I also have older sony vaio laptop with sandybridge and I've solved my tearing in Firefox with hardware acceleration enabled because Firefox hardware acceleration is disabled by default.
In address bar type about:config and search "layers.acceleration.force-enabled" and just double click it so the value is "true". In "preferences" in Firefox under performance I've unchecked "Use recommended performance settings"...just in case, and leave "Hardware acceleration" checked 🙂. And also in 20-intel.conf file I only have Tearfree option and that even solved my problem with gnome mpv when client side decorations are "on"
I am using Gnome version of Solus.
Hope this will help you.

    MTech It could totally be a solution for Firefox. But it is not for Telegram and Thunderbird apps for example. That problem is so awful. :/

    Anyways, thanks you Mtech.

        alan-g59 No problem. It's a common problem on all linux disrtibutions because of xorg. Maybe you can try Fedora because Fedora is using Wayland by default.

            MTech I did not have that problem when I was a Linux Mint Cinnamon user.

            And fact is Budgie desktop is not available with Fedora.

            I felt in love with Solus because of Budgie. Also, because Solus is very light (only 2GB ram is required), not like Ubuntu Budgie.

            Overmore, because Solus updates all his softwares, including Libreoffice. This is not the case of Linux Mint. To have recent versions of softwares, you have to use flatpack or snap. (Worst of all, Linux Mint could totally prohibite Snap in the future to protect apt.)

            Finally, I love Solus because this OS is easier than a Fedora distro or a Manjaro distro.

            So yes, switching to other OS is not the solution. The solution could be configuring this to fix this. How ? That's the question. 😭

              alan-g59 Preferences -> Advanced -> Config Editor
              Then it's pretty much the same as in Firefox, just keep in mind that Thunderbird engine is always a few versions behind the Firefox one so settings that have been added in the recent versions of Firefox won't work.

                  May be the compositor is having issue..recently i tried i3 WM with compton and firefox started screen tearing ....Same machine with Budgie there is no screen tearing...Anyone have knowledge about Budgie compositor (changing compositor settings) can give a try and let us know plz.

                    kyrios I added this to Thunderbird. Thanks. But Telegram still does this to me… 🙁

                    viyoriya If you think the problem is due to the Solus compositor, well… Maybe.

                    What compositor uses Linux Mint Cinnamon ?

                        viyoriya We just pushed an update of compton today, previous update was in April so between first half of April and this afternoon it wasn't touched.

                          8 days later

                          alan-g59 really i stopped using firefox and didn't notice screen tearing have you found anything ?

                              viyoriya No. That's why I'm asking.

                              I think, otherwise, I will migrate to Ubuntu Budgie… :/

                                  alan-g59 just try to find out what causing the issue...what if something happen in Ubuntu Budgie then you switch over to other distro ?...🙂 its absolutely your decision

                                    Firefox Screen tearing not happening in startx...if i use lightdm it starts again..anyone know whats the difference between startx and lightdm..if anyone using other DM can let us know the tearing issue.

                                    7 days later

                                    Ok, after a vacation, I'm back. I have to say that tutorial pretty worked for me : https://learnubuntumate.weebly.com/screen-tearing-on-intel-graphics.html#

                                    sudo gedit /etc/X11/xorg.conf.d/20-intel.conf :

                                    Section "Device"
   Identifier "Intel Graphics"
   Driver "intel"
   Option "AccelMethod" "uxa"
   Option "TearFree" "true"
   Option  "TripleBuffer" "true"
EndSection

                                    The tearing problems are now only on Gnome MPV, in full screen.

                                    I don't have tearing problem anymore in Telegram, in Firefox, in Vivaldi, in MPV and in VLC. Only on Gnome MPV. Maybe there is something with Gnome MPV. I don't understand but whatever.

                                    I know. In the Arch wiki, they said that Option "TearFree" "true" is not compatible with Option "AccelMethod" "uxa" but "sna". I have to say maybe for the majority of CPUs but not mine. Mine is very particular. We're speaking about a Sandy Bridge CPU, you know. 😉