Ad Block Plus uses more memory and slows computer more than ads

Adblock Plus (ABP), which is by far the most popular add-on for Firefox and Chrome, is actually increasing the amount of memory used by your web browser, rather than decreasing it. Furthermore, ABP also increases the amount of time (and CPU cycles) required to render a website. Instead of making web surfing more responsive, ABP actually makes your surfing experience slower.

ABP’s initial popularity stemmed from its ability to block noisy, annoying, and resource-hogging Flash ads. Now, because ABP’s block list is so large, it probably consumes more RAM and CPU cycles than it saves (though it will vary from site to site, of course).

Mozilla developer Nicholas Nethercote explains the memory effect of Adblock Plus

Other options for getting rid of video ads are Privoxy, Flashblock or Noscript.

Of course Nextbigfuture is a free site that has an interest in ad revenue. If there is a complaint about an advertiser that is using video ads, then we block those annoying ads.

Memory Usage

1. There’s a constant overhead just from enabling ABP of something like 60–70 MiB. (This is on 64-bit builds; on 32-bit builds the number is probably a bit smaller.) This appears to be mostly due to additional JavaScript memory usage, though there’s also some due to extra layout memory.

2. there’s an overhead of about 4 MiB per iframe, which is mostly due to ABP injecting a giant stylesheet into every iframe. Many pages have multiple iframes, so this can add up quickly. For example, if you load TechCrunch and roll over the social buttons on every story (thus triggering the loading of lots of extra JS code), without ABP, Firefox uses about 194 MiB of physical memory. With ABP, that number more than doubles, to 417 MiB. This is despite the fact that ABP prevents some page elements (ads!) from being loaded.

A Chrome developer confirmed the memory issue exists with Chrome as well.

Chrome see the Adblock memory usage (and much more) as well.

Adblock, noscript, ghostery, and other addons like them cause 90% of the issues Chrome sees in the forums.

At the very least, by running any of these you are:
* Increasing memory usage anywhere from 10% to 30%
* increasing overall cpu usage across all cores
* increasing overall load time of the page by about 15% to 50%

completely screwing many of the optimizations that have gone into the browser, effectively making the multi-threaded nature of the browser fight itself.

This is because these programs need to interrupt any and all http calls to check them against a big list of “no-no” domains held in memory. If it matches, they remove the element from the dom so it doesn’t load and let the browser continue.
This has the effect of making every single thread sync up each time the dom is updated, so these extensions can scan the new elements to ensure they aren’t loading ads/scripts. Fancy stuff like threaded compositing, network predictors and prefetchers, and batched layout rendering are all abandoned when any one of these is in play.”

SOURCES – Mozilla, Extreme Tech, Reddit