How to overcome JS lags in Opera 12.16?

Question

Opera

Good afternoon. There is Opera/9.80 (X11; Linux x86_64) Presto/2.12.388 Version/12.16.

When browsing sites vk.com (mostly chat), youtube.com, tumblr.com, Opera starts to slow down. CPU usage (opera:cpu) on this tab is up to 99%.

From correspondence with VK support, I learned the following: Opera 12 has an allegedly buggy JS engine that "cannot cope with a large amount of JS on the site." Previously, I have not met claims against JS in Opera and the accusation from VK looks both doubtful (this Opera gave up on us?) And plausible (Opera was not ready for tons of JQuery on sites?).

For example - Sun Spider gives 70-80% of the download and does not cause the browser to freeze.

I would like to get a reasonable answer - do the listed portals demonstrate the inability (unwillingness) to write fast JS code or is it in the Opera engine?

Please refrain from answers in the spirit of "put chrome (fox, ...)".

Answer 1

So what's the salt? Indeed, in performance. But not the JS engine , which had a fairly good reputation . VK support also drew attention to JS garbage collection, there are supposedly memory leaks in its mechanism. But the GC doesn't make obvious mistakes either.
In the benchmark suggested by @HeadOnFire there is a JS/DOM performance test , where Opera comes second to last. I think this is the reason for the slowdown in cases where the page is created dynamically using JS, JQuery and similar technologies. In my opinion, frequent re-creation and modification of the DOM structure is largely unjustified, but that's another topic.
Thanks to all.

Answer 2

Opera 12 has a rather weak js engine, and since this is far from the top version, it is quite logical that VKontakte developers ignore it. Since version 15+ (I don't remember exactly) opera is based on the blink core, which is essentially a chrome core. Since the share of Opera is small, and current versions have relatively complete support for everything that is in chrome. no one pays much attention to the support of this browser.
As for youtube, etc., the audience of Opera users for these sites is negligible and the developers have never officially supported these browsers. Vadim Makeev in the report even once told how they, through familiar developers, made their own fixes so that something would work under opera (they provided the fixes themselves, already ready).

Answer 3

If you do not want to change the browser, then use at least the latest version of it ...

Answer 4

The 12th opera has a dead engine, that's a fact. The version is far from fresh, no one is going to support it, no one needs it. VK support gave a very clear and correct answer. @Fesor covered it further, and @Nc_Soft gave some really good advice. Update your browser and don't fool yourself or people.
More about Opera performance:
www.tomshardware.com/reviews/chrome-27-firefox-21-...