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drift
Nov 24, 2004, 04:46 AM
Hello,

The installed memmory can't be replaced in new imacs....right?

So, ordinarily I would buy a 1g from crucial add have 1g256m in total.

But someone told me, that running on RAM chips of different sizes has some speed implocations in itself. They said i'dbe better off getting 256m pre-installed on 1 chip aqnd adding 256 from crucial, ot if I wasn't gong to be generous to others this holiday season, get 1g pre-installed and 1g from crucial :)


point is... if chip sizes are not equal...does this have some speed/running consequences?

cluthz
Nov 24, 2004, 05:15 AM
Hello,

The installed memmory can't be replaced in new imacs....right?

So, ordinarily I would buy a 1g from crucial add have 1g256m in total.

But someone told me, that running on RAM chips of different sizes has some speed implocations in itself. They said i'dbe better off getting 256m pre-installed on 1 chip aqnd adding 256 from crucial, ot if I wasn't gong to be generous to others this holiday season, get 1g pre-installed and 1g from crucial :)


point is... if chip sizes are not equal...does this have some speed/running consequences?

No there are two slots in the new iMac (the G5) so you can easily remove the 256mb stick if you wan't. Don't get 1GB pre-installed, it's too expensive. Get 2x 1024MB from crucial and then you'll have 2.0GB in your iMac :D

drift
Nov 24, 2004, 06:14 AM
OK - that was what theytold me at apple store!..I'm going to phone agian now.....

drift
Nov 24, 2004, 06:26 AM
Great...I just phoned up again and got a more switched on salesperson.

Installed chip is deinietely removable :) :) :)

2 crucial g's ahhhh)

Chip NoVaMac
Nov 24, 2004, 07:26 AM
2 crucial g's ahhhh)

You also might want to look at OWC as another option for the memory.

rosalindavenue
Nov 24, 2004, 07:42 AM
In the "lamp" iMac, wasn't one of the ram sticks soldered in?

cluthz
Nov 24, 2004, 11:29 AM
In the "lamp" iMac, wasn't one of the ram sticks soldered in?

No, not soldered, but pretty difficult to reach.
You will void the warraty if you change it yourself.
A service center could do it, you could also do it yourself if you've got a bit experience with computer hardware.

micvog
Nov 24, 2004, 11:38 AM
But someone told me, that running on RAM chips of different sizes has some speed implocations in itself...

If you have paired memory (i.e. two identical memory modules - not just two modules of the same size), the memory bus is 128-bit; otherwise it is 64-bit (even if you have just one module). What this means, and whether it has a significant performance impact, I don't know. IIRC, one test showed that a 256MB+1GB configuration was slower than a 512MB+512MB configuration.

maya
Nov 24, 2004, 11:54 AM
I believe the G5 likes symmetric ram as in if there are 2 slots per chip it like ram of the same rating for example:

slot 1: 256
slot 2: 256

= GOOD

slot 1: 256
slot 2: 1024

= BAD (as in slow downs).

Anyhow this is what I gather from the PMG5 it could or could not be the same for the iMac G5.

drift
Nov 24, 2004, 07:27 PM
If you have paired memory (i.e. two identical memory modules - not just two modules of the same size), the memory bus is 128-bit; otherwise it is 64-bit (even if you have just one module). What this means, and whether it has a significant performance impact, I don't know. IIRC, one test showed that a 256MB+1GB configuration was slower than a 512MB+512MB configuration.

Thanks for the info :)

CanadaRAM
Nov 25, 2004, 12:04 AM
I believe the G5 likes symmetric ram as in if there are 2 slots per chip it like ram of the same rating for example:
slot 1: 256
slot 2: 256
= GOOD

slot 1: 256
slot 2: 1024
= BAD (as in slow downs).

Anyhow this is what I gather from the PMG5 it could or could not be the same for the iMac G5.

I don't believe so: In an iMac G5 the extra 768 Mb of available RAM in your Bad example would probably outweigh the performance difference of 64 vs 128 bit access in your 512 Mb Good example.

I would characterize the iMac G5 question as:
Total 1 GB:
A
Slot 1: 1Gb
Slot 2: 0
Normal speed (64 bit access)

B
Slot 1: 512
Slot 2: 512
Slightly faster than normal because of 128 bit access

If you are referring to the PowerMac G5s, the point is moot -- you have to install pairs in the tower G5s anyway.

Thanks
Trevor
CanadaRAM.com

bellis1
Nov 25, 2004, 12:44 AM
Search through the threads and you should find more on this topic. My take was that the performance difference would be so extremely slight. Although I personally just decided on two 512 for my imac since I will not be ever needing more than a gig (at least I hope). Neither of the memory sticks is soldered in. I bought crucial and they work and were the cheapest I could find anywhere (at newegg, backordered at outpost). Anyone want my old 256 that apple installed. I'll practically give it away.