The Phone Got Slower Because The Software Got Bigger

The hardware has not changed, and everything takes longer than it did two years ago. Several unrelated effects are stacking up, and only one of them involves anything wearing out.

Software expands into available hardware

Development targets whatever machines are current, and current machines are always the fastest ones. Improvements in hardware are absorbed by features rather than banked as speed.

Higher resolution assets, richer animations and more capable frameworks all consume the additional capacity, and the result runs at roughly the same speed on newer equipment.

On older equipment the same software runs slower, not because it was deliberately degraded but because the assumptions it was built against moved on without it.

Background work grew faster than foreground

Applications now sync, index, back up, scan, prefetch and report continuously, and all of that competes for processor, memory and storage bandwidth.

Each individual task is small and well behaved. Forty of them running on a schedule are collectively significant, particularly on a device with limited memory.

Memory pressure is the sharpest effect, since a device that cannot keep applications resident has to reload them from storage, which is what makes switching apps feel slow.

A nearly full storage device slows down

Flash storage writes in large blocks and must erase before rewriting, so a nearly full device spends time shuffling existing data to assemble free space.

The effect appears as slower saving, slower installation and stuttering during anything that writes, and it worsens sharply as free capacity approaches zero.

Photographs, video and caches expand steadily, so a device that was comfortable when new can be operating in that condition without the owner having done anything.

Ageing cells force conservative behaviour

Battery capacity and peak current delivery both decline with age, and a cell that cannot supply a sudden demand causes an abrupt shutdown under load.

Systems avoid that by limiting how hard the processor is allowed to work when the cell is weak or cold, which trades peak speed for staying switched on.

Replacing the cell restores much of the performance, which is a genuinely useful thing to know about a device that feels tired rather than broken.

Your expectations moved as well

People compare against current devices in shops and in other people's hands, so the reference point shifts continuously while the device stays where it was.

The gap that opens is partly real and partly a change in what counts as normal, and the two are almost impossible to separate by feel alone.

Which is why a phone that seemed acceptable on Tuesday can feel intolerable on Wednesday, having spent the intervening evening next to a newer one.