It seems that sometimes you have to switch to full Sherlock mode and investigate, find clues and evidence, deduct and hopefully find the solution after the process. This can be exciting, boring and anything in between, but one thing is for sure, it is very time consuming. Few weeks ago one of our rigs started to act weird, and after some investigation we’ve found that one of the RAM modules are almost dead. Great, switched back to the original modules while waiting for the replacement. No problem there, or only minor issues, but we desperately need more RAM now.
Use what we have
I thought, ok, we don’t have 64GB then use only 32GB. That’s definitely more than the basic 16GB, should be enough. As we had more and more Memory low messages in Pro Tools, as soon as I had a little time I grabbed the MacPro out of the rack to change the RAM. Apart from some cabling it is really not a big deal. Open the little padlock sign and lift the outer shell up. Push the RAM holder and it’s immediately comes out from the hidden place so you can grab the modules. I precisely inserted the two modules into slot 1 and 3. Put back the shell, connect the cables and you’re ready to get back to work. Well, in theory at least.
After the boot up our rig started to behave like never before. Even launching Pro Tools caused CPU errors, the meter was constantly gliding from 40% to 100% and to red. I couldn’t open even a single, small session. To be honest I’ve never experienced anything like this. At first I tried to open one of our usual (bigger) sessions, but after a few failures to do so I tried to open really small ones without any success.
I knew the RAM modules are fine because they’d been tested. But how come we experienced only minor if any issues with the stock RAM? I have absolutely no idea. But putting the RAM from slot 1 and 3 to slot 2 and 4 solved the problem. No CPU errors, no outrageous 100% values and sessions open without any errors as before the RAM exchange.
Apple hardware test showed that everything is fine, however it is very obvious that it is far from being fine. Now we try to arrange to send back the MacPro to Apple for some thorough testing to confirm if there’s any problem. I hope they have something more deep than the regular hardware test.
If any of you experienced things like this before, don’t hesitate to write me. Any experience or advice is highly appreciated.