15-inch Mid-2015 MacBook Pro Catalina fan noise

Uninstall Sophos by following the developer's instructions. Anti-virus software is not needed on a Mac and usually causes more problems than it solves plus it impacts system performance. If you still have the problem after uninstalling Sophos then run EtreCheck and post the report here using the "Additional Text" icon which looks like a piece of paper.

You can also run the Apple Diagnostics to confirm the cooling system is working properly.

Thanks for the report. You do have some software installed that I'm not familiar with so I don't know if it would cause any problems.

I do see you are using some Lexar proprietary software to manage some type of drive storage. You really should not need any third party proprietary software to manage any drives. External drives should be formatted as GUID partition and MacOS Extended (Journaled). If you need to share an external drive with Windows, then use Disk Utility to erase the drive as GUID partition and exFAT. Of course make sure to temporarily transfer any data on the external drive to another location before erasing the drive.

I've never seen the "macOS Mojave Patcher.app" before.

Make sure the Tuxeara software (is it part of the Lexar software?) is completely up to date. NTFS drivers have been known to cause stability and performance issues with macOS. Personally I would let macOS manage any external drives and uninstall this software.

Are you still having issues after having uninstalled Sophos?

Try running Disk Utility First Aid. I suggest running First Aid on the Container and not just the volume. To see the Container as an item to select you must first click on "View" within Disk Utility and select "Show All Devices". Select the Container in the left pane and run First Aid. Even if First Aid shows everything is "Ok" click on "Show Details" and look through the report to see if there are any unfixed errors listed. If there are, then it will require erasing the whole drive to make a fresh file system after which you can restore from a backup. For some reason Disk Utility will report everything is "Ok" when it really is not Ok.

FYI, check to see if your laptop qualifies for this Battery Recall:

https://support.apple.com/15-inch-macbook-pro-battery-recall

Here is the current list of all the publicly acknowledged free repair programs for various Apple products (some have multiple programs):

https://support.apple.com/service-programs

I'm sorry but you realize that an anonymous person on the internet just told you to uninstall your antivirus software and install a program that isn't offered in the official App Store. This website isn't run by Apple, anyone from the internet can contribute here. CPU temperatures of 130-160F are actually fairly high and your fans are responding accordingly. What I'd be wondering is why your GPU is working so hard. Are you watching a movie or running some other program that might be using the GPU like with a high frame rate or to do calculations of some kind?

I'm not advocating for Sophos or against it, I am not familiar with that program really. However it seems like the anti virus is actively doing a scan (based on the executable name). Is it? If so then using 1.1% of the CPU is more than reasonable. Was Sophos installed before you upgraded your OS? I'm not sure how it would make sense to anyone that a program using such a little amount of resources could be responsible for your high fan speeds. You might get some more insight by looking at the Energy tab on Activity Monitor. Have you tried starting your computer in safe mode to see if you get the same problems? Its possible clearing the NVRAM too might help.

Your computer isn't even really doing much according to the screenshots. It's odd that the GPU is reporting such high temperature but Activity Monitor isn't reporting anything shown with high GPU % or Time.

EndCannabisProhibitionNOW wrote:

I'm sorry but you realize that an anonymous person on the internet just told you to uninstall your antivirus software and install a program that isn't offered in the official App Store. This website isn't run by Apple, anyone from the internet can contribute here.

Always good advice, but if you search these forums you will see contributors much more advanced and knowledgeable than myself suggesting the use of EtreCheck which was written by another advanced forum contributor to help contirbutors assist people on these forums. EtreCheck is available in the App Store (BTW, the App Store doesn't mean the apps are legitimate or absolutely safe). EtreCheck is a stand alone app (at least when downloaded from the website - I assume the App Store version is the same) and doesn't need any installation to work. It just collects a sanitized report of the system so contributors can see the exact hardware and the software that is installed as well as the recent system logs.

I'm not advocating for Sophos or against it, I am not familiar with that program really. However it seems like the anti virus is actively doing a scan (based on the executable name). Is it? If so then using 1.1% of the CPU is more than reasonable. Was Sophos installed before you upgraded your OS? I'm not sure how it would make sense to anyone that a program using such a little amount of resources could be responsible for your high fan speeds. You might get some more insight by looking at the Energy tab on Activity Monitor. Have you tried starting your computer in safe mode to see if you get the same problems? Its possible clearing the NVRAM too might help.

Sophos and other AV apps have been shown to severely impact system performance and cause the Mac to run hot. These forums are full of posts where the users' problems disappeared as soon as the AV software, cleaning apps, and third party security apps have been uninstalled. macOS already has good built-in protections to keep the computer safe as long as the user is careful in permitting apps to run when prompted for their admin password. Basic safe computing practices and the built-in macOS security features are more than sufficient.

Even if Sophos isn't using much resources it is still actively running and checking everything which is running on the system. AV apps are tied into the very core of macOS to do their job and being tied into the core like that will cause problems even when the main AV process is not running at high CPU utilization. This means everything that is running on macOS is having Sophos interfere with its normal operations which can have an unknown impact on other processes.

The quality of anti-virus apps is so horrendous these days that I don't recommend running any of them even on a Windows system. I recommend using Microsoft's own AV solution now for Windows' users. Many formerly reputable AV apps have been caught selling user's personal information and even installing questionable extras on their systems. There is no need to have this crap on macOS where it does more harm than good.

Your computer isn't even really doing much according to the screenshots. It's odd that the GPU is reporting such high temperature but Activity Monitor isn't reporting anything shown with high GPU % or Time.

I agree something doesn't see right here, but Activity Monitor doesn't always show the whole truth. It is possible the heatsink thermal compound has dried out raising the idle CPU temps, but it shouldn't raise them high enough for the fans to run at high speed either.