This Is How Much Of Your System’s Resources Flash Can Use Up

This Is How Much Of Your System’s Resources Flash Can Use Up

We already know that enabling Flash in the browser can impact your computer’s performance and, along with other factors, slow browsing to a crawl. PCWorld did some tests to find out just how much of a difference running Flash makes.

In a word: significant. With both Microsoft Edge and Opera, having Flash enabled consumed over 80% of the test computer’s CPU cycles, compared to 33% and 7%, respectively, without Flash. Flash also consumed a significant amount of memory with both browsers.

Firefox’s benchmarks weren’t so dramatic, but the experience was the same:

Firefox? Well, Firefox did swimmingly as well, when you removed Flash from the equation. It consumed 1.65 GB, and needed only 24.5 per cent of the CPU. But after I downloaded Flash, Firefox seemed to throttle itself. The browser never climbed above 29.1 per cent of the CPU, but some tabs were unresponsive minutes after loading, and I had to manually check each tab to check on its progress. That was totally unacceptable.

There are no comparison numbers for Chrome in this article, which notes that with Flash enabled Chrome consumed 4.23 GB of memory and 71.4% of the CPU, so better than Microsoft Edge. PCWorld senior editor Mark Hachman tells me, however, that there is a difference for Chrome with Flash disabled, but those numbers will be revealed in an upcoming browser roundup they’re doing. In the meantime, you can test for yourself by going to chrome://plugins and disabling Flash.

To do this test, PCWorld used a Lenovo Yoga 12 notebook with an Intel Core i7 processor, Windows 10 Pro (64-bit), and 8 GB of memory. They loaded 30 sites in separate tabs, then recorded the CPU load and memory consumption — for the latest versions of the browsers with and without Flash installed or enabled.

YMMV. Some sites aren’t functional without Flash, your computer might have better or worse specs than this test system, and you might not be a 30-tabs at a time kind of browser user. But if you need any more reasons to uninstall or disable Flash (besides privacy issues and frequent security vulnerabilities), this might be another big one.

As an alternative, you can use your browser’s click-to-run option for Flash to only enable it when necessary.

Tested: How Flash destroys your browser’s performance [PCWorld]


  • That’s a really stupid scale for the CPU%. Should have had a second scale on the other side. The above looks insignificant until you read the article.

  • Flash doesn’t cause issues on my machine. Keep in mind that the current trend of cramming too much javascript into websites causes more problems than poorly coded or misused Flash. What next? Kill javascript because too many idiots insist on motion scroll effects and onBlur marketing pop-ups just because you mouse hovers over another browser tab?

    If you don’t like browser plugins in general, that’s one thing. But have the guts at least to condemn all browser plugins, not just Flash – which is actually a powerful suite of tools capable of far more than HTML5. Sure, HTML5 has replaced the need for Flash for a lot of things found on a web page, except the one thing Flash is good at… complex games and polished full screen applications, which obviously will use the CPU more than text and a few images on a web page. If you’re using a horrible bunch of JS frameworks to achieve complex results in the browser, good luck with optimising everything from runtime performance to loading efficiency cross browser. iOS Safari even on an iPad suffers from poor memory – it can’t even keep a medium size web page in memory when switching between tabs, the whole page needs to load again. Apple has no interest in allowing the browser to perform to the level of native apps. It doesn’t take a genius to work out why.

    Sure, “requiring a plugin” is not ideal, but Flash is suited to special content for which HTML simply can’t match – both in output and in the tools used to build it.

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