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GDITheman

macrumors newbie
Original poster
Sep 21, 2008
5
0
I just bought a new macbook. It is the mid range white model. It came with 2 gig of ram and I bought (2) new 2 gig modules to replace the (2) 1 gig modules.

The macbook will only start up with (1) 2 gig and (1) 1 gig installed. It will not boot up with both 2 gig modules installed. I swapped out the 2 gig modules to see if one was one of them was bad. Didn't matter which one of the 2 gig was installed with the 1 gig chip. They both booted up and checked OK.

The memory is Corsair Gaming Memory 2 gig DDR2 800 MHZ. Does anyone know why the macbook won't boot up with both 2 gig modules installed?

Thanks
 

hogfaninga

macrumors 65816
Aug 16, 2008
1,305
0
Chestnut Tree Cafe
I just bought a new macbook. It is the mid range white model. It came with 2 gig of ram and I bought (2) new 2 gig modules to replace the (2) 1 gig modules.

The macbook will only start up with (1) 2 gig and (1) 1 gig installed. It will not boot up with both 2 gig modules installed. I swapped out the 2 gig modules to see if one was one of them was bad. Didn't matter which one of the 2 gig was installed with the 1 gig chip. They both booted up and checked OK.

The memory is Corsair Gaming Memory 2 gig DDR2 800 MHZ. Does anyone know why the macbook won't boot up with both 2 gig modules installed?

Thanks

I don't think that RAM is compatible with your Macbook.
 

owdin

macrumors member
Jul 22, 2008
56
0
Belgium
I just bought a new macbook. It is the mid range white model. It came with 2 gig of ram and I bought (2) new 2 gig modules to replace the (2) 1 gig modules.

The macbook will only start up with (1) 2 gig and (1) 1 gig installed. It will not boot up with both 2 gig modules installed. I swapped out the 2 gig modules to see if one was one of them was bad. Didn't matter which one of the 2 gig was installed with the 1 gig chip. They both booted up and checked OK.

The memory is Corsair Gaming Memory 2 gig DDR2 800 MHZ. Does anyone know why the macbook won't boot up with both 2 gig modules installed?

Thanks
The RAM for the Macbook should be 667Mhz.
 

GDITheman

macrumors newbie
Original poster
Sep 21, 2008
5
0
The box says it is backwards compatible to 667mhz.

This memory was chosen by the Geek Squad. Maybe I should just take it back. I am running w/ 3 gig right now ((1) of the original 1 gig and (1) of the new 2 gig) and the system is running faster. the memory also says it checks out in the hardware over view.

Thanks
 

hogfaninga

macrumors 65816
Aug 16, 2008
1,305
0
Chestnut Tree Cafe
The box says it is backwards compatible to 667mhz.

This memory was chosen by the Geek Squad. Maybe I should just take it back. I am running w/ 3 gig right now ((1) of the original 1 gig and (1) of the new 2 gig) and the system is running faster. the memory also says it checks out in the hardware over view.

Thanks

My advice is to never take the advice of the Geek Squad especially concerning Apple products.
 

aleksandra.

macrumors 6502a
Sep 13, 2008
674
0
Warsaw, Poland
My advice is to never take the advice of the Geek Squad especially concerning Apple products.

My experience with my PC tells me it doesn't matter whether it's Apple's or if it's Geek Squad or similar "experts" (obviously my experience is mostly with the latter, but I've hear enough about the former not to see much difference). Just don't, especially if they want you to buy something from them. If it's just general piece of advice, it might actually work.
 

GfulDedFan

macrumors 65816
Oct 17, 2007
1,063
23
Indiana
This is a know issue that has been written up in several forum posts. It seems that 2 x 800 MHz have a problem, 1 800 MHz + 1 667 MHz is no problem, and 2 x 667MHz is no problem. The reason is not been made clear to me as of yet but this has been the end result.

My advise: use the 667 MHz chips. -GDF
 

austinrut

macrumors newbie
Jul 4, 2010
1
0
same problem

I'm having pretty much the same issue, except that I'm installing 667 MHz RAM. If I install both modules (PNY) then my macbook won't boot (I don't even hear the 'chime'). If I leave on of the old 1GB modules and just one of the new 2GB modules then it boots fine (doesn't matter which new module).

Pretty baffled!

I've heard all over the place that RAM must be balanced to work efficiently... plus I freaking paid for 4 GB of RAM. Both modules seem to work properly when paired with a 1 GB, but not when paired with each other.
 

chriszeller

macrumors newbie
Feb 8, 2011
1
0
Same Problem

I'm also having this problem. Additionally, I have noticed that the machine will not boot with even just one of the 2gb sticks inserted. However any combination of using the old 1gb and new 2g sticks works fine. Is it possible that there is something in the boot sequence that checks for a serial in the memory or something similar?
 

Jesseeee

macrumors newbie
Feb 9, 2011
17
0
United States
Solution

The reason why it works with 1 old stick and 1 new stick is that your EFI is reducing the clock speed of the new stick (800MHz) to match that of the old (667MHz). There is a solution for this that allows you to use both new sticks.

https://forums.macrumors.com/threads/465127/

Note: this is technical and requires that you have windows installed.
 
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