Based on the telemetry analysis from our Firefox 54 Funnelcake experiment, we've decided that we should increase 64-bit Firefox's minimum memory requirement from 1800 MB to strictly greater than 2048 MB. Note that users with exactly 2048 MB should now receive 32-bit Firefox, not 64-bit! In practice, this means 64-bit Firefox's minimum memory requirement will be 3 GB because few users have fractional GB sizes between 2-3 GB. Currently: * users with < 1800 MB receive 32-bit Firefox and * users with >= 1800 MB receive 64-bit Firefox. We'd like to change that so: * users with <= 2048 MB receive 32-bit and * users with > 2048 MB receive 64-bit.

Comment on attachment 8897119 [details] Bug 1390253 - Increase RAM threshold for automatic 64-bit installation. https://reviewboard.mozilla.org/r/168408/#review173672 ::: browser/installer/windows/nsis/stub.nsi:190 (Diff revision 1) > ; Blurb duty cycle > !define BlurbDisplayMS 19500 > !define BlurbBlankMS 500 > > -; Amount of physical memory required for the 64-bit build to be selected. > +; Amount of physical memory required for the 64-bit build to be selected (2 GB). > ; Machines with less RAM than this get the 32-bit build, even with a 64-bit OS. "Machines with less RAM than this" should now be something like "Machines with less RAM than or equal to" since users with exactly 2 GB will receive 32-bit.

Tracking this for 56 since we need a fix to support 64-bit users.

Comment on attachment 8897119 [details] Bug 1390253 - Increase RAM threshold for automatic 64-bit installation. https://reviewboard.mozilla.org/r/168408/#review173692

Pushed by mhowell@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/fe4386054522 Increase RAM threshold for automatic 64-bit installation. r=rstrong

Comment on attachment 8897119 [details] Bug 1390253 - Increase RAM threshold for automatic 64-bit installation. Approval Request Comment [Feature/Bug causing the regression]: N/A [User impact if declined]: Suboptimal performance caused by deploying 64-bit builds to machines that we now understand are not well-suited to them. [Is this code covered by automated tests?]: No [Has the fix been verified in Nightly?]: I've manually spot checked that the RAM threshold still functions. [Needs manual test from QE? If yes, steps to reproduce]: No, the memory threshold feature has already been verified (bug 1366860), this just changes where the threshold is at. [List of other uplifts needed for the feature/fix]: None [Is the change risky?]: No [Why is the change risky/not risky?]: Simple change to the threshold value and equality check, no new logic or functionality. [String changes made/needed]: None

Comment on attachment 8897119 [details] Bug 1390253 - Increase RAM threshold for automatic 64-bit installation. Increase memory requirement for 64-bit installation. Beta56+. Should be in 56.0b4.