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RAM upgrade from 1066 to 1333 MHz

Hello there,

I own a MacBook Pro 13' 2011 and my wife has a MacBook 13' Unibody late 2008. I recently upgraded the RAM of my MBP from 4GB to 8GB, but my wife only has 2GB in her MB.

The RAM of the MacBook is : 204-pin PC3-8500 (1066 MHz) DDR3 SO-DIMM

The one of my MacBook Pro is : 204-pin PC-10600 (1333 MHz) DDR3 SO-DIMM

My question is, can I put my old 2x2GB 1333MHz in her 1066MHz RAM slots without any problem ? Will it work ?

Thank you

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Hello, Ben. I personally have no experience doing this, but I've located a Mac post that discusses this in some detail. I hope this helps you. Good luck.

https://discussions.apple.com/thread/333...

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Hi rj. Thanks for the link. So the faster RAM will run at the slower bus speed without causing any problem ? I know that the 1333MHz ram will not run as it was designed and won't all it's power but I already have it and I don't want to buy other ones. Can anyone can confirm this ? Thanks

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Ben, I didn't see anyone who said that it wouldn't possibly cause problems. Sometimes faster RAM will work and sometimes it won't. If you start having problems with unexplained crashes or kernel panics, replace it with the correct speed.

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Hello mayer, he did reply but it seems that he deletes its comment. Ok but it's not risky right ?

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I think the risk is minimal but watch the heat. I have actually burned my fingers on the wrong RAM.

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Thanks I will !

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Since I just tried this a few days ago, I'd thought I'd report my findings.

Test bed: Late 2008 Macbook Aluminum, DDR3 PC3-8500 RAM (1067MHz)

Tested RAM: DDR3 PC3-10600 (1333MHz)

Original RAM:

Bank 0/1GB 1067

Bank 1/1GB 1067

Remove both sticks of 1067 RAM. Install 2GB 1333 in Bank 0. Reboot - successful; all systems function normally. Swap 2GB 1333 to Bank 1. Reboot - successful; all systems function normally.

Mixed RAM:

Bank 0/2GB 1333

Bank 1/1GB 1067

Reboot - NO BOOT

swapped slots

Bank 0/1GB 1067

Bank 1/2GB 1333

Reboot - NO BOOT

Remove 1067 RAM. Reboot with 1x2GB 1333 - successful; all systems function normally.

Reinstall 2x1GB 1067. Reboot - successful; all systems function normally.

At least for the RAM I had (2x1GB 1067 Apple stock Samsung; 2GB 1333 HP stock Hynix), the system boots with all 1067 RAM or all 1333 RAM, but it will not boot if the two are combined. I have installed 2x2GB 1067 in the Macbook now, and I have 2x4GB 1067 arriving this week; I'll retest combinations with the 2GB 1333 and repost as soon as possible.

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+ I like hands on research

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As I mentioned in the Apple thread rj713 linked to above, I suspect there's a timing issue involved - the memory controller can handle downcycling the RAM, but it can't co-ordinate two different RAM speeds at the same time.

Given that the Late 2008 Macbook is the first of the DDR3 systems, it would be interesting if someone with a later 1067 RAM laptop (2009 or 2010) could try an experiment like mine with mixing 1067 and 1333 RAM, and report back on the results. It may be that the memory controller (if that's the issue) is the same in all generations of the DDR3/1067 era, or it may be that later memory controllers are smarter and more powerful.

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I have a mid-2010 White Macbook Unibody and installed 8 GB 1333 Ram into one slot and left the original 1 GB 1066 OEM Ram in the other. It is way faster than before. It has worked perfectly fine for me so far. The only weird thing is that when I look at the system information and see how much memory is installed it says one slot is 2 GB and the other is 1 GB. Not really sure why it doesn't recognize it as 8GB, but it is running at a speed that is definitely not only 3GB.

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Guys trust me I have been working for Processors manufacturing companies for quite a long. Always remember to check your processor before going for any ram upgrades or downgrades. RAM bus speed totally depends only and only on the Processor you macbook has. For example, if you have late 2011 13 inch macbook pro 2.4 Cori5, then simply go to the processor specification page. It clearly shows that it supports 1066/1333 MHZ pc3 rams. Now based on that you can upgrade or downgrade without even having a single inch of doubt. However, if you try to do any other experiment where you want to put in a higher bus speed or a lower bus speed ram than specified, then there are 100% chances that it wont work. Take my tip - whenever deciding for a RAM, get exact specs of your processor and see the RAM compatibility list as RAM is designed to serve processor only and it should be considered before buying any RAM.

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thank you so much this is the kind of reponse anybody wants !!! ...even now...years after...is so usefull to me :D

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Hi,

I have an Late 2008 MacBook and put in 2 x 4gb of Kingston memory. Both work at 1333. No problems at all!!

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Were you originally using by default 1066 rams and upgraded to 2x 4gb 1333 Coz that's the exact upgrade I want to get and I'm using same 2008 late model with 2 x 2gb 1066 rams.

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I have a MacBook Late 2008 ( Mac5.1) and I am running Yosemite 10.10.5

I bought 2X4GB DDR3 SO-DIMM 204 pin 1333MHz wishing to replace the 2 x 1 GB 204 1066 MHz RAM memory that came with my Mac.

Sadly, it did not work.

My Boot ROM Version : MB51,007D.B03

I think I am going to give it back to the shop.

If you have any idea, please, feel free to share it.

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I could only get 6GB to work, the bottom slot took a 4GB DIMM just fine, but the top slot would only recognize 2GB maximum no matter what I tried. I checked and all memory modules are fine. Did you ever resolve?

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@patwwods - First, make sure you system is able to support 8GB. Review your system here: MacBooks. The next thing is to make sure your systems firmware is upto date. Follow this Apple T/N: About EFI and SMC firmware updates for Intel-based Mac computers if the EveryMac listing states your system is able to support 8GB.

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yes assure your bios is at its latest possible version

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I have MB late 2008 installed Hynix 8GB = 4GB+4GB in each slot 204-pin PC-10600 (1333 MHz) DDR3 SO-DIMM

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i have a MB unibody mid 2010 running samsung 2gig 1333mhz on slot 1 samsung brand and on slot 2 samsung 1066mhz 2gig... and it works no hang no bottle neck no bluescreen... can anybody explain this running.. mac osx mountain lion 10.6 and win 7 via boot camp.

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I'm not sure what processor is in 2010 versions

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I just tried 2x4GB Corsair 1333 modules in a late 2008 unibody MacBook. The system booted and recognized 8GB of 1333 RAM, and everything worked until I tried to install OSX Lion. During the install process, I got kernel panics left, right and center. I had to remove the 1333 RAM and replace it with the old RAM. I don't know if there is something specific to operating system upgrades that would have caused the problem.

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this will sometimes occur if the system is reading the wrong time such as from a certificate open terminal and enter 09101713152017 as 09 10 17 13:15 this may or may not work but I try all

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I have a late 2008 macbook unibody and put 2 x 4gb 1333MHz ram in and it worked, but I do get occasional program crashes, especially for games. With 4GB 1066 ram it is fine.

There is a different firmware EFI update for the unibody macbook that allows it to work ok with 8GB ram, earlier updates will only support 6GB, any more causes constant system crashes. You do need a late version of Leopard at the very least to make it work as well. I think all 10.6 (Snow Leopard) variants work OK. To make things more awkward, Apple released the updated EFI with the same version number as the old one. You need version MB51.007D.B03 (look under boot ROM in system profiler). If you want more info look here: http://blog.macsales.com/9102-secret-fir...

In summary, use the 1066 RAM if you want a totally stable machine. In most cases it will actually be faster because it runs at the bus speed.

Chris

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hi,

i have a late 2009 macbook pro with 1067 RAM 2x2gb

I updated the mac book os to osx 10.7.3 nd tried installing 1333 ram but the system did not boot at all.

i agree that it must have something to do with the os.

regards

Vijay Singh Shokeen

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it's just the ram speed can't be more than the processors bus speed

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I have a mid-2010 Macbook Unibody (Macbook7,1) I had 2gb of ram to start with, so I wanted to upgrade to 4gb. I went out to grab 2x2gb 1333mhz ram sticks, It did not seems to work - no boot. Luckily I had my MBP lying around and it had 8gb 1067mhz ram preinstalled from Apple. I swapped out the ram from my MBP to have it working on my MB. Now my MB is running 8gb 1067mhz but I seem to be hitting some problems lately with alot of system crashes. Does anyone know if 8gb 1067mhz ram cause a system fault? or is it simply just a application failure. (I could not get any 2x2gb 1067mhz ram from where I live)

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Hi,

I have a late 2008 unibody aluminium macbook.

i want to upgrade to 8Gb(2X4)

My MB specs specify 1067 Mhz.

I´been told and read tons that with 1066 it works OK... !

can somebody tell me By own experience if this is true?

In the mac store i`ve been told that if you put a 1066 or 1333 it won't work appropriate because of the bus or something like that...

i am really confused, and don't know which one to buy!!

i really need to upgrade it, as my MB is SUPER SLOW since i installed Mountain Lion!!

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Zombie thread resurrection, but yes: I have been running 8GB 1067MHz DDR3 RAM (2x4GB) in my 2.0 aluminum Macbook for several years, without problems. My normal boot OS is 10.6.8, but I have used the same machine with Lion, Mountain Lion and Mavericks. I haven't booted it from Yosemite Beta 2 yet; I should try that today...

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always as rule use what the system was designed to use even if the faster ram does work you will see no speed gain since 1066 is rated accordingly to the system bus speed and may even hinder things

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I recently upgraded my Late 2008 Macbook unibody to 2xGB 1066 MHZ RAM it worked perfectly fine.. Looks like its better to keep at the 4GB level.

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I have a macbook A1278 2008 series. I bought my laptop from a friend with the trackpad not working, I had just ordered and installed a brand new one and it still wont work. It just clicks but absolutely no gestures. Anyone know how to get this fixed?

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You should have posted a fresh question (belatedly). As it wasn't seen hiding here.

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I am running 8 BG of 1333 RAM on my 2009 MacBook without it giving me a moment's problem. I am running the same 8 GB of RAM in this October 2008 MacBook Pro, (15.4 inch). Both seem to work just fine. However, when I tried to install the same 8 GB RAM into a 2010 Unibody MacBook, all it would to is whistle when I tried to boot it up. To me it's weird that a newer Mac won't run the newer RAM, but the older ones will. Does anyone have an explanation for this phenomenon?

The reason this MB Pro is running the 1333 RAM is because I switched its 8 GB of 1067 RAM into the 2010 MacBook. The MacBook is running 10.6 and the Pro is running 10.7.

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Did you update your EFI & SMC firmware? Follow this Apple TN EFI and SMC firmware updates for Intel-based Macs. Most likely your firmware is the issue not the memory.

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I'm running a Late 2008 MacBook Pro 2.5.3 Ghz, with 2 4GB 1333 Mhz chips.

It seems to run fast, and no problems, except, the fans are running a bit high, so it seems to me that the faster RAM is driving the heat up. I'm going purchase 1067 Mhz RAM, and swap them out to see if that reduces the heat and the fan.

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I would install a temperature monitoring app to see what sensor is running high here. The memories speed is not likely causing the heat issue.

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I have upgraded my 2011 MacBook Pro RAM from a Samsung 2x2GB DDR3 1333MHZ (4GB) to 2x4GB Corsair DDR3 1066MHZ CL7 (8GB) (Print on the front - DDR3 8GB MACMEMORY compatible to Apple iMac, MacBook and MacBook Pro - 2x4GB). Its running well, better than that, it's running great, however my question is that will this cause my RAM to overheat because it's at 1066MHZ while the system is designed for 1333MHZ? Don't know much about RAM. Thanks

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Take a look at About This Mac > More Info > System Reports then click on memory what is the speed your memory is running at? I suspect its 1067MHz. What most people forget here is the the memories I/O speed is the limit not what the chips are rated at. So in your case the chips heat will be the same or in fact a little lower.

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Dan, you the man, correct both 4GB DDR3 running at 1067 MHz. This just gave me the confidence to upgrade the RAM on my wife's iMac and my brother in-law's MacBook and older generation iMac.

Thanks

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downgrading ram should not cause issues

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I put a pair of 4GB DDR3-1333 SODIMMS from my dead MacMini mid 2011 in my Late 2008 Macbook 13" Unibody Aluminum (1066Mhz) and they seem to work fine. I reset the PRAM and the system boots properly, all 8GB of memory is properly recognized for OS X 10.10.5 Yosemite and Photoshop CC2015.5... YES!!!! WORKS!!!!

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I put my 4 X 2 GB RAM in my scooter, it runs very very fast, previously it doesn't start.

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Ben will be eternally grateful.
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