I used to be a display architect about 15 years back (for Qualcomm mirasol, et al), so my knowledge of the specifics / numbers is outdated. Sharing what I know.

High pixel density displays have disproportionately higher display refresh power (not just proportional to the total number of pixels as the column lines capacitances need to be driven again for writing each row of pixels). This was an important concern as high pixel densities were coming along.

Display needs fast refreshing not just because pixel would lose charge, but because the a refresh can be visible or result in flicker. Some pixels tech require flipping polarity on each refresh but the curves are not exactly symmetric between polarities, and further, this can vary across the panel. A fast enough refresh hides the mismatch.

There's definitely a few reasons but one of them is that you have to ask the GPU to do ~60x less work when you render 60x less frames

This is an OLED display, so I don't think the control electronics are actually any less active. (They would be for LCD, which is where most of these low-refresh-rate optimizations make sense.)

The connection between the GPU and the display has been run length encoded (or better) since forever, since that reduces the amount of energy used to send the next frame to the display controller. Maybe by "1Hz" they mean they also only send diffs between frames? That'd be a bigger win than "1Hz" for most use cases.

But, to answer your question, the light emission and computation of the frames (which can be skipped for idle screen regions, regardless of frame rate) should dwarf the transmission cost of sending the frame from the GPU to the panel.

The more I think about this, the less sense it makes. (The next step in my analysis would involve computing the wattage requirements of the CPU, GPU and light emission, then comparing that to the KWh of the laptop battery + advertised battery life.

I think the idea is that in an always-on display mode, most of the screen is black and the rest is dim, so circuitry power budget becomes a much larger fraction of overhead.

I interpreted that bit as E2E system uptime being up by 48%. Sounds more plausible to me, as there'd fewer video frames that would need to be produced and pushed out.

Before OLED (and similar), most displays were lit with LEDs (behind or around the screen, through a diffuser, then through liquid crystals) which was indeed the dominant power draw... like 90% or so!

But the article is about an OLED display, so the pixels themselves are emitting light.