8 GB ram upgrade for Unibody 15"

Ok --- haven't seen this question yet, so I will ask it !

Now that the new Unibody 17" Macbook Pro has been announced and it has the ability to upgrade to 8GB of Ram, why is the Ram limit for the 15" Unibody apparently limited to 6GB ?

Just curious if this is indeed a firmware problem or ?

 

I am sure it will be possible, but right now 8GB is going to run near $1000, so I wouldn't worry about it for awhile.

 

I agree and I'm not looking to "Upgrade" either. 4GB is fine for my needs but I would like to get a definitive answer as to whether the new 17" is configured differently (hardware) or if this is indeed and firmware change that will be provided for the 15" models. When Ram prices go down, I would certainly entertain the option.

 

I thought I've heard that the RAM limit on all new Macbooks wasn't really 4GB. Not that it matters right now with prices being so ridiculous.

 

The current limit for all macbook pros (atleast from Santa Rosa) is 6GB(15&17 inches).

After that, OSX doesnt really like it. So in theory, most of the macbook pros should be able to handle 8gb, but itll be a while until they do (if they do at all)

So yea, if you need more ram, 6GB is the limit atm. Hopefully later it will be 8gb if they work out whats wrong.

 

Well, I understand that recently most reports are that 6GB is the limit for the newest 15" MBP's, but if you read my first post the new 17" MBP state that they will operate on 8GB of Ram and it is an option with Apple to purchase.

So again this is the big question. If the newest 17" MBP just released can operate on 8GB, why won't the 15" unibody with seemingly the same spec's as the newest 17" ??????

 

the fact that they are now making a laptop that can use 8gb of ram, means that they either tweaked a different build of osx that lets laptops use 8gb of ram. maybe it's 10.5.7 and it will be released along side with the 17".

Either that, or they changed the hardware, or chipset, or something, and now the new ones can use 8gb of ram, and the old ones cant. Maybe a firmware update will all that will be needed, but noone knows at the moment.

 

Sulkorp

Sounds logical --- Yours being an answer that I can at least understand.

Even though it seems that the answer might not be available at this time, I'm sure after at least broaching the issue someone will have an answer sooner or later


I appreciate all the answers from everyone

 

I can't see how OS X has anything to do with the 15" models not supporting 8GB of RAM. The 10.5.6 available from software update is exactly the same build whether you are updating a 15" MacBook Pro or a Mac Pro yet the Mac Pro has no problems supporting 16GB of RAM. 10.4 Tiger supported the full 16GB in the Mac Pro just as 10.3 Panther supported 8GB in the Power Mac G5.

The 15" MBP not running stably with 8GB is most likely a hardware limitation rather than a software one. Personally, I think the problem is in the chipset itself, seeing that Apple actually launched the Unibodies before nVidia even officially announced the 9400M chipset themself. The advantage of getting first dibs on hardware is that you get the limelight, but you are acting as guinea pigs for everyone else. Perhaps 8GB support just didn't work in the early versions or they didn't have enough time to officially certify them for 8GB.

A firmware update may correct things but it's highly unlikely. Apple generally doesn't add new features through a firmware update and if they did they would probably have to charge for it like the 802.11n enabler for the 2nd-gen MBP or the iPod Touch updates. It's also unlikely, because if they do release a firmware update, it's assumed that they are guaranteeing stability under 8GB of RAM, which is a liability they probably don't want to bother with for products that they already shipped.

 

But Apple IS guaranteeing the 8GB of Ram. That guarantee just happens to be in the new 17" model so I don't see why this would be an issue with the new 15" from Apple.

Plus I haven't ever heard of apple providing modified chip sets this early out of the gate with new models. Certainly doesn't look cost effective to do so from apple !!!!!

This certainly is getting more confusing here ?

 

It may be a firmware difference as well. Most likely it will support 8gb though.

 

I'd imagine that the 15-inch MacBook Pro, at some point, will allow for 8 GB of RAM through a firmware update.

 

The point is that you are assuming the chipset in the 17" MBP and the 15" MBP is exactly the same. nVidia actually has a new revision of the 9400M chipset starting to be available this month. (This new revision is suppose to be more mature and run cooler). Perhaps the 17" MBP incorporates this new revision and Apple supports 8GB on this revision. It may not be possible to support 8GB on the older 9400M revision or may not be worthwhile to putting development effort on testing and then supporting it.

And Apple has used modified/custom chips and chipsets many times. The processor and chipset in the first MacBook Air were custom made for Apple and were actually a 65nm test of the Small Form Factor design Intel officially introduced with the 45nm Penryn. The processors and chipsets in the current iMacs are actually all customs designs and are actually overclocked Santa Rosa platforms instead of the the Montevina platform that came after. Apple regularly uses early production runs of Xeon processors in the Mac Pro with a higher 150W TDP, before they are standardized into the more standard 130W TDP. When Apple gets products out before the rest of the industry, it's almost always special production runs in order to not upset other OEMs.

 

my guess is you won't see a big difference from 4GB to 8GB.

But the Extra 4GB will just sit there eating up battery life.

DDR3 uses 1.5 volts

 

If this in any way true --- I will stand corrected !

I just could not conceive of a change in chip set so early in the production run. It's still the same platform so that was my theory. Anything is possible though.

 

lt_commander data here is a link to a pretty lengthy discussion about 8gb and 6gb of ram in macbook pros.

From the little that I've read, it seems that osx and the hardware does see the 8gb of ram, its just that osx doesnt use it properly once you get above 6gb.

It seemed like it was an osx issue, rather then hardware, though it could be a strange hardware thing. I'm not sure though about windows, I didnt read the thread enough to see if they tried it in windows to see if it handles it differently.

But yea, considering that mac pros use upwards of 8gb of ram, I wondered why the laptops couldnt. it seemed like it was an issue with osx and the laptops, rather then the hardware itself. So thats why i'd think they would maybe have to release some kind of patch for leopard to make it work in the laptops?

But if we're going by apple specs, we shouldnt expect more then 4gb of ram to work. Thats what they claimed, and thats what we get. Although people have said, that like right now, the cost of 8gb of ram was so expensive, they didnt bother listing it in the spec (intel i think in the chipset? something along those lines), but later on in life as ram becomes cheaper it does become a reality.

But yea, thats all i gotta say. Theres probably more then enough info in that thread for someone to read and come to conclusions. and on the last page theres a little speculation on why the new ones work with 8gb and if the old ones could too.

 

Erm.. that depends if you run out of the 4GB of memory no?
If you do you'll see a big difference. You'll also hear your hard drives a lot more also.

Regards,
Simon

 

The chipset and OS X supports 8 GB of RAM in the 13.3'' and 15.4'' unibody MacBooks, but it's most likely limited to 6 GB by Apple in the firmware. The reason? Most likely a product differentiation thing, to make the new 17" stand out.

 

I'm sure they'll release a 8GB supporting firmware along with Snow Leopard this year.

That's the time I'm going to upgrade to 6GB or even 8GB anyways. It's still very expensive to upgrade at the moment.

 

Thanks to Sulkorp, lt Commander and all for the replies.

That's what I like about these forums. With enough "facts" and a little "speculation" this will be answered. While I am like most others, I don't want (or need) to upgrade Ram at this juncture but it sure would be nice to have the option at a later and more cost effective date. This is one of the reasons that I upgraded to the new aluminum body Macbook Pro along with the new hardware in preparation for Snow Leopard and it's advantages.