Can a Mid 2009 MBP Handle 8GB RAM in one Slot?

BaronvdB

macrumors 6502
Original poster
Oct 22, 2007
331
0
Hey Guys, quick question.

My MBP still works like a champ but one of my RAM slots quit working so even though I have a 4gb RAM stick in each slot it's only using 4GB.

My question is I believe the max RAM for this machine is 8GB so if I put a 8GB RAM stick in the one working slot will it actually use the full 8GB or is it limited to a MAX of 4GB per slot???

Thanks a lot!

Apple store wants like $300 to fix it so that's not an option. I'd rather just put that towards a new machine but since it still works fine I hate to buy a new one...
 

5to1

macrumors 6502
Mar 9, 2008
302
48
I assume you have tried switching the DIMMs over to make sure its the slot that's defective?
 

BaronvdB

macrumors 6502
Original poster
Oct 22, 2007
331
0
I assume you have tried switching the DIMMs over to make sure its the slot that's defective?
Yeah, I tried that first and no luck. Then I took to apple, they ran some tests and said the slot is bad...
 

5to1

macrumors 6502
Mar 9, 2008
302
48
Did they give any further details about the problem? Have they identified a specific hardware problem? Given the cost of a replacement logic board I'd consider giving it a clean, at the very least with some compressed air if you're reluctant to mess with it anymore.

Sorry I don't know if its able to accept a single 8GB DIMM. I seem to recall reading where someone had installed 2x8GB and the machine was able to address 8GB. But not sure if it was addressing 4GB on each slot, or 8GB of the first one.
 

BaronvdB

macrumors 6502
Original poster
Oct 22, 2007
331
0
Did they give any further details about the problem? Have they identified a specific hardware problem? Given the cost of a replacement logic board I'd consider giving it a clean, at the very least with some compressed air if you're reluctant to mess with it anymore.

Sorry I don't know if its able to accept a single 8GB DIMM. I seem to recall reading where someone had installed 2x8GB and the machine was able to address 8GB. But not sure if it was addressing 4GB on each slot, or 8GB of the first one.
I believe they just said I'd needed a new logic board. I'll try the compressed air thing but I don't have high hopes. Apple had in back for almost 30min trying different things with no luck...

If 8GB is the most the machine can use and IF it can use it all from one 8GB stick in a single slot than I'll be a happy camper b/c I won't be missing out on anything even though one slot doesn't work...
 

snaky69

macrumors 603
Mar 14, 2008
5,903
481
I believe they just said I'd needed a new logic board. I'll try the compressed air thing but I don't have high hopes. Apple had in back for almost 30min trying different things with no luck...

If 8GB is the most the machine can use and IF it can use it all from one 8GB stick in a single slot than I'll be a happy camper b/c I won't be missing out on anything even though one slot doesn't work...
I don't think it can, but I may be wrong.
 

BaronvdB

macrumors 6502
Original poster
Oct 22, 2007
331
0
Ok, well if nobody knows for sure I guess I could buy a 8GB stick and see what happens...
 

Altemose

macrumors G3
Mar 26, 2013
9,106
444
Elkton, Maryland
Hey Guys, quick question.

My MBP still works like a champ but one of my RAM slots quit working so even though I have a 4gb RAM stick in each slot it's only using 4GB.

My question is I believe the max RAM for this machine is 8GB so if I put a 8GB RAM stick in the one working slot will it actually use the full 8GB or is it limited to a MAX of 4GB per slot???

Thanks a lot!

Apple store wants like $300 to fix it so that's not an option. I'd rather just put that towards a new machine but since it still works fine I hate to buy a new one...
Try starting with one DIMM in the busted slot and see if it beeps. If it doesn't then you have a different issue.
 

BaronvdB

macrumors 6502
Original poster
Oct 22, 2007
331
0
Try starting with one DIMM in the busted slot and see if it beeps. If it doesn't then you have a different issue.
Tried this today. It beeps even with the RAM in the slot that's showing empty so I guess the slot is for sure dead. I guess the next step will be to buy and 8gb stick and see if it registers it.

Is there a way to know if it's actually USING all 8gb of RAM? I know it may show 8GB in the about this mac section but I would want to make sure it was using all the RAM and not some sort of 4GB limit per slot or something.

Thanks.
 

5to1

macrumors 6502
Mar 9, 2008
302
48
Is there a way to know if it's actually USING all 8gb of RAM? I know it may show 8GB in the about this mac section but I would want to make sure it was using all the RAM and not some sort of 4GB limit per slot or something.

Thanks.
Failing a simpler option, you could just start activity monitor and start launching Apps/memory intensive tasks. If memory pressure heads into the red around 4GB you have your answer, if it stays green until usage approaches 8GB its using it all.
 

BaronvdB

macrumors 6502
Original poster
Oct 22, 2007
331
0

Dovahkiing

macrumors regular
Nov 1, 2013
214
104
You could post the question of one slot capacity over on the Apple discussion forums. Some of those guys might be able to answer.
 

Eithanius

macrumors 65816
Nov 19, 2005
1,425
286
Did it work to use a single 8GB module in a mid 2009 MBP?
Hey Guys, quick question.

My MBP still works like a champ but one of my RAM slots quit working so even though I have a 4gb RAM stick in each slot it's only using 4GB.

My question is I believe the max RAM for this machine is 8GB so if I put a 8GB RAM stick in the one working slot will it actually use the full 8GB or is it limited to a MAX of 4GB per slot???

Thanks a lot!

Apple store wants like $300 to fix it so that's not an option. I'd rather just put that towards a new machine but since it still works fine I hate to buy a new one...
I have a Mid-2010 MBP 15" with 1066MHz DDR3 RAM slots which I've tested. As you all have known, anything before 2011 MBPs can only support up to 8GB Max RAM (sans the 2010 13" MBPs).

Last year I plugged in my colleagues' single 8GB DDR3 1600MHz onto my MBP, it boots fine, and the RAM speed down-clocked to 1066MHz. So in this case, it works on just one slot occupied.

Next I threw in the other 8GB onto the second slot for a total of 16GB and reboot, this time failed to boot.

Hope this helps… :D
 

magl

macrumors newbie
May 4, 2015
2
0
- This thread seems to suggest that it won't take a single 8GB module.
And that would be my guess as well.

Which specific machine do you have?

Also, as this is a quite old thread, perhaps you should start another one for your problem.
The machine I have is Macbook Pro 13.3" (Mid 2009) 2.26 GHz. The bank 1 stops working. Not clear to me a single 8GB won't work. Reply #14 indicates it worked for a 2010 MBP.
 

brdeveloper

macrumors 68020
Apr 21, 2010
2,499
162
Brasil
The machine I have is Macbook Pro 13.3" (Mid 2009) 2.26 GHz. The bank 1 stops working. Not clear to me a single 8GB won't work. Reply #14 indicates it worked for a 2010 MBP.
Get 8GB working on a single slot is trivial in the case of a 2010 Macbook Pro, since it supports up to 16GB. The 2009 MBP supports 8GB at maximum.
 

JTToft

macrumors 68040
Apr 27, 2010
3,405
754
Aarhus, Denmark
Get 8GB working on a single slot is trivial in the case of a 2010 Macbook Pro, since it supports up to 16GB.
- Actually, no. The 15" and 17" 2010 models only support 8GB. It's the 13" that does 16GB.
If you look at reply #14, you'll see 1x8GB did work on the 15" 2010, but that 2x8GB didn't.
 

brdeveloper

macrumors 68020
Apr 21, 2010
2,499
162
Brasil
- Actually, no. The 15" and 17" 2010 models only support 8GB. It's the 13" that does 16GB.
If you look at reply #14, you'll see 1x8GB did work on the 15" 2010, but that 2x8GB didn't.
You're right, sorry.

I said it's trivial because I was thinking on the 13" models.