Currently Being ModeratedOct 10, 2012 5:43 AM (in response to craiboski)
I am certain that the RAM is in correctly.
Are you really sure?
Try that slot with old ram - will it work?
Currently Being ModeratedOct 10, 2012 7:09 AM (in response to dmdimon)
Have done this and actually have 1G in the bottom slot and 4G in top slot and the system sees 5GB. I think it has to be the firmware and this version will not work with more than 6GB. Thoughts?
Currently Being ModeratedOct 10, 2012 7:19 AM (in response to craiboski)
there was 3.25 Gb barrier on some 2006-2009 chipset from intel, but 2009 MBP AFAIK based on nForce and have no such problems.
- Currently, OSX Leopard (10.5.x) seems to have trouble accessing above 6GB of physical ram. Further testing is being done, but currently, 6GB is the max that is considered "safe".
Update: This is determined as a Firmware problem, not OS. No matter if you’re using Leopard or Snow Leopard or 64-bit Kernel, it will crash with 8GB unless the models specified above.
read details here:
Currently Being ModeratedOct 10, 2012 7:31 AM (in response to craiboski)
According to Apple the Mid-2009 13" MBP can accept 8 GB of ram. If your MBP is not registering the memory module it can be either the module has not been inserted/seated correctly or there is a fault on the module itself. New modules sometimes take effort to insert. Try switching the two new modules, putting the one in question in the upper slot and the other in the lower slot and see if they work. If the one in question still does not work it is probably defective.
Currently Being ModeratedOct 10, 2012 8:14 AM (in response to dmdimon)
So I have the 2.26 GHZ version and according to this link it appears that 8GB should work? DId I read this right?
What is MB990*?
Currently Being ModeratedOct 10, 2012 8:19 AM (in response to Ralph Landry1)
I have confirmed that both 4GB chips are good through the top slot. Tested one at a time and OSX sees them correctly. Any other suggestions?
Currently Being ModeratedOct 10, 2012 8:24 AM (in response to craiboski)
What is MB990*?
it appears that 8GB should work?
modules can run at the edge of possible timings. If so - slight difference between high and low slot could be enough for one of them not works with memory. Determine your model, read carefully what is written about it, check - is there firmware update for your model. Try other make/model of memory.
Currently Being ModeratedOct 10, 2012 8:29 AM (in response to craiboski)
MB990 is the Model Number, but what is important is the Model Identifier that is used to identify the hardware.
If the modules workindividually in the upper slot, but not in the lower slot, then they are not being seated correctly or there is a fault in the lower slot...if your machine is reading your original modules when both installed then it sounds like the new module is not being seated all the way...are they both going in far enough to indicate seating according to the knowledge base article? Timing is not going to be different between the two connectors.