MacBook Pro Freeze after RAM upgrade

By | 21/08/2011

My MacBook Pro came with 4GB of RAM, and 320GB of disk drive. The ThunderBolt technology is also available on my MacBook Pro. I decided recently to upgrade the RAM so it can run smoother with heavy softwares.

Why upgrade MacBook’s RAM?

The main reason to upgrade is that  4GB RAM is not enough on a MacBook Pro if you run a virtual machine with Windows and want to do an RAM intensive work with your Mac. With a total of 8GB RAM, the MacBook Pro runs very smooth, even when running a virtual machine with 1.5GB RAM allocated to Windows 7.

I upgraded my MacBook Pro (early 2011) RAM from 4GB with 2 new CORSAIR 4GB modules, so a total of 8GB  of RAM. I recommend you upgrade your MacBook to 8GB of RAM to enjoy a lot smoother Mac!

The built-in RAM modules from Apple’s MacBook Pro were 2 HYNIX 2GB modules so a total of 4GB RAM.

WARNING: The tests and procedures in this article are for informative purposes only. Gibni.com and its authors take absolutely no responsibility for the damages, errors and troubles you may cause to your devices. Use at your own risk.

RAM issue or not?

Until now, it happened 3 times:

While using my Mac, the screen froze and horizontal lines appeared on the screen. The only way out is to “hard shutdown” the mac by holding down the power button for 7 seconds. From my IT experience, this relates some times to the Graphical Procession Unit (GPU) and some times to the RAM. So either the Graphics card is buggy or the new CORSAIR RAM modules.

Solving : Mac freeze, horizontal lines…

RAM stress test for Mac:

To test the RAM on the Mac, you should run some stress tests to find if any errors lay in the RAM. Sometimes the RAM behaves good in normal conditions but may throw errors on heavy computation. It is recommended to stress the RAM specially if it is new. One of the best tools is MemTest.

Here’s how to use MemTest on Mac:

( I recommend using MemTest on Single User mode to be able to test more memory as in Single User mode the system occupies very few RAM.)

  1. Restart your Mac and hold “Command + S” to go in Single User mode,
  2. A black screen appears with lots of text and after a few moments you will get a prompt,
  3. Type in : memtest all 4
  4. Wait about 1 hour! Remove the 3 to make it just about 20 minutes, but less reliable…
  5. If everything gets passed, your RAM is probably OK
  6. Else, proceed:
  7. The first thing to do is to put back the own Apple’s RAM and run the stress tests again to see if the issue happens or not.

If the new CORSAIR RAM modules are having errors, I should find out which one is messy. I put only one CORSAIR 4GB RAM on the Mac, leaving the other RAM slot empty. Once I find which one is damaged, I will send it back to where I bought it from (RueDuCommerce.com), so they can change it for me.

CPU and GPU stress test for Mac:

If the problem is not with the RAM, it is probably with the GPU, or the way the GPU deals with the RAM (as it shares the system’s RAM)

Start your Mac normally, and use “smallLux GPU” (a tool I used and recommend it) to stress the GPU:

  1. Download SmallLuxGPU
  2. Install and run it
  3. On the top left side, in the interactive modes section, Select “Instances 130Mil Scene”
  4. Set the resolution to the maximum available,
  5. Select GPU + 4 CPU threads
  6. Hit “Run Interactive Mode”
  7. Wait…

Your Mac will run and run and will heat up. If everything goes fine for about 20 minutes, your GPU is OK, else if you get errors, freeze or horizontal/vertical lines on screen, there is an issue either with your GPU or the way it handles its memory.

If your GPU passes the tests above, BUT you still have freeze/horizontal or vertical lines issues, then the problem might be software or something very complicated which is not in the scope of this article. You should call an Apple Authorized Repair expert in your area.

In case you have an issue with the GPU, RAM, CPU or any hardware on your Mac, call an Apple specialist as soon as possible. Don’t try to open up you Mac because there is nothing you can do.

Some tools for your Mac:

Mac RAM Stress test:

Memory Tester from diglloydTools

MemTest for Mac

Mac CPU stress test:

Simple Terminal: open up 8 terminal windws and enter (no quotes) ‘yes > /dev/null’

MySQL stress Test on Mac

Stress CPU from Folding@Home

CPU / GPU stress test:

SmallLuxGPU

CPU, RAM, Hard drive,… Temperature Monitor for Mac:

TemperatureMonitor

Fan speed Control for Mac:

smcFanControl

Category: Informatique - Computers Mac Tags: , ,

About Gi

I love new technologies and try to use them in my everyday life. Since many years ago, I write about these technologies, and provide solutions to the issues people might get using the new world. I tested and experienced the solutions I provide. I love helping people, and that's why my publications have been free until now.

2 thoughts on “MacBook Pro Freeze after RAM upgrade

  1. Elad

    It’s happend to me too.
    I bought Corsair 8GB DDR3 1333MHz and after few hours of using it my Mac freeze and horiziontal lines appear on the screen.

    I think is Corsair issue with Mac’s.

    Reply
  2. Sebastian

    I’ve had the same issues with my macbook pro.
    Have anyone gotten any confirmation on this being a misfit between mac and corsair?

    Reply

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