Memory Upgrade Crashes VM

Hello,

I am running an iMAC OS X 10.8.2 build 12C60. I recently upgraded to parallels desktop 8 for MAC, build 8.0.18354.

I wanted to upgrade the RAM on m iMAC from 4GB to 8GB, and everything is fine on MAC side until I launch parallels, which then crashes my machine.

I've talked to parallels support several times who at this point has not called me during the scheduled window they are telling me they will call, and they call after hours or late on weekends. I now I just learned they closed my ticket.

The last message they left was for me to call Apple, which is ridiculous because the memory works fine with the iMAc, but crashes only when I launch parallels.

Things the support team had me try before they closed my ticket, create a new virtual machine, then using the old hard drive. This did not work. I then tried to create a brand new VM, this does not work either.

This is the last response I received ( and by the way, jt hasn't been 14 days and they closed ticket anyway):

Hello Bill,

Thank you for your response and appreciate your patience in troubleshooting this issue.

As we understand that you are facing an issue with the Virtual Machine as it crashes the Mac as soon as it launches with the new RAM installed in Mac.However, when the old RAM installed everything works fine.

Since, the issue is related on changing hardware of the Mac, we recommend you to contact Apple for further assistance as they will be able to assist you better.

This ticket will be placed in a Pending confirmation by customer status. Bill, you can reply to this email within 14 days and the ticket will be reopened automatically. After 14 days the ticket will be placed in a closed status and can not be re-opened. Please feel free to contact us for any further assistance.


If anyone can help it would be greatly appreciated.

 

The memory does not necessarily work fine on the Mac, in fact it doesn't at all, Parallels is a OSX application, what happens is that Parallels uses quite a big chunk of memory and as such it is likely encountering a defect present in the new RAM module, unfortunately this may indeed happen on a newly purchased module. This will also likely happen if you fill up all the RAM on the Mac (dozens of browser tabs and windows, Photoshop, etc, etc).

What you need to do is test the memory via hardware diagnosis, like memtest or Apple own hardware diagnosis tools: http://support.apple.com/kb/HT1883

This is also what Apple will recommend you to do and what any technician should recommend. In fact this should be the first thing anyone should do when they upgrade their RAM and any technician worth they salt should know that (this is a direct reference to Parallels Support). The importance of this is to catch defects early while the RAM warranty is still valid and to be sure any future problem is not related to this.

 

Thank you. I will test this first thing in morning and post my results. I finally did speak to someone else today at parallels support who wants me to move the .pvm to an external drive, delete the application and reinstall.

Also, when I launch parallels, no other programs are open on Mac side. It crashes most times when I click on the application, sometimes I get as far as entering my username and password. But the entire Mac crashes.

My only question is why does the Mac behave normally until I open parallels? If it doesn't work at all, how does it function until parallels is in the mix?

And no one has even suggested testing the ram besides you so I appreciate the advice.

 

And I did speak to memory ten support, where I purchased the ram and they confirm the ram is correct for my machine. They had me test machine with 1 stick at time and its fine as long as parallels isn't running. The only way parallels works is with old ram.

 

A couple of facts:

* It's not the case the memory not being adequate for your machine, I'm sure it is, it is a question of having just one sector, or maybe more, but one is enough (yes, this is just like hard drives, except RAM has no way get around it and isolate the sector) in the whole module defective, unfortunately, it does happen, the result being, when something is written to that defective sector the data stored then becomes corrupt when reading back and it crashes.

* Why does it happen when you run Parallels? Simply because Parallels by booting a VM is likely the application in your mac that uses most RAM, if you have 4 GB RAM assigned to the VM it will consume all that and use all that memory space, so it's more likely to encounter the bad sector in your new module if there is one than any other program on your Mac, that's the reason. If you had any other program that could consume as much RAM, say Photoshop opening very very large images you would likely encounter a crash also.

Defective RAM modules is something that, unfortunately, is not uncommon. Hence my recommendation, which I know you don't hear a lot, that whenever someone buys RAM they should test it immediately, it's a bit time consuming, and normally doesn't show up any errors, but you'll know from that moment on your RAM can be trusted.

As for the people that sold you the RAM, they certainly aren't interested in taking back the module they sold and giving you a new one, unless you can prove via hardware test that the memory is defective.

I'm not saying the module is defective, but the symptoms are the same if it was defective, so you should clear that up right up front.

By the way, when doing hardware diagnosis if it asks for Short(Basic) or Long("Perform extended testing"), first do a short one and if no errors are found, do a long one, it will take about an hour or even two(yep, that's why few people do this) but it will test every single byte in all modules.

A good walk-thru of Apple Hardware Test: http://reviews.cnet.com/8301-13727_...nvoke-and-interpret-the-apple-hardware-tests/

By the way, if it wasn't clear yet, I'm calling every single technician you contacted about this problem an *d*ot for not making you test your RAM via Apple Hardware Test or Memtest86.

 

Well you were right. The quick test ran from DVD showed the following:

4mem/9/40000000: 0xb8acc98

And at this point with all the waiting and bs tests asked from parallels support team, I am probably outside the return window for these modules.

 

I'm really sorry to hear that, but I was 99% sure that was the case, the symptoms were obvious for a techie. Yes Parallels support should have seen the obvious.

But I also blame the memory guys that told you to try with and without the RAM module, the fact that it worked without the RAM module was obvious enough that something was wrong with the module AND not with Parallels, I think they deliberately and knowingly tried to put the blame on Parallels app just so they didn't have to return it.

Anyway, it's still under warranty I'm sure.

Good luck with returning the module, glad I could help in some way.

 

Specimen,

Just a quick update, received new memory, immediately tested it and it passed all. Everything is now fine. Thanks for your help!

 

Good to hear.
Happy computing!