Late 2008 unibody MacBook Pro + 6GB RAM + Snow Leopard = Kernel Panic

I apologize for the incorrect information provided by our customer service rep. The 2008 Unibodies have plenty of uniqueness and while we are pleased to provide support to 6GB vs. the official 4GB Apple states - we have discovered that some 4GB DDR3 SO-DIMM modules, while fine for use in 8GB capable models (going to 6 or 8GB) cause kernel panics in models where 6GB is an unsupported maximum. Back in 2008, before a series of firmware updates that Apple corrected widespread issues that affected even Apple's own 4GB (2GB x 2) Kits in the Unibody models, the use of a Samsung module kit was a last resort short of getting the MacBook itself replaced. Since the series of Firmware updates - issues with 2GB modules in these 'rev 1' Unibody models with 3GB and 4GB configurations are a well to the past.

A brief history of 6GB support...

In early 2009 OWC determined that you could actually upgrade MacBook and MacBook Pro Unibody models with up to 6GB of memory with recognized performance gains in those applications where more memory makes the difference.

We had started selling 8GB Kits for the new 17" Models and found that the same Factory Original Hynix 4GB DDR3 Module, same modules Apple was/is using for 8GB factory installed upgrades, would also support the 6GB config.

Then in May we encountered a wave of issues with the 6GB Macs and these 4GB modules. All the returns were specific to a batch of Hynix 4GB DDR3 - although no difference in p/n or identifier rev to explain. About the same time we also began offering Micron 4GB DDR3 SO-DIMMs and were able to qualify those for both 6GB and 8GB configs. Out of thousands of of the Micron factory original modules sold, we have now tracked a handful - from the same productions as modules with no issue - that did exhibit the issue when used in these 6GB limited unibody models.

Currently we proactively screen the 4GB DDR3 SO-DIMM modules that are provided as part of our 6GB Kit as well as sold singly where we list support for use in the 6GB limited models.

There is honestly no good explanation why certain 4GB DDR3 SO-DIMM modules will not operate reliable in those 6GB limited MacBook/MacBook Pro unibody models - while the same modules exhibit absolutely no issue once so ever when installed in any config (4GB, 4GB+2GB, 4GB+4GB) in a system that has 8GB capability.

The only explanation inferred is that the specification for the module has some variation that while a non-issue for systems that Apple has official support for their use within, is of a more critical element when it comes to the toleration in models that are not officially supported beyond 4GB.

these are premium, factory original modules - we build also build our own modules and will soon be building our own 4GB DDR3 SO - but I point out that this experience is with the same modules Apple has used in 8GB upgrades to note that it isn't something truly wrong of defective with the modules but more do do with the actual Unibody models that were Apple hasn't made more than 4GBs officially supported in.

As a side note - the current Mac mini DDR3 models do recognize 8GB when you install 4GB x 2, but only address and let you use 4GB max. That is a hard limit and hopefully the next gen of Mac mini removes this limit.

I hope this information helps. Feel free to email owc at macsales.com with questions/comments. Thank you.

- OWC Larry

I have a late 2008 MBP version 5,1 and ordered just the 1 x 4GB from OWC. I got it this morning and took out one of the Apple 1 x 2GB and replaced it with the 4GB. Put the lid back on and i've had no problems all day. I've been experimenting with both video cards as well as 32 & 64 bit kernals.
No probs.
Anyone think it has something to do with 10.6.1?

Sorry that it's not working for some......I

Thought I would share my experience as well.

I have a 5,1 MBP as well and have been dying to get over the 4gb limit since I have an SSD and don't want to put excessive wear on it. I bought an 8gb kit (hynix) earlier his year and was never able to get any of the 4GB sticks to work in any sort of combination: (2+4, 4+2, 4+0, 0+4, 4+4) under 10.5.6.
I was hoping SL 10.6.0 would resolve the issue and tried again after the upgrade with no luck: Kernel panic within a few minutes.
I just took another look at it today and learned about booting with the 64bit kernel. Amazingly it seems to work with 6GB... As I am typing...
It seems to me like it is a software issue with the 32bit kernel of SL in combination with the brand of RAM maybe?
I have not yet tried 8GB or using the 9400 GPU yet but I finally found a setting combination that seem to work.

Update,
I have now tried booting back in 32bit mode and it seem to be also stable. Strange...

The bottom line is, if you're exceeding Apple's documented hardware limits, don't expect it to work and don't expect it will continue to work if you somehow got it working before.

At least for OWC's product, they admit they've gone beyond what Apple supports, and so if you bought from them, they and only they are responsible for support.

Anyway, now to the solution of this problem until Apple gets it straight.

First, like every forum I've read on this, if you call Apple Tech Experts, go to a store and talk to sales and/or talk to their 'Geniuses' (I did all of the above before moving to 6GB), they'll tell you the machines 'officially' support 6GB. I more than triple verified and referred to what was published. Their response was that their internal technical publishing has since been updated to 6GB and there is no problem. Moreover, an Expert told me, you can probably get away with 8GB just fine, but we won't warranty or support it past 6GB. Support or warranty? Now why would 6GB be the limit if 4GB is the 'real' limit? They wouldn't - they'd support and warranty it only to 4GB if that was the case.

Before 10.6, 6GB worked just dandy. After the upgrade to 10.6, I saw the issue everyone else is seeing. Both on a 6GB machine and was on my wife's 4GB MBP - identical models, but mine I put 6GB in mine AFTER talking to 4-people at Apple (via the above avenues) about the supported amount as I didn't bother to think to check maximum at the time I bought these. Yes, saw it on her 4GB machine pre-10.6.1.

(I use nvram boot-args="-v" to have a verbose boot-up as well as kernel dumps - it's not as perty, but it is very useful in many ways beyond this.)

Now, after the upgrade to 10.6 on the 4GB machine, she was getting the panics with either Parallels or Fusion running for a while. I haven't put her on a 64-bit kernel yet (still). Once hers was updated to 10.6.1 the problem went away. When she was running into it, I didn't bother doing anything or looking deeply - I know the reality of initial releases. They can't possibly test the same as the masses can. So, I figured sit tight and it'll be addressed quickly. I did. It was. This is probably why you don't see many complaining with machines that have the max 4GB 'officially supported' hardware. Most people I know updated after 10.6.1 was released.

Now, onto my 6GB machine. I upgraded to 10.6 later and 10.6.1 was already available. The upgrade went no problem. 10.6.1 and all the various other upgrades: no problem. I promptly set it to boot 64-bit kernel (to avoid holding down 6+4 - I'd tell you how, but don't want this censored for being off topic 🙂. After working with the machine on/off for about a week (my primary OS is Linux on another laptop - I like OS X as well so it is my secondary for email/calendar/ms office/etc.), I started seeing the kp's. Then I became obsessed with determining the issue. I wrote some quick C progs and after a few days I found the issue. I'll say I found it on my machine since I have no way of determining how this will work on others. But, I suspect it will. I did tell my buddy about it who was having the same issue: solved his problem as well.

For reference on how well this has worked now for over a week: I have had multiple Parallels (5 beta) VMs running (Win7 64, WinXP, Ubuntu) simultaneously, a FF browser with usually 10 or more tabs open plus another window, Safari, Entourage, Mac Mail, Address Book, Live Mesh (oh yeah, I love it and use it), Time Machine backups, iTunes and usually a few terminal windows all running on different spaces. That's my typical running routine. Every since I've made the change I'm getting to: ZERO problems.

One thing I can say with beyond a high-level of confidence is that it's an issue with 10.6 (both Kernels and wasn't an issue in 10.5), which is why I periodically search to see if Apple has caught on yet. I spend enough time hacking Linux kernels and more years than I can remember on both Linux and BSD that I don't ever quite understand why flattening a machine and reinstalling is recommended - well, unless it's Windows or there are too many apps/variables to deal with. My point is, I'd rather get to the root cause, get it fixed and move on so that I never see it again; or if it comes up again, I can quickly solve (usually).

So, I encourage everyone to send the OSX automated log dumps to Apple as you receive them if you haven't been. Further, if you haven't, before making this change, grab at least another couple kernel panics and send the log dumps. This accomplishes two things: 1) allows Apple to see the issue on proper scale, 2) informs them what the problem is (easy to see if you study them - patterns built).

Finally, the fix, or workaround I should say, is easier than you might think: use the 9600M GPU (i.e., system preferences | Energy Saver | choose "Higher Performance" - logout, login, restart for good measure). My guess is the kernel will panic a few times on you before getting it straight.

Why? Because the 9400 uses shared memory and the amount adjusts with the amount of RAM. Wait, dude, are you saying you found that 10.6 isn't properly adjusting when you go over 4GB? In a way - I won't get too far into details on my supposition, but that's essentially it. See, it's not truly shared, but supposed to be reserved, BUT there is clearly a problem with a bounds overrun. The 9600 uses dedicated GDDR3 - no shared system memory - hence why no problem.

Further, this might give you an idea of why 10.6 introduced a pervasive flicker problem when using the 9400. Was it me, or just too psychedelic to work on for longer periods? I read about it some time ago in 10.5.n, but never experienced on 3 of my MBs and my MBP, my wife never did nor anyone I knew. However, it's on all of 10.6's now if you put it to sleep and raise the lid and get to work.

Why bothering mentioning this? This fixes that issue as well until it's addressed in 10.6.2 (that's the plan anyway). You may have tried some of the other workarounds or fixes (I warn you on these - could cause file system issues and will remove a lot of your defaults), but a hack when clearly, based on these two issues, 10.6 is not playing well with either the late 2008s or more current MBPs and their integrated GPU chipset (9400).

The config is NOT ideal as the machine runs hot, eats the battery and I don't need it (many don't even those who think they might - unless you do HEAVY graphics and/or gaming, the integrated chip works just fine).

So, is it really the amount of RAM? Not from where I sit. Brand? Nope. Pairing? Nah - that's just to ensure dual channel is available - if not, it goes single (though go with a paired set since single hits performance and heck if you need OWC to do that). Bad batch? You know how extremely rare this is? I have bought commodity memory since 286 (and prob. 8088, but don't recall) and built all my own computers a couple per year. Then worked in a DC assembling Proliants, installing IBMs/Dells/Rackables in the thousands - HDDs, MBs and RAID controllers were the #1 issue - never RAM. I can only recall over the last 20-years finding a bad memory module 2 or 3 times. Easy to detect on a PC, apparently not an Apple?

Now that I have this sorted, I might actually throw in 4GBx2 just to see what 8GB does. Oh yeah, pushing the memory limit and THEN, only then, can you lecture me 🙂 I suspect, that is where hardware limitations kick in.

< Edited by Host >

The technical specs on Apple's web site still list a maximum of 4 GB of RAM.

While not the absolute last word, they do try and keep them up to date:

http://support.apple.com/kb/SP499

Further, Crucial, a RAM vendor which would be happy to sell you as much RAM as possible and is very, very good about keeping specs up to date, also continues to list a maximum capacity of 4 GB:

http://www.crucial.com/store/listparts.aspx?model=MacBook%20Pro%202.8GHz%20Intel %20Core%202%20Duo%20%2815-inch%20DDR3%29%20Late-2008

So I'm a bit suspicious of the purported "updated specs" and OWC Larry's post on the topic above seems like it may be the most accurate on the topic.

I have the solution, but Apple keeps censoring my posts (not profanity, just frustration against Apple as well as their censorship) so I am not going to post on their forums.

Check others and I'll add to my blog.

Good grief - now that they censored it, I can't edit so enjoy.

This will probably be censored as well, but they kinda got the wrong guy on this one 🙂

Message was edited by: Dahde

Message was edited by: Dahde

Just comply with the Terms of Use.

All of the 2008 Unibody MacBook/MacBook Pros are all capable of 6GB of memory, and a special test is used certify the 4GB modules we provide for this non-Apple supported memory amount. Apple only officially supports up to 4GB in these models - and it would be difficult for them to officially support more than that because not all 4GB modules, even from the SAME production run (even talking Samsung, Hynix, and Micron original factory parts), operate reliably in these systems. Can't tell be looking at a module if will work or not - must be put through a special test. As long as you purchase the 6GB Kit or the 4GB module we list on our MacBook/MacBook Pro unibody memory page, use our 'MyOWC' guide, or only purchase 4GB modules where we list these 2008 Unis as compatible - you will have no problem.

The same also applies to all MacBook Pro 2.4GHz Unibody models, including those shipped after March 2009. However - the other speed MacBook Pro models that got updated in March/2009 are actually a-ok for up to 8GB. Initially Apple had shown their 8GB kits as approved for them, but then pulled that - and I believe may have had to do with confusion related to the 2.4GHz model which was also in the same 15" line up. Easier to just keep the limit at 4GB than to try to explain and also have to determine which model which customer has. For all the MArch/2009 models - our listings and guide are clear on what we have certified for what upgrade options.

All MacBook Pro 17" unibody models have always had Apple support for up to 8GB.

All June/2009 introduced MacBook Pro 13" and 15" models (SD Card Slot equipped) also have always had Apple support for up to 8GB.

While recent firmware updates (wasn't 10.6 that did it.. but happened right before 10.6 came out) did enable the Mac mini models to utilize a full 8GB vs. the 4GB prior 'hard' limit, this is not the case with any of the 6GB limited MacBook/MacBook Pro unibody models which do have a hardware related limitation.

hope this helps.

- OWC Larry

First I can confirm, no go. MBP Late 2008 with 10.6.2. Always when you think, looks like its working now, paff ..kernel panic. Also the 9600 trick doesn´t work. I bought the Hynix original RAM. Really a pity, who will think before that sth like this can occur. Question now is only will this be fixed by a later SL Version?

I had a similar issue. When I first upgraded to Snow, my MB was running very slowly. I thought it was a RAM issue so I upgraded from 2GB to 4GB. The RAM came from a MBP.

I was then getting kernel panics. I reinstalled the RAM, making sure it fit snugly. I did a SMC reset.

So far everything has been working smoothly. I did a kernel panic watching a streaming movie and on my iDVD player. Strange.

I've tried to be pretty clear on this... unless the 4GB modules have been screened for use in 2.4GHz Unibody 15"/all 2008 Unibody - it's hit or miss. Doesn't matter if it's Samsung original, Hynix original, etc. Passing Apple's hardware test doesn't mean they are good in the unsupported config. We put together a specific screening test which does reveal those that are a no-go and those that are A-OK for these 'upgrade limited' unibody models.

No Apple OS or firmware update is likely to change this. That said - we are able to supply parts that do work for 5GB/6GB configs in these 'official' 4GB supported models. We specifically offer parts with this screening and listed with said compatibility and they do work.

It's frustrating as we learned since can have 2 identical Hynix or Micron or Samsung FACTORY Original modules that also work together (or separately) flawlessly in a Mac that supports 8GB. But try them in a 4GB 'Apple Max' 2008 model unibody - and one will pass and work fine with never a even the slighest hiccup, the other will Kernel Panic consistently and repeatedly on same test. Both modules can be from the same factory production run, look absolutely identical - no explanation for why one has that extra tolerance needed for the 2008 unibody to take it to the 6GB max vs. the other not so.

Any way - I've said about all there is on this and trying to help. This comes from tried and true experience. We know what works, what doesn't work, and why what works works. 🙂

hey, i don't know if anyone else has heard this, but i figured i would pass it on. I guess if u run your comp at 64bit and update your firmware. 1.8, or something like that. i came out recently, and was meant to stop the dvd noise...which it didn't, but if it allows us to get a little more giddyup for our buck (in the form of more ram) its definitely worth it. I wasn't sure if anyone else had heard this. Dahde, if you would be willing to email me a link to your blog it would be much appreciated. ive been doing a ton of research, so i figured id share the wealth. Btw, is anyone else running a macbook pro 5,1 2.8ghz?

Forgot to add, according to what ive been reading, these new updates allow for 8gb, not just six! i wasn't sure if anyone could verify. i heard that i might heat up tho, on the downside. but from what i could find, all the ram seems to heat up to the same degree(according to the manuals), so I don't know if that helps any body but hopefully its a good sign.

Message was edited by: DoubleEdgeE2

the latest 1.8 Firmware update does not in any way impact the Late 2008 'Unibody' MacBook and MacBook Pros in terms of being able to utilize more than 6GB of installed memory.

All 2008 Unibody models, all MacBook 13" Aluminum Unibody Models(not the Pro or White), and the MacBook Pro 15" unibody 2.4GHz March 2009 model are limited to 6GB maximum. 4GB Apple officially supported and OWC Labs 'MaxRAM' certified to 6GB.

Note - these 6GB limited models WILL report 8GB when you install 2 x 4GB. This is no different with the December 1.8 update vs. 9 months ago. And.. also no different - as soon as the system exceeds use of the first 6GB, performance nose dives - system slows to a crawl. 6GB is the maximum memory truly usable at this time and due to apparent hardware limitation. The same 6GB limit is also present on prior iMac and MacBook models from 2007-2008/2009 which have official support for 4GB - run great with up to 6GB - but slow down to a crawl with 8GB once 6gB exceeded.

I am hoping that providing a lot of information better than not enough...
========
These models all do support 8GB:
==========
March 2009 15" Unibody Models with processor speeds of 2.66GHz and 2.93GHz (these have ExpressCard Slots) have official Apple Factory notice of up to 4GB memory supported, but are fully OWC lab 'MAXRam' certified for up to 8GB with the same 8GB kits that are utilized for '8GB Apple recognized' spec models.

All 17" Unibody Models - All 13" MacBook Pro Unibody Models (June/2009 intro - have FireWire 800) - All 15" MacBook Pro SD-Slot equipped Unibody Models (June/2009 introduced - prior models have ExpressCard slot..don't get me started on that downgrade...) === have all always had official Apple factory 'officiated' support for up to 8GB of memory installed.

Always happy to answer questions owc@macsaales.com. We also covered this in our blog: http://blog.macsales.com/ recently and prior as well.

- OWC Larry