Unexpected Reboots

The problem was solved with this procedure ?

The problem was solved with this procedure ?

Same issue (as logged here: Retina iMac Freezing and Restarting and here: Re: iMac (Retina 5K, 27-inch, Late 2015) Randomly Restarts Without Errors) but I forgot to add to the list the number of Kernal Panics I have seen since I purchased the Retina iMac.

Too many. Way too many. They used to be such an ubiquitous feature of OSX in the early years but I cannot remember the last time I saw my screen go grey with the Kernal Panic message prior to this iMac. Since I got it there have been over a dozen I would reckon.

A dozen heart-stopping moments of sheer Panic as I realise that my work is lost.

Thanks to Mike Sombrio's info in the first replay I found the most recent Kernal Panic log:

Anonymous UUID: 7BBA746F-FD61-A6ED-9F8E-689C1811ED17

Thu May 12 15:28:43 2016

*** Panic Report ***

panic(cpu 6 caller 0xffffff8011fce40a): Kernel trap at 0xffffff7f94b0254a, type 14=page fault, registers:

CR0: 0x0000000080010033, CR2: 0x000000000000003a, CR3: 0x00000009fc6070ba, CR4: 0x00000000003627e0

RAX: 0xffffff806d01fa00, RBX: 0x0000000000000002, RCX: 0x0000000000000040, RDX: 0x0000000000000000

RSP: 0xffffff80458d3900, RBP: 0xffffff80458d3920, RSI: 0x0000000000000002, RDI: 0xffffff806d01fa00

R8: 0xffffff8063352400, R9: 0x0000000000000000, R10: 0x0000000000000000, R11: 0x0000000000000002

R12: 0x0000000000000002, R13: 0xffffff806d17f000, R14: 0xffffff806d01fa00, R15: 0xffffff806e11c400

RFL: 0x0000000000010202, RIP: 0xffffff7f94b0254a, CS: 0x0000000000000008, SS: 0x0000000000000010

Fault CR2: 0x000000000000003a, Error code: 0x0000000000000000, Fault CPU: 0x6, PL: 0

Backtrace (CPU 6), Frame : Return Address

0xffffff80458d3590 : 0xffffff8011edab12

0xffffff80458d3610 : 0xffffff8011fce40a

0xffffff80458d37f0 : 0xffffff8011fec273

0xffffff80458d3810 : 0xffffff7f94b0254a

0xffffff80458d3920 : 0xffffff7f94b0110e

0xffffff80458d3950 : 0xffffff7f94b06296

0xffffff80458d3970 : 0xffffff7f94b2c057

0xffffff80458d39b0 : 0xffffff7f94b22f9f

0xffffff80458d3a00 : 0xffffff7f9430c154

0xffffff80458d3a30 : 0xffffff7f94b2bf43

0xffffff80458d3a50 : 0xffffff7f9430c523

0xffffff80458d3a80 : 0xffffff7f94312142

0xffffff80458d3ac0 : 0xffffff7f9430a69d

0xffffff80458d3b50 : 0xffffff80124e1592

0xffffff80458d3b80 : 0xffffff80124e220a

0xffffff80458d3be0 : 0xffffff80124df277

0xffffff80458d3d20 : 0xffffff8011f97cc0

0xffffff80458d3e30 : 0xffffff8011edf283

0xffffff80458d3e60 : 0xffffff8011ec28b8

0xffffff80458d3ea0 : 0xffffff8011ed2665

0xffffff80458d3f10 : 0xffffff8011fb8bda

0xffffff80458d3fb0 : 0xffffff8011feca96

Kernel Extensions in backtrace:

com.apple.iokit.IOAcceleratorFamily2(205.3)[1B6944F0-F0F4-3D26-892C-46EB6C5C743 3]@0xffffff7f94306000->0xffffff7f94371fff

dependency: com.apple.iokit.IOPCIFamily(2.9)[4FE41F9B-2849-322A-BBF8-A94816C003D6]@0xffffff 7f9272c000

dependency: com.apple.iokit.IOGraphicsFamily(2.4.1)[172C2960-EDF5-382D-80A5-C13E97D74880]@0 xffffff7f9328b000

com.apple.AMDRadeonX4000(1.4.2)[51145405-BED6-385A-BC64-FCA5B643B249]@0xffffff7 f94af4000->0xffffff7f9512efff

dependency: com.apple.iokit.IOPCIFamily(2.9)[4FE41F9B-2849-322A-BBF8-A94816C003D6]@0xffffff 7f9272c000

dependency: com.apple.iokit.IOGraphicsFamily(2.4.1)[172C2960-EDF5-382D-80A5-C13E97D74880]@0 xffffff7f9328b000

dependency: com.apple.iokit.IOAcceleratorFamily2(205.3)[1B6944F0-F0F4-3D26-892C-46EB6C5C743 3]@0xffffff7f94306000

BSD process name corresponding to current thread: Google Chrome He

Mac OS version:

15E65

Kernel version:

Darwin Kernel Version 15.4.0: Fri Feb 26 22:08:05 PST 2016; root:xnu-3248.40.184~3/RELEASE_X86_64

Kernel UUID: 4E7B4496-0B81-34E9-97AF-F316103B0839

Kernel slide: 0x0000000011c00000

Kernel text base: 0xffffff8011e00000

__HIB text base: 0xffffff8011d00000

System model name: iMac17,1 (Mac-DB15BD556843C820)

System uptime in nanoseconds: 73649663523926

last loaded kext at 47301204708734: com.apple.driver.AppleXsanScheme 3 (addr 0xffffff7f95b31000, size 32768)

last unloaded kext at 47384004181791: com.apple.driver.AppleXsanScheme 3 (addr 0xffffff7f95b31000, size 32768)

loaded kexts:

com.sophos.kext.sav 9.4.52

com.sophos.nke.swi 9.4.52

com.parallels.kext.vnic 11.2.0 32581

com.parallels.kext.netbridge 11.2.0 32581

com.parallels.kext.hypervisor 11.2.0 32581

com.parallels.kext.usbconnect 11.2.0 32581

com.apple.filesystems.smbfs 3.0.0

com.apple.filesystems.afpfs 11.0

com.apple.nke.asp-tcp 8.0.0

com.apple.driver.AppleTopCaseHIDEventDriver 86

com.apple.driver.AppleHSBluetoothDriver 86

com.apple.driver.AudioAUUC 1.70

com.apple.filesystems.autofs 3.0

com.apple.driver.AGPM 110.21.18

com.apple.driver.ApplePlatformEnabler 2.6.0d0

com.apple.driver.X86PlatformShim 1.0.0

com.apple.driver.AppleOSXWatchdog 1

com.apple.driver.AppleMikeyHIDDriver 124

com.apple.driver.AppleMikeyDriver 274.7

com.apple.driver.AppleHDA 274.7

com.apple.driver.AppleGraphicsDevicePolicy 3.7.7

com.apple.driver.AppleUpstreamUserClient 3.6.1

com.apple.kext.AMDFramebuffer 1.4.2

com.apple.driver.pmtelemetry 1

com.apple.iokit.IOUserEthernet 1.0.1

com.apple.iokit.IOBluetoothSerialManager 4.4.4f4

com.apple.driver.AppleIntelSKLGraphics 10.1.4

com.apple.Dont_Steal_Mac_OS_X 7.0.0

com.apple.driver.AppleHV 1

com.apple.AMDRadeonX4000 1.4.2

com.apple.driver.AppleIntelSlowAdaptiveClocking 4.0.0

com.apple.driver.AppleThunderboltIP 3.0.8

com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport 4.4.4f4

com.apple.driver.AppleIntelPCHPMC 1.1

com.apple.driver.AppleIntelSKLGraphicsFramebuffer 10.1.4

com.apple.driver.AppleSMCLMU 208

com.apple.kext.AMD7000Controller 1.4.2

com.apple.driver.AppleMCCSControl 1.2.13

com.apple.AppleFSCompression.AppleFSCompressionTypeDataless 1.0.0d1

com.apple.AppleFSCompression.AppleFSCompressionTypeZlib 1.0.0

com.apple.BootCache 38

com.apple.driver.AppleSDXC 1.7.0

com.apple.iokit.AppleBCM5701Ethernet 10.2.0

com.apple.driver.AirPort.Brcm4360 1040.1.1a6

com.apple.iokit.IOAHCIBlockStorage 2.8.5

com.apple.driver.AppleAHCIPort 3.1.8

com.apple.driver.AppleACPIButtons 4.0

com.apple.driver.AppleRTC 2.0

com.apple.driver.AppleHPET 1.8

com.apple.driver.AppleSMBIOS 2.1

com.apple.driver.AppleACPIEC 4.0

com.apple.driver.AppleAPIC 1.7

com.apple.nke.applicationfirewall 163

com.apple.security.quarantine 3

com.apple.security.TMSafetyNet 8

com.apple.security.SecureRemotePassword 1.0

com.apple.driver.AppleHIDKeyboard 181

com.apple.driver.AppleMultitouchDriver 304.10.2

com.apple.driver.AppleHIDTransport 5

com.apple.driver.IOBluetoothHIDDriver 4.4.4f4

com.apple.kext.triggers 1.0

com.apple.driver.DspFuncLib 274.7

com.apple.kext.OSvKernDSPLib 525

com.apple.iokit.IOSerialFamily 11

com.apple.iokit.IOSurface 108.2.1

com.apple.driver.CoreCaptureResponder 1

com.apple.iokit.IOSlowAdaptiveClockingFamily 1.0.0

com.apple.driver.AppleGraphicsControl 3.12.6

com.apple.driver.AppleThunderboltEDMSink 4.1.1

com.apple.iokit.IOBluetoothHostControllerUSBTransport 4.4.4f4

com.apple.iokit.IOBluetoothFamily 4.4.4f4

com.apple.driver.AppleHDAController 274.7

com.apple.iokit.IOHDAFamily 274.7

com.apple.iokit.IOAudioFamily 204.3

com.apple.vecLib.kext 1.2.0

com.apple.driver.AppleSMBusPCI 1.0.14d1

com.apple.iokit.IOAcceleratorFamily2 205.3

com.apple.driver.X86PlatformPlugin 1.0.0

com.apple.driver.IOPlatformPluginFamily 6.0.0d7

com.apple.kext.AMDSupport 1.4.2

com.apple.AppleGraphicsDeviceControl 3.12.6

com.apple.iokit.IONDRVSupport 2.4.1

com.apple.driver.AppleSMC 3.1.9

com.apple.driver.AppleSMBusController 1.0.14d1

com.apple.iokit.IOGraphicsFamily 2.4.1

com.apple.iokit.IOSCSIBlockCommandsDevice 3.7.7

com.apple.iokit.IOUSBMassStorageDriver 1.0.0

com.apple.iokit.IOSCSIArchitectureModelFamily 3.7.7

com.apple.driver.usb.IOUSBHostHIDDevice 1.0.1

com.apple.driver.CoreStorage 517.20.1

com.apple.driver.usb.AppleUSBHub 1.0.1

com.apple.driver.usb.cdc 5.0.0

com.apple.driver.usb.networking 5.0.0

com.apple.driver.usb.AppleUSBHostCompositeDevice 1.0.1

com.apple.driver.AppleThunderboltDPOutAdapter 4.1.3

com.apple.driver.AppleThunderboltDPInAdapter 4.1.3

com.apple.driver.AppleThunderboltDPAdapterFamily 4.1.3

com.apple.driver.AppleThunderboltPCIDownAdapter 2.0.2

com.apple.driver.AppleThunderboltNHI 4.0.4

com.apple.iokit.IOThunderboltFamily 6.0.2

com.apple.iokit.IOEthernetAVBController 1.0.3b3

com.apple.iokit.IONVMeFamily 1.2.0

com.apple.iokit.IO80211Family 1110.26

com.apple.driver.mDNSOffloadUserClient 1.0.1b8

com.apple.iokit.IONetworkingFamily 3.2

com.apple.driver.corecapture 1.0.4

com.apple.driver.AppleUSBMergeNub 900.4.1

com.apple.iokit.IOAHCIFamily 2.8.1

com.apple.driver.usb.AppleUSBXHCIPCI 1.0.1

com.apple.driver.usb.AppleUSBXHCI 1.0.1

com.apple.iokit.IOUSBFamily 900.4.1

com.apple.iokit.IOUSBHostFamily 1.0.1

com.apple.driver.AppleUSBHostMergeProperties 1.0.1

com.apple.driver.AppleEFINVRAM 2.0

com.apple.iokit.IOHIDFamily 2.0.0

com.apple.driver.AppleEFIRuntime 2.0

com.apple.iokit.IOSMBusFamily 1.1

com.apple.security.sandbox 300.0

com.apple.kext.AppleMatch 1.0.0d1

com.apple.driver.AppleKeyStore 2

com.apple.driver.AppleMobileFileIntegrity 1.0.5

com.apple.driver.AppleCredentialManager 1.0

com.apple.driver.DiskImages 417.2

com.apple.iokit.IOStorageFamily 2.1

com.apple.iokit.IOReportFamily 31

com.apple.driver.AppleFDEKeyStore 28.30

com.apple.driver.AppleACPIPlatform 4.0

com.apple.iokit.IOPCIFamily 2.9

com.apple.iokit.IOACPIFamily 1.4

com.apple.kec.Libm 1

com.apple.kec.pthread 1

com.apple.kec.corecrypto 1.0

System Profile:

AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0x14A), Broadcom BCM43xx 1.0 (7.21.95.175.1a6)

Bluetooth: Version 4.4.4f4 17685, 3 services, 27 devices, 1 incoming serial ports

Thunderbolt Bus: iMac, Apple Inc., 28.1

Memory Module: BANK 0/DIMM0, 16 GB, DDR3, 1867 MHz, 0x85F7, 0x48363432475534324733313836470000

Memory Module: BANK 0/DIMM1, 4 GB, DDR3, 1867 MHz, 0x802C, 0x384B54463531323634485A2D314739453220

Memory Module: BANK 1/DIMM0, 16 GB, DDR3, 1867 MHz, 0x85F7, 0x48363432475534324733313836470000

Memory Module: BANK 1/DIMM1, 4 GB, DDR3, 1867 MHz, 0x802C, 0x384B54463531323634485A2D314739453220

USB Device: USB 3.0 Bus

USB Device: USB3.0 Hub

USB Device: Expansion Desk

USB Device: Backup+ Desk

USB Device: Bluetooth USB Host Controller

USB Device: FaceTime HD Camera (Built-in)

USB Device: USB2.0 Hub

USB Device: USB 2.0 Hub

USB Device: Microsoft 3-Button Mouse with IntelliEye(TM)

USB Device: MS-20 Controller

Serial ATA Device: APPLE HDD ST1000DM003, 1 TB

Model: iMac17,1, BootROM IM171.0105.B07, 4 processors, Intel Core i7, 4 GHz, 40 GB, SMC 2.33f10

Network Service: Ethernet, Ethernet, en0

Network Service: Wi-Fi, AirPort, en1

Graphics: AMD Radeon R9 M390, AMD Radeon R9 M390, PCIe, 2048 MB

I wish I understood any of the above.

My suspicions definitely lie with an some issue with the Retina graphics card. The screen refresh can be seriously buggy at times. Being honest, and this is a just my observation, adding 2x16GB RAM modules to the 2x4GB ones the iMac came with has had virtually no noticeable effect to the performance of the mac. It struggles with a load of chrome tabs open, plus some Creative Suite apps, Parallels 11 and a Windows10 environment just as much as with the original 8GB (and my late 2012 27 iMac with 32GB RAM was able to perform so smoothly with the exact same requirements). It almost seems like the system RAM requirements are being dumped into the Graphics Card, hence the glitches, stutters, screen redraw artefacts, freezes and crashes. I know that is probably technically impossible but it sure seems like how it's behaving.

I wish there was some way of consolidating all the different threads that are highlighting the same thing - the fact that there is a serious flaw in these Late 2015 retina iMacs. There are so many now.

Just noticed in that panic report that the backtrace references "com.apple.AMDRadeonX4000" but the actual graphics card is AMD Radeon R9 M390.

I have no idea if that is relevant. But it does look like a discrepancy.

It looks like your graphics card is failing but there are a few things you need to eliminate before you make an appointment for service. Apple is going to insist on these anyway so we'd might as well get them out of the way. First you need to uninstall Sophos, the panic started when your iMac saw Sophos and it's been known to cause problems anyway so uninstall it. Next remove the third party ram. If the panics persist see if you can post another panic log. If the panics stop then you can try adding the ram back in and testing.

Hi Mike,

Many thanks for your response. I dunno how you understand these logs. Are there any walk-throughs or "idiot guides" to these logs and what they mean? 🙂

These random reboots and kernal panics all happened before I purchased the 3rd party RAM and I had hoped that the issue was the default 8GB was too little for the basic tools of a graphic designer on a mac - Photoshop, Illustrator, Chrome, Suitcase, Office, iTunes and Mail... y'know, the basics!

Here is today's panic log, if you can discern a pattern. I was messing around within Ableton Live (quite a few crashes happen within Ableton which makes me think the audio card and graphics cards or something between them is banjaxed) when this happened:

Anonymous UUID: 7BBA746F-FD61-A6ED-9F8E-689C1811ED17

Wed Jun 8 20:07:01 2016

*** Panic Report ***

panic(cpu 4 caller 0xffffff8003fce5fa): Kernel trap at 0xffffff7f86b0440e, type 14=page fault, registers:

CR0: 0x0000000080010033, CR2: 0x000000000000003a, CR3: 0x00000005fdb1815a, CR4: 0x00000000003627e0

RAX: 0xffffff80744b5a00, RBX: 0x0000000000000002, RCX: 0x0000000000000040, RDX: 0x0000000000000000

RSP: 0xffffff8490413800, RBP: 0xffffff8490413820, RSI: 0x0000000000000002, RDI: 0xffffff80744b5a00

R8: 0xffffff8054add800, R9: 0x0000000000000001, R10: 0x00000000000013c0, R11: 0x0000000000800001

R12: 0x0000000000000002, R13: 0xffffff8052250000, R14: 0xffffff80744b5a00, R15: 0xffffff806cff8400

RFL: 0x0000000000010202, RIP: 0xffffff7f86b0440e, CS: 0x0000000000000008, SS: 0x0000000000000010

Fault CR2: 0x000000000000003a, Error code: 0x0000000000000000, Fault CPU: 0x4, PL: 0

Backtrace (CPU 4), Frame : Return Address

0xffffff8490413490 : 0xffffff8003edab12

0xffffff8490413510 : 0xffffff8003fce5fa

0xffffff84904136f0 : 0xffffff8003fec463

0xffffff8490413710 : 0xffffff7f86b0440e

0xffffff8490413820 : 0xffffff7f86b02fd2

0xffffff8490413850 : 0xffffff7f86b0815a

0xffffff8490413870 : 0xffffff7f86b2df3f

0xffffff84904138b0 : 0xffffff7f86b25a91

0xffffff8490413a00 : 0xffffff7f8630e020

0xffffff8490413a30 : 0xffffff7f86b2de2b

0xffffff8490413a50 : 0xffffff7f8630e3ef

0xffffff8490413a80 : 0xffffff7f8631406e

0xffffff8490413ac0 : 0xffffff7f8630c5fe

0xffffff8490413b50 : 0xffffff80044e1d22

0xffffff8490413b80 : 0xffffff80044e299a

0xffffff8490413be0 : 0xffffff80044dfa07

0xffffff8490413d20 : 0xffffff8003f97eb0

0xffffff8490413e30 : 0xffffff8003edf283

0xffffff8490413e60 : 0xffffff8003ec28b8

0xffffff8490413ea0 : 0xffffff8003ed2665

0xffffff8490413f10 : 0xffffff8003fb8dca

0xffffff8490413fb0 : 0xffffff8003fecc86

Kernel Extensions in backtrace:

com.apple.iokit.IOAcceleratorFamily2(205.10)[949D9C27-0635-3EE4-B836-373871BC62 47]@0xffffff7f86308000->0xffffff7f86373fff

dependency: com.apple.iokit.IOPCIFamily(2.9)[D8216D61-5209-3B0C-866D-7D8B3C5F33FF]@0xffffff 7f8472c000

dependency: com.apple.iokit.IOGraphicsFamily(2.4.1)[172C2960-EDF5-382D-80A5-C13E97D74880]@0 xffffff7f8528d000

com.apple.AMDRadeonX4000(1.4.2)[EB770DE1-7B50-364F-9198-AE65399F5D67]@0xffffff7 f86af6000->0xffffff7f87130fff

dependency: com.apple.iokit.IOPCIFamily(2.9)[D8216D61-5209-3B0C-866D-7D8B3C5F33FF]@0xffffff 7f8472c000

dependency: com.apple.iokit.IOGraphicsFamily(2.4.1)[172C2960-EDF5-382D-80A5-C13E97D74880]@0 xffffff7f8528d000

dependency: com.apple.iokit.IOAcceleratorFamily2(205.10)[949D9C27-0635-3EE4-B836-373871BC62 47]@0xffffff7f86308000

BSD process name corresponding to current thread: Live

Mac OS version:

15F34

Kernel version:

Darwin Kernel Version 15.5.0: Tue Apr 19 18:36:36 PDT 2016; root:xnu-3248.50.21~8/RELEASE_X86_64

Kernel UUID: 7E7B0822-D2DE-3B39-A7A5-77B40A668BC6

Kernel slide: 0x0000000003c00000

Kernel text base: 0xffffff8003e00000

__HIB text base: 0xffffff8003d00000

System model name: iMac17,1 (Mac-DB15BD556843C820)

System uptime in nanoseconds: 45119717590294

last loaded kext at 42606349110392: com.apple.driver.AppleTopCaseHIDEventDriver 86 (addr 0xffffff7f87b89000, size 57344)

last unloaded kext at 41207878770643: com.apple.driver.IOBluetoothHIDDriver 4.4.5f3 (addr 0xffffff7f8544a000, size 73728)

loaded kexts:

com.parallels.kext.vnic 11.2.0 32581

com.parallels.kext.netbridge 11.2.0 32581

com.parallels.kext.hypervisor 11.2.0 32581

com.parallels.kext.usbconnect 11.2.0 32581

com.apple.driver.AppleTopCaseHIDEventDriver 86

com.apple.driver.AppleHSBluetoothDriver 86

com.apple.filesystems.smbfs 3.0.1

com.apple.filesystems.afpfs 11.0

com.apple.nke.asp-tcp 8.0.0

com.apple.driver.AudioAUUC 1.70

com.apple.driver.AGPM 110.22.0

com.apple.driver.ApplePlatformEnabler 2.6.0d0

com.apple.driver.X86PlatformShim 1.0.0

com.apple.filesystems.autofs 3.0

com.apple.driver.AppleOSXWatchdog 1

com.apple.driver.AppleMikeyHIDDriver 124

com.apple.driver.AppleMikeyDriver 274.9

com.apple.driver.AppleHDA 274.9

com.apple.driver.AppleGraphicsDevicePolicy 3.12.7

com.apple.driver.AppleUpstreamUserClient 3.6.1

com.apple.kext.AMDFramebuffer 1.4.2

com.apple.driver.pmtelemetry 1

com.apple.iokit.IOUserEthernet 1.0.1

com.apple.iokit.IOBluetoothSerialManager 4.4.5f3

com.apple.AMDRadeonX4000 1.4.2

com.apple.Dont_Steal_Mac_OS_X 7.0.0

com.apple.driver.AppleIntelSKLGraphics 10.1.4

com.apple.driver.AppleThunderboltIP 3.0.8

com.apple.driver.AppleHV 1

com.apple.iokit.BroadcomBluetoothHostControllerUSBTransport 4.4.5f3

com.apple.driver.AppleIntelPCHPMC 1.1

com.apple.driver.AppleSMCLMU 208

com.apple.kext.AMD7000Controller 1.4.2

com.apple.driver.AppleIntelSlowAdaptiveClocking 4.0.0

com.apple.driver.AppleIntelSKLGraphicsFramebuffer 10.1.4

com.apple.driver.AppleMCCSControl 1.2.13

com.apple.driver.AppleUSBStorageCoexistentDriver 3.7.1

com.apple.AppleFSCompression.AppleFSCompressionTypeDataless 1.0.0d1

com.apple.AppleFSCompression.AppleFSCompressionTypeZlib 1.0.0

com.apple.BootCache 38

com.apple.iokit.IOAHCIBlockStorage 2.8.5

com.apple.driver.AppleSDXC 1.7.0

com.apple.iokit.AppleBCM5701Ethernet 10.2.0

com.apple.driver.AirPort.Brcm4360 1040.1.1a6

com.apple.driver.AppleAHCIPort 3.1.8

com.apple.driver.AppleACPIButtons 4.0

com.apple.driver.AppleRTC 2.0

com.apple.driver.AppleHPET 1.8

com.apple.driver.AppleSMBIOS 2.1

com.apple.driver.AppleACPIEC 4.0

com.apple.driver.AppleAPIC 1.7

com.apple.nke.applicationfirewall 163

com.apple.security.quarantine 3

com.apple.security.TMSafetyNet 8

com.apple.driver.AppleMultitouchDriver 304.12

com.apple.driver.AppleHIDTransport 5

com.apple.driver.IOBluetoothHIDDriver 4.4.5f3

com.apple.security.SecureRemotePassword 1.0

com.apple.driver.AppleHIDKeyboard 181

com.apple.kext.triggers 1.0

com.apple.driver.DspFuncLib 274.9

com.apple.kext.OSvKernDSPLib 525

com.apple.iokit.IOSerialFamily 11

com.apple.iokit.IOSurface 108.2.1

com.apple.driver.CoreCaptureResponder 1

com.apple.iokit.IOBluetoothHostControllerUSBTransport 4.4.5f3

com.apple.iokit.IOBluetoothFamily 4.4.5f3

com.apple.driver.AppleHDAController 274.9

com.apple.iokit.IOHDAFamily 274.9

com.apple.iokit.IOAudioFamily 204.4

com.apple.vecLib.kext 1.2.0

com.apple.driver.AppleGraphicsControl 3.12.8

com.apple.iokit.IONDRVSupport 2.4.1

com.apple.driver.AppleSMBusPCI 1.0.14d1

com.apple.driver.AppleThunderboltEDMSink 4.1.1

com.apple.kext.AMDSupport 1.4.2

com.apple.driver.X86PlatformPlugin 1.0.0

com.apple.driver.IOPlatformPluginFamily 6.0.0d7

com.apple.iokit.IOSlowAdaptiveClockingFamily 1.0.0

com.apple.AppleGraphicsDeviceControl 3.12.8

com.apple.iokit.IOAcceleratorFamily2 205.10

com.apple.driver.AppleSMC 3.1.9

com.apple.driver.AppleSMBusController 1.0.14d1

com.apple.iokit.IOGraphicsFamily 2.4.1

com.apple.iokit.IOSCSIBlockCommandsDevice 3.7.7

com.apple.iokit.IOUSBMassStorageClass 4.0.2

com.apple.iokit.IOUSBMassStorageDriver 1.0.0

com.apple.iokit.IOSCSIArchitectureModelFamily 3.7.7

com.apple.driver.usb.IOUSBHostHIDDevice 1.0.1

com.apple.driver.usb.cdc 5.0.0

com.apple.driver.usb.networking 5.0.0

com.apple.driver.usb.AppleUSBHostCompositeDevice 1.0.1

com.apple.driver.CoreStorage 517.50.1

com.apple.driver.usb.AppleUSBHub 1.0.1

com.apple.driver.AppleThunderboltDPInAdapter 4.1.3

com.apple.driver.AppleThunderboltDPOutAdapter 4.1.3

com.apple.driver.AppleThunderboltDPAdapterFamily 4.1.3

com.apple.driver.AppleThunderboltPCIDownAdapter 2.0.2

com.apple.driver.AppleThunderboltNHI 4.0.4

com.apple.iokit.IOThunderboltFamily 6.0.2

com.apple.iokit.IOEthernetAVBController 1.0.3b3

com.apple.iokit.IO80211Family 1110.26

com.apple.driver.mDNSOffloadUserClient 1.0.1b8

com.apple.iokit.IONetworkingFamily 3.2

com.apple.driver.corecapture 1.0.4

com.apple.iokit.IONVMeFamily 1.2.0

com.apple.driver.AppleUSBMergeNub 900.4.1

com.apple.iokit.IOAHCIFamily 2.8.1

com.apple.driver.usb.AppleUSBXHCIPCI 1.0.1

com.apple.driver.usb.AppleUSBXHCI 1.0.1

com.apple.iokit.IOUSBFamily 900.4.1

com.apple.iokit.IOUSBHostFamily 1.0.1

com.apple.driver.AppleUSBHostMergeProperties 1.0.1

com.apple.driver.AppleEFINVRAM 2.0

com.apple.iokit.IOHIDFamily 2.0.0

com.apple.driver.AppleEFIRuntime 2.0

com.apple.iokit.IOSMBusFamily 1.1

com.apple.security.sandbox 300.0

com.apple.kext.AppleMatch 1.0.0d1

com.apple.driver.AppleKeyStore 2

com.apple.driver.AppleMobileFileIntegrity 1.0.5

com.apple.driver.AppleCredentialManager 1.0

com.apple.driver.DiskImages 417.4

com.apple.iokit.IOStorageFamily 2.1

com.apple.iokit.IOReportFamily 31

com.apple.driver.AppleFDEKeyStore 28.30

com.apple.driver.AppleACPIPlatform 4.0

com.apple.iokit.IOPCIFamily 2.9

com.apple.iokit.IOACPIFamily 1.4

com.apple.kec.Libm 1

com.apple.kec.pthread 1

com.apple.kec.corecrypto 1.0

Apologies for the data dump and the brain drain. It's just great (and heartbreaking) to see others experiencing the same issues with this particular model. I would love to know how many Late 2015 27" iMacs have been returned/replaced as compared to other models over the same space of time.

May i know if there is any problem after the logic board and memory replacement?