All Posts by Date or last 15, 30, 90 or 180 days.
also by Lloyd: diglloyd.com photography and WindInMyFace.com
Thank you for purchasing through links and ads on this site.
OWC / MacSales.com...
diglloyd Deal Finder...
Buy other stuff at Amazon.com...
877-865-7002
Today’s Deal Zone Items... Handpicked deals...
$1398 $898
SAVE $500

$140 $100
SAVE $40

$699 $549
SAVE $150

$4499 $2649
SAVE $1850

$1699 $1199
SAVE $500

$5999 $5499
SAVE $500

$181 $141
SAVE $40

$7699 $7199
SAVE $500

$4499 $2649
SAVE $1850

$400 $330
SAVE $70

$4499 $2649
SAVE $1850

$2350 $1950
SAVE $400

$1700 $1300
SAVE $400

$200 $160
SAVE $40

$1997 $897
SAVE $1100

$250 $110
SAVE $140

$1199 $1099
SAVE $100

$3999 $2499
SAVE $1500

$200 $170
SAVE $30

$3999 $2499
SAVE $1500

$1498 $1398
SAVE $100

$2497 $1897
SAVE $600

$748 $598
SAVE $150

$899 $699
SAVE $200

$350 $220
SAVE $130

$150 $100
SAVE $50

$799 $799
SAVE $0

$2799 $2099
SAVE $700

$4500 $3500
SAVE $1000

$1699 $1199
SAVE $500

$6799 $6299
SAVE $500

$249 $249
SAVE $0

$3198 $1798
SAVE $1400

$199 $129
SAVE $70

Upgrade the memory of your 2019 iMac up to 128GB

Apple Kernel Bug? 2015 iMac 5K Runs at 0.8 GHz When Cold, Even with Warm Air Out Rear Vents

Mac wish listall 15" Apple MacBook Pro 2017 modelsMPG gets credit if you buy through those links.
MPG tested a fully-loaded 2017 MacBook Pro with 1TB SSD.
Suggested accessories include the OWC Thunderbolt 3 Dock, the 1TB Envoy Pro EX.

Back in August, I reported on the 2015 MacBook Pro dropping to 0.8 GHz when temperatures rose, making it unusable for any useful work.

It turns out that cold also causes an issue, and this time it looks like a bug that does not go away without shutting down and restarting—rebooting did not fix the problem.

Conditions: 33°F inside of my Mercedes Sprinter photography adventure van, rapidly warming interior to 73°F within about 20 minutes.

Clock speed starts at 0.8 GHz and stays there

The graph below from Intel Power Gadget shows the 2015 iMac 5K running like molasses in a refrigerator, at 0.8 GHz. All four CPU cores are at 100%, but at 0.8GHz. User tasks do run, but very slowly, in slow motion.

Initial ambient temperatures of 33°F might explain this behavior as some self-protective measure, but rebooting twice and with warm air coming out of the back of the iMac and with cabin temperature of 73°F the iMac still ran at 0.8 GHz with no sign of changing behavior.

Not until the iMac was shutdown and rebooted did it run at normal speeds.

The Intel CPU seems unlikely to be responsible, since it was at 33.3°C as shown below. Accordingly, a reasonable theory is yet another Apple macOS kernel bug.

Intel Power Gadget showing 2015 iMac 5K running at 0.8 GHz

When this behavior occurs, kernel task consumes all four real CPU cores.

With 2015 iMac 5K running at 0.8 GHz, kernel task consums all four real CPU core at 100%

Save the tax, we pay you back, instantly!
View all handpicked deals...

Nokia 2.2 TA-1179 32GB Smartphone (Unlocked, Tungsten Black)
$140 $100
SAVE $40

diglloyd.com | Terms of Use | PRIVACY POLICY
Contact | About Lloyd Chambers | Consulting | Photo Tours
Mailing Lists | RSS Feeds | Twitter
Copyright © 2020 diglloyd Inc, all rights reserved.
Display info: __RETINA_INFO_STATUS__