[MacTUG] Thunderbolt 27" Display and random blackouts with more than 8+ Gigs of RAM

[James McConachie]

I believe that I mentioned this in a previous group discussion. Larry from OWC (Other World Computing) has been able to confirm and postulate a solution.

The use of Low Voltage 1.35V instead of the usual 1.5V RAM seems to be the cure. As referenced here.

https://discussions.apple.com/thread/3340067?start=240&tstart=0


Short answer:


Want to note that this thread has issues being noted with a range of systems beyond just the Apple Mac mini 2012. Issues reported in this thread have included prior Mac mini modesl - factory Ram configs, and including systems (such as Retina MacBook Pro) all memory is factory soldered at that. Issues reported are also not consistent even with the same apparent hardware, OS and EFI(at time of posts) in terms of the extremity of the issue and note too those that have no issues to report at all. Where an issue is present, there is good reason to believe issues being experienced are limited to specific machines and/or the cables and displays in combination use there with. Further - Apple has been well aware of these problems and has been eliminating them over the course with firmware (EFI) and likely within OS level updates as well.

---



For the past two weeks we have been doing heavy, ongoing testing with multiple 2012 Mac minis from our 'fleet' of test systems with the 16GB of OWC 1600MHz Low Power (the 1.35V Apple memory spec vs. the 1.5V typical) in working to replicate any issue.



Testing has been done in compliance with Apple's supported configuration use and with the current Apple OS 10.8.4 and latest EFI updates installed.



ZERO ISSUES encountered. In terms of load - connected displays tested at max available resolutions. Short/Long sleeps, short/long activity durations between sleeps, same for restarts same for shut downs and cold starts. Heavy video loads on both displays and light loads and in between + real world use by product dev team for daily tasks. hundreds of dispaly sleep/shutdown/restart cycles. And again - ZERO Issues.



This testing has been using 1 x Apple Thunderbolt Display connected via the Thunderbolt Port

+

27" Dell Display connected direct to Mac mini HDMI port,

24" LG Display connected direct to Mac mini HDMI port,

and

same 24" LG Display connected via Apple HDMI to DVI adapter via Mac mini HDMI Port.

all tests done at max display resolutions.



We are also flagged to collect any data on a reported issue(none since I replied in this thread) so we can test with exact OS version (although will recommend EFI update if EFI is not to current rev in report), exact displays connected and how connected, etc.



While we could replicate some video glitches with the 2012 Mac minis with the then at the time current OS and EFI we tested prior a few months ago - with all the latest updates available through today, we had zero thus far in a much heavier, and longer test cycle - longer because nothing could be replicated. Also should note - even the issues we had once seen were not to the severity of some have reported here.



If an issue is still being encoutered with a 2012 Mac mini that has the current OS and EFI updates installed along with 16GB of our OWC certified and to Apple spec memory, I really want to hear from you. Like to review the exact hardware involved, OS, etc - but ask that you do confirm no outstanding Apple EFI updates.



Have seen some possibility that in a case using a mini-Display port connected display via the thunderbolt port where a cheap cable can be a core issue. But - this thread isn't about using a mini-Displayport connected display. Also - please note that Apple does not support the use of a mini-dislay port or mini-display port adapted display via a Thunderbolt Display.

http://support.apple.com/kb/HT5219?viewlocale=en_US&locale=en_US#11

**Apple's anchors aren't working right on this page for me.... it's Q&A #20 in the list though**



We are happy to do testing with a specific OS version prior to 10.8.4 and see if issue present with such where 10.8.4 operates correct. Also happy to test use of different display and/or a more specific test parameter as well. And... go as far as to take a system in to replicate in our lab and further confirm it's a system isolated issue testing the same hardware on our other Mac minis to confirm issue doesn't occur with that hardware on them.



If this is like some previous OS/EFI corrected glitches - I'd suspect that with each update to root cause is better and better addressed and issue resolved. Our memory is of the best quality with only top tier, major brand memory devices, and configured to Apple's power and other operating specifications. If anything is 'crutch' that affects this issue in a system that has a glitch still not corrected by Apple's ongoing updates, it is likely the higher power-draw (1.5V vs. the Apple 1.35V) of alternative modules. Until we have a Mac mini in our hands that we can replicate the issue and then test further with, this is speculation, but pretty firm ground on such and it's easier/maginally lower cost for us to build 1.5V - but this doesn't line up with what Apple is using - marginally increases Power use and heat generation - and shouldn't be a necessary bandaid in the first place.



We're still testing and hope to attain a system with the issue still occurring to really get to the core.



As an aside - I have been personally using a Retina with 16BB and it was a major PIA before this year's updates. Multiple connecting and reconnecting and restarts to get hot connected displays to come up. At the present - it's now flawless. never an issue anymore. Plug in and go - and I have three different dispaly setups three different locations I use it between. Again, this issue is definitely one Apple has been in general addressing and appears having done so largely with success achieved.


/James

MFCF
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