Update:
Tried a few Chromium based browsers Opera, Cent, Slimjet, 7 Star, Yandex, Avant Ultimate and Avant( IE engine).
All the above browsers on my system use a little more RAM than Cyberfox and a bit more CPU.
Why is that because they have many processes with just one tab open
.
Opera has 8 processes with 1 tab open and it's not faster than Cyberfox.
The rest of the browsers have less processes about 4 if i remember correctly
but these browsers are not faster than Cyberfox ( on my system).
In my surprise the Chromium browser that performed better on my system was Cent.
After a while it drops it's RAM usage to Cyberfox level and it's speed is pretty good.
Close to Cent was Slimjet which is one of my favorite browsers.
To compare the browsers i had MT page open and Adguard extension installed the same i have in Cyberfox
so the comparison as much possible the same for all browsers.
About Avant browser.
The Ultimate edition has 3 engines ( IE, Chromium enabled by default and Gecko).
Even if you choose the gecko Firefox engine Chromium still runs in memory
which something i don't want.
Avant the simple edition i really liked it. About 80 MB of RAM and fast for an IE based browser.
Downside of Avant is luck of extensions found in Chromium and Firefox based browsers.
But as i said it's light on system and fast enough
.
After trying these browsers i am thinking of installing Cent a second browser on my system
I hope all of you will find these information's helpful