RAM Question

[Tom]

So next week, we are buying a 27" iMac.
Pretty sure on the refurb i5.
$1529
i5 2.66GHz
4GIG RAM
1TB HD

Since it is a refurb, all upgrades have to be done after market.

The first thing to come to mind is RAM. There are four RAM slots, and Apple sends it with 2x2GIG. Is there a reason I shouldn't get 2x4GIG RAM and stick it in the two open spots to have 12 GIG? Then eventually replace the 2x2GIG with 2x4GIG?

[dmcantrell]

IMO, more RAM is never a bad thing.

[TxLerman]

The central issue with going beyond 4 GB of ram is the operating system's ability to use any ram above 4 GB. What operating system are you going to use and can it take advantage of the extra RAM?

[srwatters]

If you're looking for the absolute best performance, it's often suggested that you use all the same size DIMMs. I know that on the Mac Pro, there is an optimal way to use the 8 slots on the two memory risers. I'm not that familiar with the iMac, but a little research on the Apple forums should find the best pairings. On the Mac Pro if you use 4 DIMMs that are of the exact same size and speed, the system will be able to burst wider bus access when filling the on CPU caches. That of course results in faster execution of programs etc.

BTW, if it's a new iMac, it will come with 64 bit Snow Leopard, so David's question about RAM size above 4GB isn't relevant. I currently have 16GB in my Mac Pro running the same OS and it often can use it all!

And on a side note, I strongly recommend OWC (Other World Computing http://www.macsales.com) and Memory to Go (http://www.memorytogo.com) for your Macintosh memory needs. All 5 of my Macintosh machines have memory from one of these two companies.

[JohnT]

I've enjoyed http://crucial.com in the past, but I haven't done a price comparison with the sites Scott suggested.

[Tom]

I've just heard that it is best to replace all your memory at once and have the same memory. But I figure a 2G+2G+4G+4G > 4G+4G of RAM. Didn't know if I would see dimishing returns from it.

[zebulus]

Originally Posted by Thomas Campbell

I've just heard that it is best to replace all your memory at once and have the same memory. But I figure a 2G+2G+4G+4G > 4G+4G of RAM. Didn't know if I would see dimishing returns from it.

As long as your memory is the same speed, it shouldnt matter.

It in theory is better to have your modules all the same size, but I think as long as they are the same speed, you shoudlnt have any issues.

Your motherboard dosent care what the name brand is though.

[Rson]

Originally Posted by Thomas Campbell

I've just heard that it is best to replace all your memory at once and have the same memory. But I figure a 2G+2G+4G+4G > 4G+4G of RAM. Didn't know if I would see dimishing returns from it.

That is fine, make sure the sizes are paired.

There are color coded slots....pair up the memory.

I like Crucial and Mushkin, never had a problem. Makesure you get the correct stick type.

[srwatters]

I looked on both the Apple forums and OWC and discovered for the iMac, installing two matching SO-DIMM modules at a time is best. But this isn't always the case. The Mac Pro uses FB-DIMMs (8 slots) and with the Xeon memory architecture, installing four matching modules at a time allows for 256bit wide memory operations. Just a FYI...

[Tom]

So in summary:
Buying 2x4GIG of RAM and installing it in the 2 open spots is cool while leaving the 2x2GIG of RAM in the other two spots. My computer will speed up.

[srwatters]

In short. Yes. More RAM is good. More RAM installed in pairs of SO-DIMMs in your new iMac is best.

[Mask]

Get more RAM.
I upgraded to HP 6304f w/ 8400 CPU - like I5 and 8 MB RAM
in prep for CS5 and process of my Phase One 645 w 60 MB back.
For what its worth the new system is 4.5 times faster
than my old Pentium 4 system doing heavy disk IO.
It's not Apple to Oranges {PC} ... You need RAM for MFDSLR.
For Canon FFDSLR I would still recomend it.

[Rson]

Originally Posted by Thomas Campbell

So in summary:
Buying 2x4GIG of RAM and installing it in the 2 open spots is cool while leaving the 2x2GIG of RAM in the other two spots. My computer will speed up.

Yes, mind the color coded pairs. Might be blue and black. Match the color to the sticks.