1+2GB modules you lose the benefit of the dual-channel performance architecture.

 

[RiDE]

Yup.

According to a memo we received, the chipset apple uses is intel's 945. It can theoretically address 4GB, but only when its running at 557Mhz. Apple is running the chipset at 633Mhz, which causes the system to only be able to address 3GB.

But when running 1+2GB modules you lose the benefit of the dual-channel performance architecture.

Thanks for the info... So what would be the VERY best RAM configuration? 1+1 with utilizing Dual Channel Performance, or 1+2 withOUT Dual Channel performance???

I also found this apple link regarding this question:
This link seems to say that the 1+2 would "maximize" RAM, but does that mean it would perform better than the 1+1?

http://docs.info.apple.com/article.html?artnum=304284


TIA

 

[AlexN]

Also, I assume that it will run in dual-channel mode when there is two RAM modules in (2 x 1GB), correct?

 

[Aptmunich]

Yup, although the actual speed benefits of dual channel mode are somewhat unclear. I've heard of reports of 10% performance increase and of 50% better.

 

[EDIT-XTREEM]

from apples site: Note: If you do install a 2 GB SO-DIMM in both the bottom and top memory slots of the computer, the About This Mac window and Apple System Profiler will both show that you have 4 GB of SDRAM installed. However, Activity Monitor and other similar applications will reveal that only 3 GB of SDRAM has been addressed for use by the computer.

 

[CanadaRAM]

Which one is faster depends on what you are doing. Matched RAM I would guess at 6 - 8% improvement. (35%-50% is the territory of XBench synthetic benchmarks, which are only one step removed from outright fiction)

But here's the thing... as soon as your programs and data consume more than the 2 Gb of physical RAM and you start paging to the hard drive, the memory performance plummets. At that point, having the extra 1 Gb RAM in the 3 Gb config is way faster. Until you open a bunch more programs and break the 3 Gb barrier that is, and then it all goes in a handbasket anyway.

So if you are doing digital audio, video, big Photoshop, etc. with programs and data sets that can use more than 2 Gb, then the unmatched 3 Gb is your ticket.

Thanks
Trevor
CanadaRAM.com