I have a three year old Motorola phone that has gone rather suddenly from working fine to stuttering badly on many simple actions. I thought the problem was caused by running out of memory, but looking at the “memory use” report (accessible when “developer options” is turned on) shows that memory (RAM) is only half used, so that’s not it.

What else would cause a phone to slow down drastically? It’s a bit of a puzzle. I tried running the CPDT storage performance report app. An interesting result! Writing to the internal flash storage is very slow, less than 10 megabytes per second, slower than the benchmark result for any other similarly aged device. There’s plenty of flash space available, but it’s very slow. There are periods of several seconds where almost no data is being written.

Why would old flash memory be slow? I’m not exactly sure, but I think it’s to do with allocation. Flash memory uses blocks and can only write a whole block of data at a time. Parts of a block that are no longer in use can be reused by consolidating unused space, but that requires effective communication between the operating system and the flash controller hardware about data that’s no longer in use. If the flash controller doesn’t have a clear picture of what data the operating system has discarded it gets busy finding space to move data from partially used blocks whenever it has to write new data.

What to do? I backed up my data and factory reset the phone. Ta-da! CPDT now reports a five times improvement in sequential flash write speed (50 megabytes per second) and the long pauses are gone. The phone is now quite usable and I don’t have to replace it. Great!

But, my goodness, getting all my apps working again … sigh. The Android backup/restore managed to install most of the apps and some of the configuration automatically, but it’s very incomplete.

I had a dozen or so web pages open in Firefox, but that data wasn’t sync’d, so those are gone. I remembered to save the Nova launcher config so I didn’t have to rebuild the launcher pages. I copied my eBooks off to Google Drive. I have to login again with every other app attached to a service (social media, messaging, readers, recommender apps, music, tv, etc., etc.), dozens of apps in total.

I have three multi-factor authentication apps needed for various high security accounts (Google Authenticator, Duo Mobile and Symantec VIP Access). Each one had a different account recovery process. I don’t think I’m locked out of anything I care about, but … sheesh.

The biggest pain was backing up and restoring Signal. You need to manually save and restore the data file and then hand copy and type a thirty digit security code. For real. It may have great security, but this app’s usability is terrible for people who want to keep their contacts and messages across phones (i.e. everyone). I’ll have to write another post about messaging apps.