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Re: Turning off win64 builds

Gregory Szorc Nov 22, 2012 1:01 PM
Posted in group:
On 11/21/12 8:19 AM, Benjamin Smedberg wrote:
> On 11/16/2012 1:11 PM, Benjamin Smedberg wrote:
>> For these reasons, I would like to propose that we disable the 64-bit
>> Windows nightly builds. We should publish a custom update to move
>> current win64 nightly users back onto win32.
> Thank you to everyone who participated in this thread. Given the
> existing information, I have decided to proceed with disabling windows
> 64-bit nightly and hourly builds. Please let us consider this discussion
> closed unless there is critical new information which needs to be
> presented.

For those running into the 32 bit memory ceiling, you have a legitimate
complaint: your usage pattern of Firefox may no longer be supported by
32 bit builds. I don't like it when someone forces me to change either,
so I sympathize with you.

Many of the people hitting this memory ceiling are hitting it because
they have many tabs open - possibly hundreds of tabs. There are a number
of things that can be done to abate this.

The obvious solution: don't have so many tabs open! May I suggest using
some form of bookmarking or read it later instead. There are numerous
add-ons available if the features in Firefox itself aren't satisfactory.

Another solution is to restart your browser periodically. Firefox 13
introduced on-demand tab loading. So, when you restart your browser,
tabs aren't loaded until you actually use them. The relevant preference
in about:config is browser.sessionstore.restore_on_demand. It's "true"
by default. Be sure you haven't accidentally changed it to false.

These are two things tab-heavy users can do today to control memory
usage. Unfortunately, they both require a change in browsing behavior.
This is not ideal.

In bug 675539 (, we
are tracking a feature to automatically unload unused tabs, freeing
memory in the process. Once this lands, this should (finally) keep the
memory footprint of Firefox in check for tab-heavy users.

Now, not all encounters with the memory ceiling are due to large numbers
of tabs. Generally speaking, if you get Firefox to use 1GB+ of memory
with only 3 or 4 tabs open, you are dealing with a) something suboptimal
in Firefox itself b) a leaky or wasteful add-on or plugin c) a
sub-optimally designed web site d) a web site that truly needs massive
amounts of resources. Arguably the only scenario that's OK there is "d."
And, these web sites are currently few and far between. As they become
more prevalent, I'm sure Mozilla will revisit the 64 bit decision and/or
a per-process browser model because not doing so would be to the
detriment of the web.

Anyway, if you encounter extreme memory usage with only a few open tabs,
please file a bug at By doing so, you are
telling the people who have the greatest chance of fixing it.