Safe Mode Boot vs. Recovery Mode specifications

Question

Safe Mode Boot vs. Recovery Mode specifications

Can someone please direct me to a detailed list (specification) of exactly what is disabled during a Mac OS Safe Mode Boot (Power-Shift key) vs. Recovery Mode (Power-CMD-R)?

My Mac developed either HW or SW issues and only boots without fatality in Safe Mode. I cannot find a detailed list to understand the problem better, but narrowed it down to either the GPU (accelerated graphics disabled during Safe Mode) or a corrupt startup SW issue (startup items disabled during Safe Mode). I have never dealt with the case of not being able to run Recovery Mode or boot up to another boot drive (Power-OPT, where I also get failure). Sounds crazy that it runs fine with no failure in Safe Mode if it has failing HW, even a GPU. I would have thought Recovery Mode would also disable the same items, but I cannot find Apple specs on these Modes!

MacBook Pro 17" running 10.12.6, has the NVIDIA GeForce GT 330M graphics card

Failure includes random black screen followed by spontaneous restarts. Only runs in Safe Mode.

MacBook Pro 17″, macOS 10.12

Posted on Jan 22, 2021 3:35 PM

Reply

Answer 1

Best reply

HWTech

Level 9

55,550 points

Jan 22, 2021 6:38 PM in response to susannefromboise

You don't mention what happens when you boot into Recovery/Internet Recovery Mode, but I suspect you may have a bad GPU which is very common with the 15" & 17" models. Booting into Safe Mode disables the discrete GPU driver for the NVidia GPU.

You can force the laptop to use the Intel GPU by running gfxCardStatus.

Safe Mode disables some Apple drivers and all third party drivers, startup items and login items. Safe Mode also runs a file system check and deletes some temp & cache files. Recovery Mode boots with a limited macOS framework and minimal utilities. The link for Safe Mode is all I know. I'm not aware of any specific articles with under the hood details about Recovery Mode except for what I've personally experienced and mentioned here.

If gfxCardStatus doesn't help, then run EtreCheck and post the report here using the "Additional Text" icon which looks like a piece of paper.

Reply

Answer 2

Jan 23, 2021 3:48 PM in response to HWTech

Thanks again, attached is the Etrecheck text report. I played with gfxCardStatus and it appears it isn't possible for me to force it to use only Integrated Only. It always switches to Dynamic Switching. Under Dynamic Switching both graphics processors can be called. I verified this by opening Affinity Photo, which requires High Perf (Discrete) and it ran, and the gfxCardStatus switched to d from i, with Dynamic Switching still checked. Activity Monitor says High Perf graphics (NVIDIA) are running. No crashes. Switches back to i when the app is closed and then Activity Monitor reports only the Integrated Intel graphics is running. I can't find documentation so I reported this as an issue on the gfxCardStatus GitHub page, asking for clarification on how this code works. Unfortunately this only confuses me on what the root cause is of my black screen-restart issues. Forcing a true disable of the GPU in firmware sounds good but I noticed it comes at a cost: brightness and sleep functions are affected. Also, the fix is for an AMD chip on a 2011 MBP, would it apply to an NVIDIA on a 2010 MBP?

EtreCheck report

Reply

Answer 3

Jan 24, 2021 3:47 PM in response to HWTech

Thanks again. I was able to run Disk Utility and DriveDx in Normal mode, attached the latter report; Disk Utility had no errors whatsoever. I replaced the original drive about 3 years ago, so it shouldn't be failing and I didn't see anything problematic, but you are probably better at reading/interpreting these reports.

I did play with gfxCardStatus some more and found the scant documentation on it on the developer site (not GitHub). He sort of makes it clear that this app is not meant to disable bad discrete GPU HW, that it is more for battery management and a tool to see which apps are running High Perf graphics. It surprised me how many apps do. In fact, I've had a (brief) screen flash issue for almost 2 years that I correlated with the switch between Integrated and Discrete graphics from the top right menu status icon switching between i and d. This app gives a better indicator of this switching than the Activity Monitor. Forcing a machine to use Integrated Only isn't really a solution, since one will get a window saying which apps won't run properly without Dynamic Switching, which is probably why it boots automatically to Dynamic Switching after setting it to Integrated Only. So at best, it's an informational tool. Trying to run Affinity Photo in Safe Mode is impossible -- it absolutely requires the discrete GPU.

Looking for an HDMI cable so I can run the external monitor tests and SMC/PRAM resets, but these are good tests and who knows, may fix an issue with power management that is causing this mess. I ran multiple SMC/PRAM resets using the native keyboard before I posted this support issue but maybe an external keyboard might be best to rerun them.

I'll keep the NVRAM fix as a last resort after I open the machine up and clean it out (and to check all the cable connections, clean out the fan/ventilation). I still think it could be a thermal issue due to the random black screen crashes-hangs-restarts. Am I getting ready for its funeral? You bet! But I still think this was a quality product given 10 years of heavy use for a high-perf laptop. I'm not seeing Apple make anything better lately and there will be new issues with the Apple native HW!

DriveDx report

Reply

Answer 4

Jan 23, 2021 10:12 AM in response to HWTech

Thanks HWTech for responding. I already tried gfxCardStatus a few days ago, installed it in Safe Mode and set it to automatically start up with only the Integrated Intel graphics checked (no Discrete). It didn't work, got a random black screen/restart fail on Normal boot. I also tried unchecking Automatic Graphics Switching under Energy Saver, didn't help.

I ran EtreCheck in Safe Mode, no major HW issues but I am running the free version without the power user report. Before completely crashing on Normal startup, I was able to run a hard disk check with Disk Utility and got no issues. Could it be a startup item (SW) that isn't loaded in Safe mode but loaded in all other modes? Didn't see anything in the EtreCheck report that was a problem, and I haven't installed anything recently new. I don't think the Adobe Flash or Microsoft Update launchers that were part of installations years ago could be the problem, but some say remove them anyway. The report does say that I have kernel extensions that may not work in the future. Since I can't boot up in recovery or normal mode to upgrade the OS, not sure what the fix is for that, or if kernel panics are an eventual result. It took 10 years to get a black screen-reset issue as described.

I've spent a few hours reading over what others have done to fix the NVIDIA GPU issue with associate black screen crashes, which may not be a failing chip per se. Seems there are several who were able to modify the AppleGraphicsPowerManagement.kext file, several who replaced the bad tantalum capacitor that supplies voltage to the chip and several who just cleaned and replaced the thermal paste on the board. Since I've already changed the hard drive on this machine myself a few years ago it may be worth trying just opening it up again, cleaning it out, replacing thermal paste, looking for loose connections. The problem with the .kext fix is that it was done for a 15" not a 17" which has different power management specs.

By the way, the 17" MacBook Pro is the best Apple ever made IMHO. Worth saving and reusing. Jobs was still alive when this was manufactured in 2010! Took 10 years of heavy use to fail.

Reply

Answer 5

Jan 23, 2021 10:33 AM in response to HWTech

Added to below: I again tried gfxCardStatus that I installed already a few days ago and booted this time into Verbose Mode (Power-CMD-V). It didn't crash as usual. However the setting now is back to Dynamic Switching in the app. Is this a bug? I intentionally set it to Integrated Only in Safe Mode, shut down and Power-CMD-V and when it loaded the icon in the top menu bar is i not d and the setting checked to Dynamic Switching (!) Bug? How can I tell if only the Integrated Graphics is working and not Discrete (NVIDIA chip disabled)????

Reply

Answer 6

HWTech

Level 9

55,550 points

Jan 23, 2021 12:58 PM in response to susannefromboise

You do not need to pay for the EtreCheck power usage report if you post the EtreCheck report here other contributors will analyze it for you. Post the report here using the "Additional Text" icon which looks like a piece of paper.

The GPU issue of these 15" & 17" models is not usually caused by thermal paste issues, but by cracked solder joints. Some GPU failures can be caused by a weak or defective capacitor as well (or so I've heard).

I know the gfxCardStatus page mentions the slightly different issues between various models of Apple laptops for these GPU failures. I've never investigated to understand how gfxCardStatus is forcing the laptop to use the Intel GPU. I do know there is another option to configure a setting within the NVRAM by using the information in this article (keep in mind a PRAM Reset will remove the modified settings):

http://dosdude1.com/gpudisable/

I cannot address your other questions since I've never really managed those settings and am not sure how they behave.

Reply

Answer 7

HWTech

Level 9

55,550 points

Jan 23, 2021 7:06 PM in response to susannefromboise

I don't see anything of concern in the report except you should uninstall Adobe Flash once you get the laptop working again since Adobe Flash has been discontinued by Adobe. Leaving Flash installed is a security risk since no legitimate website should be using or requiring Flash.

Make sure your Wacom & XQuartz software is up to date. These are probably the most likely items which would be causing a problem booting normally since Safe Mode works, but any of the software items listed in the report which are listed as "Not Loaded" could be the problem since it means they are not running in Safe Mode, but are likely running (aka loaded) in normal mode.

While the drive speed appears Ok in the EtreCheck report I would suggest running DriveDx and posting the report here using the "Additional Text" icon which looks like a piece of paper. It also would not hurt to run Disk Utility First Aid on the hidden Container. Within Disk Utility click on "View" and select "Show All Devices" so that the Container appears on the left pane of Disk Utility. Even if First Aid reports everything as "Ok" click "Show Details" and look for any unfixed errors or warnings. If there are unfixed errors, then you will need to erase the whole physical drive and restore from a backup or clone.

Just about every 15" or 17" MacBook Pro from 2007/8 to at least 2015 has GPU issues to one extent or another (most common and widespread are on 2008, 2010, and 2011 plus some 2013 models affecting both AMD & NVidia GPUs). If by "Forcing a true disable of the GPU in firmware" means the DosDude's method of modifying the NVRAM then it works for both AMD & NVidia GPUs because the NVRAM setting is a system wide pre-boot configuration setting. It is not a permanent modification since a PRAM reset will destroy the custom settings and revert the NVRAM settings to system defaults.

I guess another good question is whether you have the same video issue when using an external display. I assume you will, but it is worth verifying. Maybe the problem is with your built-in display. In order to boot normally you will need to put the laptop into Clamshell mode by closing the lid of the laptop (immediately after powering on the laptop) to force all video to go to the external display (you will need an external keyboard & mouse). This is the only way to see anything on the external display before or while macOS boots. You may want to perform a PRAM Reset as well using an external USB keyboard while the laptop is in Clamshell mode if you don't see anything on the external display.

Reply

Answer 8

HWTech

Level 9

55,550 points

Jan 25, 2021 9:23 AM in response to susannefromboise

The "Load Cycle Count" (attribute #193) is beyond the manufacturer's expectations. Since this attribute is considered a "Life-span" item it doesn't mean the drive actually is bad at this point. However, in my personal experience when I see this attribute go beyond its end of life maximum I tend to see the drive begin to slow down and even have weird intermittent issues. Normally I like to repurpose older drives for test systems & diagnostics, but most drives with the Load Cycle Count beyond maximum and otherwise healthy still won't work reliably enough even for such purposes. It seems this hard drive has just recently exceeded its maximum value.

FYI, the high Load Cycle Count is due to more recent versions of macOS aggressively sleeping and waking the drive. Recent versions macOS are notorious for killing otherwise healthy hard drives in this manner. Attribute #191 "G-Sense Error Rate" is also beyond what the manufacturer considers acceptable. This attribute indicates that the hard drive has experienced physical shocks during its operation.

The drive also reports seven Command Timeouts which may possibly be related to the high Load Cycle Count or the G-Sense Errors". Also I find most 2.5" hard drives installed in laptops are lucky to get 5K hours on them because they experience bumps/jolts from use in a laptop. Your drive has almost 7,500 hours on the drive. Even if this 2.5" hard drive was installed in a Mac Mini many times I see 2.5" hard drives only last for 15K hours although I have seen a few go up to 20K or 30K hours in a Mac Mini.

Personally I would replace this hard drive as I now consider it unreliable.

Reply

Safe Mode Boot vs. Recovery Mode specifications

Similar questions