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I honestly don't see why not. Apple specified an official limit of 4GB for both the 2.4 and 2.53; and they were both released at the exact same time. The only differences are the CPU speed, GPU memory, installed RAM and hard disk size and none of those should have any impact on supported RAM. And I don't see why Apple would bother to keep the firmware for the two logic boards different.

So assuming this is indeed a late '08 MBP that has 8GB of RAM working and is working well, I'd say that theoretically, 2.4GHz owners should have reason to celebrate too.

Apple originally listed 2.4GHz as not possible for 8GB ram. Not sure if that's changed. The 2.53GHz randomly showed up as 8GB capable on Apple's upgrade parts site but there was speculation to which revision it referred to.

I found a app called rember, http://www.kelleycomputing.net/rember/, which runs memtest which is a app that runs a bunch of test to test and find problems with your memory. Thought I would download and try it out and see what it does. So I ran it and opened activity monitor to see how much ram it was using. Activity Monitor reported 7.98gb of ram being used, memtest using 6.05gb. System stayed very stable and very responsive. Below is a screen capture of Activity Monitor from grab showing 7.98gb ram being used.


I would like more info on piggy app please before I ask someone to send it to me and run it on my system.

Piggy is unnecessary since the Rember program clearly shows that you were able to execute more than the 4GB ram barrier that was originally established. Now the question remains is that, is it because the 64-bit kernel allowed this or does the kernel not matter and it's the firmware?
 
Apple originally listed 2.4GHz as not possible for 8GB ram. Not sure if that's changed. The 2.53GHz randomly showed up as 8GB capable on Apple's upgrade parts site but there was speculation to which revision it referred to.



Piggy is unnecessary since the Rember program clearly shows that you were able to execute more than the 4GB ram barrier that was originally established. Now the question remains is that, is it because the 64-bit kernel allowed this or does the kernel not matter and it's the firmware?

I will test it in 32bit mode little later and post my results shortly after. Thanks for everyones help and insight in testing these, glad I can help clear up this.
 
32bit mode

32bit mode is a mixed experience. The system was able to see all 8GB and rember was able to go past the 4GB barrier. But the system, even when rember was not running, seemed noticeably slower and seemed like it was struggling, the system did not crash though. Boot back into 64bit mode everything is running fine again. So I would say 64bit kernel mode has something to do with it, and if you really need 32bit mode do not install 8GB of ram yet, unless Apple releases a firmware update or something to officially support it. If you can run 64bit mode all the time go for it. Sorry know these are not the results lot of people wanted to hear, just reporting truthfully my experience.
 

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jfs, if what you are saying is true - that the limits are via the OS and not the firmware, then it MAY just be possible for a penryn 2.4GHz MBP to support 8GB under SL (i bought it yesterday). intersting.
 
jfs, if what you are saying is true - that the limits are via the OS and not the firmware, then it MAY just be possible for a penryn 2.4GHz MBP to support 8GB under SL (i bought it yesterday). intersting.

It would probably work if you can stay under the 64bit kernel extension mode. 32bit is shaky, in my experience.
 
No by default goes to 32bit. I use a program I found online called 32 or 64 bit kernel startup mode selector http://ahatfullofsky.comuv.com/English/Programs/SMS/SMS.html

i saw that program floating around, the Penryn machine is a 4,1 - and 64-bit is "supported" according to that program's info section. excellent!

8GB for this machine has been reported to be noticed, so i will save up and get it. i am excited! thanks jfs
 
jfs, if what you are saying is true - that the limits are via the OS and not the firmware, then it MAY just be possible for a penryn 2.4GHz MBP to support 8GB under SL (i bought it yesterday). intersting.

Actually, the system being slow is just SL being retarded for a vanilla OS and most likely not the 8GB's fault. But the OS didn't crash, so the Late 08 2.53GHz models are supported for 8GB.

However, it works in 32-bit, therefore, the system's firmware allows it.

I highly doubt the Penryn models can run 8GB even with the 64-bit kernel but it could be possible.
 
No by default goes to 32bit. I use a program I found online called 32 or 64 bit kernel startup mode selector http://ahatfullofsky.comuv.com/English/Programs/SMS/SMS.html

You can also just update the com.apple.Boot.plist in the /Library/Preferences/SystemConfiguration folder. There should be a Kernel Flags key and you just add "arch=x86_64" between the <string> tags. Either way, thanks for checking into this for me, it makes me feel happy that us early adopters didn't get screwed!
 
Actually, the system being slow is just SL being retarded for a vanilla OS and most likely not the 8GB's fault. But the OS didn't crash, so the Late 08 2.53GHz models are supported for 8GB.
are you sure? jfs seems to be pretty sure that the 64-bit thing fixed his issues.

However, it works in 32-bit, therefore, the system's firmware allows it.

I highly doubt the Penryn models can run 8GB even with the 64-bit kernel but it could be possible.

if the hardware can support 6GB then 8GB should be possible - its just common knowledge, since when does hardware support wierd numbers? (e.g. hardware has 4GB limits, or 8GB limits, or 16GB limits - nothing in between). that leads me to believe that if 6GB is supported then 8GB will be supported (provided the OS will of course).
 
are you sure? jfs seems to be pretty sure that the 64-bit thing fixed his issues.

I don't even know what his real issues are. He just stated it was slower and harder in the response area. That doesn't really mean the kernel has issues with his ram.

if the hardware can support 6GB then 8GB should be possible - its just common knowledge, since when does hardware support wierd numbers? (e.g. hardware has 4GB limits, or 8GB limits, or 16GB limits - nothing in between). that leads me to believe that if 6GB is supported then 8GB will be supported (provided the OS will of course).

Normally I'd agree with you, but other OS such as Linux and Windows 64-bit has failed in previous testing also.
 
Should someone report this to MacRumors and MacSales? I think this might be good information, we've just got to keep testing a little more.
 
I don't even know what his real issues are. He just stated it was slower and harder in the response area. That doesn't really mean the kernel has issues with his ram.

Normally I'd agree with you, but other OS such as Linux and Windows 64-bit has failed in previous testing also.

i guess the only real way for me to find out is to try it myself. its rather expensive though so i may be a while saving.
 
If you can run 64bit mode all the time go for it.

How do you mean if u can? If your laptop supports 64bit? Or in 64bit do all your programs have to be 64bit.

Also I'm confused I assume I'm running 32bit kernel but how can safari etc run in 64bit, is it really 64bit?
 
There's a lot of pages so I didn't read through all of them. Hope it hasn't been answered..

If I have 2x1gb ram already installed, could I just replace one of them with a 4gb stick = totaling 5gb?
 
There's a lot of pages so I didn't read through all of them. Hope it hasn't been answered..

If I have 2x1gb ram already installed, could I just replace one of them with a 4gb stick = totaling 5gb?

Yes but you loose dual/tri channel
 
How do you mean if u can? If your laptop supports 64bit? Or in 64bit do all your programs have to be 64bit.

Also I'm confused I assume I'm running 32bit kernel but how can safari etc run in 64bit, is it really 64bit?

It has been reported and software companies have issued statements that some software will not run, or run properly, under the 64bit kernel mode, example that has been brought up here a lot VMWare or Parallels. I meant it in more of if the software you needs will run properly under the 64bit mode then do it and run in 64bit mode all the time.

As far as 32bit kernel mode and safari and other programs running 64bit I am not exactly sure how that works either, so I will not comment on that

As for the 8GBs of ram under 32bit mode the system seen it and was able to address it as I showed in previous post, but the system really slowed down to a crawl and was struggling and apps where having a problem opening. The system did not crash but I have a feeling it might have if I did not reboot back into 64bit mode. Even if the system did not crash I could not use the system on a normal basis with that much shakiness and slowdown, nor would anyone want to that needs to run VMWare or Parallels, I do not think it would run good at all even though it could address all 8GB of ram. No I have not tested those 2 programs but from my experience of how really slow the system became it would think it would be a bad user experience, if it ran at all or if it didn't crash the system. I was having trouble even coming on to this forum and posting my test results under 32bit mode, I rebooted into 64bit mode and posted.
 
i'm send a email to macsales
Hello Mac Sales.

Can you check againg to run 8GB ram in late 2008 mbp using 64bit kernel ?
someone from macrumors just checked to run 8gb ram in 2.53 late 2008 using 64bit kernel, and its works.
This is the link
http://yit.me/6ypws3

its will be great if someone from macsales confirm it too.

Thanks

and

they are replied
We currently only find that the unit is stable with 6GB of RAM in the unit. The issue that that person will run into is when he tries to address the whole 8GB of RAM....it is not stable. 6GB is the max that unit will support and be stable.

Thanks,
Joshua Taylor
Tech Support
Other World Computing, Inc.
 
im lost. i have a macbook pro 4 1. it currently has 4gb of ram, can it support 8gb? also, can it support the GeForce 9600M GT, it currently has the GeForce 8600M GT.
 
im lost. i have a macbook pro 4 1. it currently has 4gb of ram, can it support 8gb? also, can it support the GeForce 9600M GT, it currently has the GeForce 8600M GT.

the 8GB RAM issue is not fully known yet. to find out you will have to DIY.

you cannot upgrade the GPU inside the MBP. :(
 
Oh noez. Maybe I dont understand the guide completely. But. Well. I did just wake up. Maybe thats why.

But anyway. My MacBook Pro is a late 2008 15 inch that I got in febuary 09.

It was.

2.53 GHz Intel Core 2 Duo

4 GB DDR3 RAM

320GB 5400 rpm HDD (downgraded to 250GB 7200 because it was faster and took off 50 dollars)

Nvidia Geforce 9600M 256 MB (shared memory)

Nvidia Geforce 9600M GT 512 MB dedicated. (or whatever)

I remember seeing my 2.53 GHz model on the upgrade to 8GB list. But It was removed when the 2.66 15 inch came in and replaced the 2.53.

But does that mean I can still put 8 GB in mine some day? I kind of plan on keeping this Macintosh for a long long time. Like 6.. 7 or maybe 8 years. If it will stay alive or fast enough for that long.

I would be happy with a 6 GB cap... but 8GB would sure be nice :eek:
 
I have an Early 2008 Macbook pro 4.1 with 2.5 ghz.
I am trying to decide on upgrading my memory to either 4 GB with 2x2 gb sticks or to upgrade to 6 gb with 1x4 gb and 1x2 gb stick.
Question is: Would it be better to stick with the 4 gb so that I have the Dual channel ability or am I going to still see a significant performance boost without dual channel but 6 gb. Anotherwords... which will be faster?
I do quite a bit of VM stuff, but also just like having TONS of programs open at once between multiple monitors and lots of multi tasking.
Will also be upgrading to an SSD in the near future if that will play any role in the decision.
 
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