Why do Android phone manufacturers describe RAM in powers of 1,000 but not 1,024 (as PCs do)?

tl:dr: Android memory is more in line with hard disk memory and uses the SI or decimal standards unlike PC memory. Standards support this

Basing my answer on What is the advantage to using a factor of 1024 instead of 1000 for disk size units? - Software Engineering Stack Exchange and bringing out only the key aspects. Details can be referred in that question

• In the case of PC's, quoting from the accepted answer binary addressing was adopted

It is kind of convenience and optimization for getting the most usable, addressable space between the two considerations of addressing and physical platter size

• For Disk drives SI units were adopted. From Bobson's answer

The disk drive industry followed a different pattern. Industry practice, more thoroughly documented at Timeline of binary prefixes
and continuing today, is to specify hard drives using SI prefixes and symbols in their SI or "decimal" interpretation. Unlike binary-addressed computer main memory, there is nothing in a disk drive that influences it to have a total capacity easily expressed using a power of 1024.

(Emphasis Supplied)

That explains in brief the reasons for binary and SI

Evolution of Mobile Phones and Standards

• The earliest commercial model phone DynaTAC 8000Xappeared on the scene in 1983. It couldn't do anything more than basic calls so RAM doesn't come into play




• By 1987 hard drives were marked in SI units as can be seen from the binary timeline linked




• Feature Phones: IBM Simon was the first feature phone in 1994, which had 1 MB of RAM and 1MB of storage expandable to 2 MB - you read that right :) So, when the feature phone cane out , SI standards were in vogue

So, likely reasons :

• SI standards were automatically applied to mobile memory as they were more viewed as storage elements rather than computational requirements




• Fact that memory was / is not based on platters (see accepted answer ) , adopting binary system made no sense . Instead of having separate nomenclature for storage and RAM, SI units were adopted for both. But in the case of PC's legacy continued, though one could argue that it is incorrect. Mac OS since
  has since version 10.6 (Mountain Lion in 2011) shown hard drive size using decimal prefixes and continues to do so




• By 1998

IEC introduces unambiguous prefixes for binary multiples (KiB, MiB, GiB etc.), reserving kB, MB, GB and so on for their decimal sense

• By 2001 Linux Kernel (used in Android) adopted IEC standards