Why only 2 gig of RAM on the new iMacs

[dogbone]

Why do the new (or the old for that matter) iMacs only have a capability of 2 gig of RAM?

My first G4 500 had 1.5G and I thought that was pretty good then.

Now all these years later my new eMac can take 2Gig. Which makes sense after 5 years.

But it doesn't make sense to me that the new iMac can't take any more ram than my emac. I know it's better RAM but the programs I use rely more on RAM than processor speed and I'd definitely want my next computer to be able to do 4Gig at least. Seeing as the new powermacs can take 16 gig, 4gig is still very much a consumer computer level.

 

[belvdr]

I disagree. When you look at the iMac being marketed at the consumer level, I cannot see the average consumer needing more than 2GB over the life of the system.

Referring to users who surf the web, type documents, and other light duty chores, I see no reason for 4GB of RAM.

 

[mchendricks]

RAM Prices

How many consumers are going to spend about $300 US for a 2GB memory module? And that is for some of the cheaper RAM I found. Crucial 2GB DDR 3200 RAM was over $500 a piece. Most people that will spend $1000 for RAM will opt for (need) a PowerMac, not an imac.

Mike

 

[dblissmn]

2GB is the normal limit on a 32 bit chip. The G5 is a 64 bit chip, so the limit in practice is dictated by the number of slots. In this case, one. So a G5 iMac can go the 512MB soldered to the main board plus the 2GB the single slot can take, or in other words 2.5GB, while the Yonah implementation of the iMac is limited to 2GB, arranged in the form of two slots that can each take a gigabyte.

 

[Chaszmyr]

2GB is the normal limit on a 32 bit chip.

Not true, the limit on a 32 bit chip is 4gb.

 

[CanadaRAM]

Higher RAM capacity means more RAM sockets --- which means larger machines and more expensive components. You can do this in a Pro level tower, but not in a consumer model laptoop (or an iMac, which is a laptop motherboard, essentially, strapped to the back of a monitor.)

Possibly -- and without developers notes from Apple, this is just speculation -- the machines will be able to go to 4 Gb when (if) 2 Gb DDR-2 667 SODIMMs are released. However this will be pricey.

I just quoted on some 4 Gb DIMM server memory -- a set of four sticks is over $10,000

 

[fuzzie]

Not true, the limit on a 32 bit chip is 4gb.

Well, the single-process limit on a 32-bit chip is normally 2gb, as it is under Darwin. And most people wanting excessive amounts of memory would want it to throw memory at a single program requiring a heap of memory, I'd expect..

Obviously with extensions like PAE you can have much much more RAM in a 32-bit machine than 4gb, but single processes can't use all that, and I doubt Yonah supports it.

 

[dogbone]

The reason I ask is that I was looking at getting an imac when the rev B's come out and I'm mainly interested in more ram because of Zbrush which needs a lot of RAM.

I only use Zbrush for my own entertainment purposes rather than for work and it likes to push around massive polygon objects in real time. I was working with a 6million poly model this morning and it can bearly do anything with 1.3gig of ram made available for Zbrush. It's writing to disk constantly.

Although ZB is used by professional studios it is still very much a consumer piece of software, and if I can't put a lot more ram in, an iMac is pretty well useless to me as my rammed up eMac handles all my photoshop stuff with ease, and there's no way I could splash out on a powermac and monitor just to use Zbrush.

 

[CanadaRAM]

Although ZB is used by professional studios it is still very much a consumer piece of software, and if I can't put a lot more ram in, an iMac is pretty well useless to me as my rammed up eMac handles all my photoshop stuff with ease, and there's no way I could splash out on a powermac and monitor just to use Zbrush.

Looks like you're for a used PowerMac G5 dual or quad then.

 

[mopppish]

Hey, on the same topic, what would it take for my rev b imac G5 to take 2X2G chips in the future for a total of 4 gig? Is this just a firmware update that Apple would have to produce, or is there more involved?

 

[CanadaRAM]

Hey, on the same topic, what would it take for my rev b imac G5 to take 2X2G chips in the future for a total of 4 gig? Is this just a firmware update that Apple would have to produce, or is there more involved?

Motherboard redesign?

It all depends on the memory controller chip in the machine, whether it could recognize 1024 MBit devices or not. A 2 Gb module would have to be built with super-high density 1 Gbit chips, because there is only room in there for a 16-chip module.

If the memory controller can't address the high density chips, it's game over.