[Guide] Disk cache location and size + flags to _test_and_try_ [unsupported, experimental]

A Former User

Notice: switches such as single-process --process-per-site --disable-gpu --in-process-gpu etc are likely to cause problems.

GPU sits more idle than CPU and in most cases GPU pushes render faster than CPU (test GPU here: https://gpu.rocks/ (choose texture mode enabled and then click benchmark))

If you have serious issues with performance check these: i) use stable branch instead of beta/developer, ii) pay attention to amount of extensions but moreso sizes of extensions(!), iii) narrow down subscriptions to block lists on ad blockers and such (seriously 2-5 altogether is very sufficient).

iiii) if some websites crawl you down just close the tab (and clear some cache & restart the browser) but just closing the tab and relaunching the site is sufficient in most cases. Some sites are enormous just tab reset you don't need to wreck the browser to havoc because of not refreshing a tab. Also if your running all kinds of gimmicky widgets'n'stuff. iiiii) in Opera's task manager if you're crawling kill GPU process to refresh it automatically launches back up.

If you really need to use dubious --switches it's a good idea to search the internet for more info per --switch. Bear in mind that many --switches are very experimental and some work only in certain branch and/or platform. --cache-dir-location and --cache-dir-size have been for long and are rather stable.

Some flags might give you good results: #num-raster-threads - test with 2. #gpu-rasterization-msaa-sample-count - test with 2 (fastest). #enable-gpu-rasterization test with enable. Enable to test #enable-service-worker-navigation-preload. #enable-resource-prefetch set to learning. Enable: #enable-quic to test if you benefit from it. There's few more but it's a good idea to spend time googling and searching about these.

Explore opera://net-internals/ and opera://net-internals/#httpCache, also explore opera://gpu/ - these places have good information especially when testing and trying and valuating.

To completely relocate Opera install it as standalone/usb -option in installer to a custom location.
But as cache relocation and size is a common aspiration, here's a step by step walkthrough to relocate cache:

0.5. See this pic first: https://goo.gl/rQe5xZ and then proceed:

Create a shortcut of launcher.exe (Opera must be closed, btw)
move it to desktop if u still didn't (don't pin the shortcut before you've have --switches in place)
right click the shortcut on desktop select properties and focus target field on shortcut tab
On target field you see path to installation folder eg:

"C:\Program Files (x86)\Opera Developer\launcher.exe"

do notice quotation marks, if installation is under C:\Users\user account\appdata... then quotation marks might be missing, anyhow:

staying on *target field add:

--disk-cache-dir=D:\Opera\Cache

behind installation path leaving a space between them, eg. like this:

"C:\Program Files (x86)\Opera Developer\launcher.exe" --disk-cache-dir=D:\Opera\Cache

you might want to prepare the line eg. in Notepad first and then copy paste full line ~ as the field in shortcut properties is sort of narrow and the line gets longer as we move on to set allocated disk space.
Now, on target field, after cache dir location leave a space between this time as well, and add:

--disk-cache-size=10000000

Disk cache size is set in bytes, so "10000000" bytes is (only) 10 megabytes. Set your desired cache size as you set your desired cache dir location.

Now you should have a line for target field that looks similar to this:

"C:\Program Files (x86)\Opera Developer\launcher.exe" --disk-cache-dir=D:\Opera\Cache --disk-cache-size=10000000
Press apply in the shortcut and then OK to close.
Now you can pin the shortcut in the desktop to such as taskbar and/or start menu. If you previously already a had shortcut to Opera somewhere (eg. start menu) that/those shortcuts naturally doesn't have your custom settings. Use your shortcut that you edited on desktop at every location where you want shortcut for Opera. Alternatively you can copy paste the same custom --line to existing shortcuts.

Bonus: It's possible to set custom launch values to registry as well, inorder to avoid Opera being launched by other processes etc. Somewhere in the internet I saw instructions for that, google should find. In registry most likely HKEY_CURRENT_USER...