Imac memory

digitalfailure

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I have a 3.06ghz iMac here that has 2x2gb sticks of ram installed in 2 of the 4 slots.

I'm thinking of adding another 8gb to help it along, if I get the 2x4 sticks can I leave the other 2 sticks in place and run the machine with 12gb, or do the sticks all need to be the same size?
 
The 2x2 are matched and the 2x4 will be matched. I'm more concerned about the sizes of the matched sticks iykwim
 
You'll be fine. I generally go on the principle that as long as the 2 rear banks are matched and the two front banks are matched then it's good. But realistically you can stick whatever you want wherever you want as long as the RAM speed is correct. You'll need to check this, but in your case I think the model you're talking about takes PC8500/1066 speed - I may be wrong hence the need to check.

Historically it was essential that RAM was matched for the computer to even start, more recently you could work with unmatched RAM but there would be a performance hit. These days I've seen no mention of mismatched RAM affecting performance, but it's generally good practice to match at least pairs.
 
8Gb of ram from crucial is just under 50 quid delivered, it's a small price to pay I think for the speed increases when working in CS5 with 1gb+ images, especially if firefox is sat there playing youtube music in the background :D
 
Slaphead said:
You'll be fine. I generally go on the principle that as long as the 2 rear banks are matched and the two front banks are matched then it's good. But realistically you can stick whatever you want wherever you want as long as the RAM speed is correct. You'll need to check this, but in your case I think the model you're talking about takes PC8500/1066 speed - I may be wrong hence the need to check.

Historically it was essential that RAM was matched for the computer to even start, more recently you could work with unmatched RAM but there would be a performance hit. These days I've seen no mention of mismatched RAM affecting performance, but it's generally good practice to match at least pairs.

Hate to be pedantic but some systems slots 1 and 3 are paired etc ;)

Corsair still don't recommend mixing sticks, remember while the speed can be the same the cas, latency and voltages can differ :)
 
Crucial have a nifty little download which will double check your RAM and then list the upgrade.

Just about to order RAM for my imac now:thumbs:
 
Critical memory is good. I have the exact same match as you

I've used Crucial in all my Pc's laptops and macs for years and never had a problem with their kit.

Your running 2x4 and 2x2 in an icore mac ?
 
Hate to be pedantic but some systems slots 1 and 3 are paired etc ;)

Corsair still don't recommend mixing sticks, remember while the speed can be the same the cas, latency and voltages can differ :)

You may well be right, but I think we'd need to go back quite a way to find a mac with that requirement, however there are still Apple machines that require certain matching to perform at their best

The Mac Pros for instance pretty much aways require matched pairs, but the pairing system changes slightly depending on the model, and the latest version has it's own particular voodoo when it comes to installing ram (it's theoretically faster with just 3 DIMMS in each bank of 4 slots, rather than all 4 slots being full), but the machines will generally run regardless of how the RAM is installed, albeit it with a warning message, and just not as efficiently.

You're right about the cas, latency and voltages, but I've seen enough iMacs with 4 different DIMMs all different sizes from various manufacturers running quite happily (end user installed I hasten to add) to realise that this probably isn't that much of a problem these days, but good practice would always dictate matching the RAM, and I would never recommend mixing sizes and manufacturers within a matched bank.
 
Ordered 8gb at lunchtime, :thumbs:

Thanks for all the comments
 
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