well the chipset is capable of 8gb, but something stops it from working reliably with that much in it, the most that can be used reliably is 6gb from what ive read on here
Snow leopard may change that, it would be interesting. I couldn't afford 8gb of ram anyway but it would be nice to have. Ill put 4gb in at some stage as its a little stretched using parallels on the stock 2gb.
Well, I for one haven't been able to upgrade my Late 2008 MacBook Unibody 2.4 GHZ 13" beyond 4 GB RAM even with Snow Leopard installed. I ordered 2 4 GB RAM modules from OWC and have tried all possible combinations of 6 and 8 GB along with the original 2 GB modules without success. I even tried a clean installation of Snow Leopard from a USB drive and neither the 6 GB nor the 8 GB configuration completed the process without my having to perform a forced shutdown. Does anyone know if there's a preferred slot for the 4 GB module in a 4 + 2 (6 GB total) configuration?
The limiting factor seems to be the graphics chip, since in most cases where a restart is required the screen saver had just activated. I've also got a Boot Camp partition with Windows 7 Ultimate Build 7600 installed, but the Windows Desktop Manager keeps dropping and the display reverts to a Basic theme whenever there's a glitch. However, Windows 7 seems to recover better than the Mac OS X, never requiring a forced shutdown.
Did you try forcing snow leopard to boot in 64 bit mode when you tried the 6 and 8 gig ram? Snow leopard boots with 32 bit on default, you have to hold dow 6 and 4 key to boot to 64 bit. Maybe booting into 64 bit may make a difference?
Thanks for all the advice, I appreciate it!
I contacted OWC Tech Support and they asked me to rub the contacts with an eraser and try it again, but to no avail. I'm now going to insert the 4 GB RAM sticks individually and try to isolate the fault to one of them or a particular slot.
From what I've read this model is restricted to a max of 6 GB due to a firmware limtation, so I've given up trying to get 8 GB out of it. But if I could at least get it to work with 6 GB that would be fine for a Windows 7 virtual machine allocation.
I've also tried booting up while holding down the 6 and 4 keys but Snow Leopard refuses to start in 64-bit mode on this machine no matter how much RAM is installed. Don't quite know what to make of that.
Well, I tried inserting the 4 GB sticks individually this morning while leaving the second slot empty for a 1 x 4 GB configuration to test each stick separately. Guess what? The system froze regardless of which modules was inserted or in which slot I'd placed it. I conclude that neither of the sticks are compatible with my system and have asked OWC for a refund.
Unfortunately, based on these results I cannot provide any information as to whether this model supports 8 GB RAM with Snow Leopard. Sorry!
OWC has authorized a full refund without question and is honoring their Service Level Agreement, provided I return the sticks within 15 days of the purchase invoice. My compliments to a great team who were quick to respond to my e-mail queries and who I would highly recommend even though the modules shipped weren't compatible with my system.
This morning I stopped off at the Apple Store here in Berne where I purchased the notebook to chat with my favorite salesman, who remembered me right off even though it's been 8 months since I last saw him. I asked him if Apple was still supporting a maximum of 4 GB on the MacBook Unibodies and he took a look at the catalog in his system to check. To my surprise, he informed me that my model could be upgraded to 6 GB and ran downstairs to see if he had any 4 GB sticks in stock. There weren't any, of course, but I was astonished to hear that he could order one for about the same price that I'd paid for my OWC sticks! Not only that, but he promptly ordered 2 "just in case" and offered to have a Genius perform the upgrade for me at no additional charge. Pretty impressive!
Needless to say, I'm looking forward to upgrading my Collector's Edition and enjoying it for years to come!
ssn, thanks for posting your experience! I just want to throw my own into the mix: it's identical to yours. I finally caved and ordered a 4 GB stick from OWC, and it arrived this afternoon. It took me till I hit just over 4 GB usage on my RAM to get a kernel panic, and I tried in both a 5 GB (4GB + 1 GB) and 6 GB (4 GB + 2 GB) configuration... after a couple of times I got it to get well into 5 GB used, and realized that this definitely wasn't a stupid addressing limitation or anything like that.
Then I read your post, and I was nearly excited to reconfigure with *only* the 4 GB stick to find that the same thing has happened to me--kernel panic after a few minutes of being on and taxing RAM (opening Aperture, Parallels).
So, I guess I'll get my $300 back for this experience, and thanks much for your post--it saved me some time. I'm looking forward to hearing about how the Apple-supplied RAM works for you.
Apparently users have reported that their 6 GB RAM configurations worked fine with 10.5.8 but are suffering from lockups with Snow Leopard. Could be that the RAM supplied by OWC was perfectly good but Snow Leopard doesn't work well with it for some reason. I'd hate to go back to 10.5.8 now just to find out but since I haven't done much with my system since the clean install of Snow Leopard I'm tempted to try it out. After all, 6 GB of RAM is worth more to me than the current version of 10.6. I may even try a clean install of the system with the original 10.5 disk with 8 GB inserted just to see what happens!
Who would have suspected that Snow Leopard has an issue with 6 GB of RAM?
Good thoughts. My weekend is stacked, but given that I am stuck with this RAM till I can return it on Tuesday (Monday is Labor Day in the US, postal holiday), and that I have a spare partition on my backup drive, I'll put 10.5.8 on that and re-do the tests as best I can.
If that works, I'll hack my MacBook to boot 64-bit as per the suggestion, and maybe that will work. Probably my sound driver won't be available in 64-bit or something stupid like that, too....
Wow, I didn't know you still had your RAM stick, this is great news! Let me know how the testing goes with 10.5.8 this weekend if you find the time. If you find that Snow Leopard is the issue then I won't bother testing mine. I haven't sent my modules back either and I'll keep them in that case for future use. Wouldn't be fair to blame OWC for this issue if the memory they provided isn't defective.
Now let's see if the Apple-provided RAM does better with Snow Leopard...we'll know as soon as it arrives at my local Apple Store!
Well, I am not sure if to be relieved or disappointed, but I did a fresh install of OS X 10.5.8 on my backup drive's spare partition, and booted into it with the 6 GB (4 + 2) configuration. I compiled this tool for 64-bit with this command
gcc -arch x86_64 -o eatmem eatmem.c
and ran it a few times with various RAM allocation sizes. It was irritating, I never could get the OS to allocate more than just slightly over 4 GB (it paged/swapped out the rest before killing its physical memory), but sure enough after I allocated 6 GB of RAM total and then went to kill the terminal window (parent of all the eatmem processes), it kernel panicked. It did this a couple more times. I tried the 4 GB single-stick configuration, and same results: kernel panics galore. Finally, I put my 4 GB (2 + 2) configuration back in and it weathered allocating tons of RAM quite happily, no hints of any instability (other than being really, really slow), indicating that the problem is probably not with the memory allocation program.
I did try to 'hackintosh' my way into a 64-bit kernel running on the MacBook, but I was defeated in getting the USB stick to boot and do its trickery. That said, this RAM *should* have worked in 10.5.8, so it's likely that it's just incompatible... even though that doesn't make much sense to me.
The Apple Store called today and I dropped over to have the 4 GB RAM stick installed that they'd ordered. The tech inserted and tested the RAM for me before I picked up the MacBook this afternoon.
Unfortunately, as soon as I got home and started working a bit with the system I again experienced lockups and had to force shutdown several times. The 6 GB configuration doesn't seem to be stable in Snow Leopard at all (the 4 GB stick is on top and the 2 GB module underneath). So I'm now doing a clean installation of 10.5.8 to see if that helps. Will let you know what happens, but I'm afraid 4 GB seems to be the max at least for me.
The tech told me not to get my hopes up about a firmware update from Apple to boost our machines to allow 8 GB max RAM if they don't support them now. Bummer...
Man, that's no fun. And what a pointlessly stupid regression if true. I was pretty surprised when my stick failed in 10.5.8, though, so I definitely can't contribute useful data. MacSales is sending me a replacement to test out, so I will check that one on leopard as well, assuming it fails with Snow Leopard.
My only hope is that this may not really be firmware related--Honestly, I don't think it is. Given that many people have found that 6GB works in Leopard, if it doesn't work in SL, that's a STRONG suggestion that the fault lies with the operating system. If that's the case, then there's a good chance that it's in the kernel and the way it interacts with the hardware. I really think it could be that a 64-bit kernel might solve the problem of the RAM limitation, at least the new 6 GB one. In that case, we may see Apple allow 64-bit kernel on the MacBooks down the road as more 64-bit device drivers come out--or someone comes up with a nicer hack than the one that's out there right now.
ssn, with that Apple 4 GB stick please be sure and try it in Snow Leopard by itself (4 GB single-stick configuration) to confirm whether it's OK by itself. This will help determine whether this is an issue with addressing in a single bay or a more absolute RAM cap.
OK, I went ahead and checked the 4 GB RAM module provided by Apple on its own (1 x 4 GB configuration) while running Snow Leopard and the system suffered a kernel panic within minutes. The hard drive was clicking a lot just before the lockup and I'm beginning to wonder if this may be a factor, since I've installed a 750 GB Western Digitial 12.5 mm SATA II unit.
I was also able to unlock the 64-bit Kernel restriction on the Unibody MacBooks by following the instructions given in this blog:
I had to make some adjustments to the original instructions (see my feedback comments) to prevent the system from defaulting back to a 32-bit startup kernel. Although I was overjoyed at being able to start up in 64-bit kernel mode, the system again locked up when I tried surfing with 8 GB RAM installed. Some users had reported that their late '08 MacBook Pros were 8 GB RAM capable in 64-bit mode, but this doesn't seem to be the case with the Unibody MacBooks.
I'm now doing a reinstallation of Snow Leopard with the original 4 GB RAM (2 x 2 GB) inserted and will first complete any software installations needed to get the system operational before swapping out various RAM configurations again. I'm hoping to have better luck in 64-bit mode with at least 6 GB RAM!
Thanks for the tip; I hadn't seen that particular hack to get a 64-bit kernel. I've got it working now, too, and it looks like I'll be sticking with 64-bit... Parallels was updated to work with the 64-bit kernel and I don't print from this machine, so I think I'm set on non-64-bit drivers.
I'll do my own tests with the 64-bit kernel when the new 4GB stick arrives.
OK, let me know how your testing goes...would be great if we could get these notebooks running with 8 GB RAM, or at least 6 GB! You're obviously the expert here, I was just too proud to have gotten that 64-bit kernel working (had to look up some Mac OS X commands before trying).
The MacBook seems to be running snappier in 64-bit, and I even got the printer to work with it. Paragon NTFS for Mac OS X 7.02 Beta doesn't support 64-bit, however, and I'll be using the Beta version of Parallels to run my VM for the moment, but both of these solutions are surely temporary.
Maybe Apple will be gracious enough to provide a firmware update for us so we can take advantage of that extra RAM. These Unibody MacBooks are great machines if you don't need firewire and I love working with it.
Well, Here I am on my Macbook 5,1 in Snow Leopard with a 64-bit kernel and 6 GB of RAM installed. This test has been really, really, really odd. I booted up, and used eatmem to eat 6 GB of RAM across 3 calls. This pegged out my system, got me a huge page file, and other than being doggishly slow, things were running just right. Then I killed that and freed up the RAM, which is actually the point where I usually saw the kernel panics happen with the 32-bit kernel. Then I ran Parallels and Aperture. Man, Aperture is sweet with that much RAM, it really doesn't skip a beat!
Anyway, things ran great for about 50 minutes. Then, out of nowhere, Skype crashed on me. It wouldn't relaunch, either, just kept crashing during launch. Oddly, the crash reports showed some random unhandled exception rather than what I'd have expected--segfault. I tried to open up other random apps (iCal was first)... Those all crashed on startup, and now they were all segfaulting on startup. I quit all open apps (other than Finder), and tried to relaunch them. No dice, more segfaults. At this point, I was expecting a kernel panic any moment, but it sure never did. I gave up and rebooted, and that's where I am now, still with 6GB loaded.
I really don't think this is a firmware issue. It sounds like a kernel/kext issue, which would account for why switching kernels yields better results.
For what it's worth, this is with my initial stick of RAM from OWC/MacSales. They're sending me a box to return it in exchange for a replacement, which I will test with as well. I also need to check this stick out running solo (4GB single stick alone), assuming that I get it to break again in this session.
OK, maybe anything greater than 4 GB is a problem with SL, which would correlate to the other reports of users having suffered kernel panics after upgrading from Leopard with 6 GB of RAM. The RAM modules themselves seem to be compatible...even the one I received directly from Apple crashed.
Our best bet may be to stick with 2 x 2 GB at the moment and try again when 10.6.1 is released.
I wonder how others are faring with the newer MacBook Pro models and 8 GB of RAM using Snow Leopard? If they're not reporting any issues then there may be a problem with an asymmetric configuration.
I'll be installing Windows 7 in Boot Camp tomorrow to test the Apple provided 4 GB module on that side in combination with another 4 GB and 2 GB stick.
Update: Still suffering kernel panics with 6 GB RAM installed, both Apple-provided, after updating to 10.6.1. Windows 7 handles the extra RAM better, but I did suffer one BSOD when transferring data between a USB HDD and the system. I've gone back to 4 GB until someone finds a solution.