Compare · Semiconductor, not standard
GaN vs silicon: same watts, half the brick.
Gallium nitride does not change what comes out of the USB-C port — that is still standard Power Delivery. It changes how the adapter gets there: higher switching frequency, less waste heat, and therefore a body roughly a third the volume at the same wattage.
Spec sheet, side by side
| Metric | Silicon (legacy) | GaN |
|---|---|---|
| Switching frequency | Around 100 kHz | Up to tens of MHz |
| Conversion efficiency | Roughly 87–90% | Roughly 93–95%+ |
| 65W-class volume | About 190 cm³ (Apple's old 61W) | About 65 cm³ |
| Heat at full load | Hot to the touch | Warm |
| Output protocols | PD, PPS — identical | PD, PPS — identical |
| Typical port count | 1 | 2–4 at the same size |
| Best-suited devices | Anything, slowly and bulkily | Anything, especially 45W and up |
Efficiency is the mechanism behind the size. Wasting 5% of 65 watts instead of 12% means far less heat to dissipate, so the case can shrink and the internal spacing can tighten. Full explanation at GaN chargers explained.
Where each one wins
Silicon still wins at the bottom of the range. At 20W a silicon brick is already small, already cheap, and the volume saving from GaN is a few cubic centimetres you will never notice in a bag. Certified budget 20W units are overwhelmingly silicon and there is nothing wrong with that.
GaN wins from 30W upward, and wins harder as wattage climbs. At 65W it is the difference between a laptop brick and a folding cube; at 100W and above, multi-port units are only practical because GaN keeps the thermals in check. It also runs cooler in a crowded power strip, which matters more than most listings admit — see why chargers get hot. Class pages: GaN chargers and 65W adapters.
Verdict: GaN above 30W, silicon is fine below it
Buy GaN for anything 30W and up. On delivered watts the two are identical by definition, so the decision rests on size, heat and ports — and GaN wins all three, decisively, at every wattage where the adapter is big enough to notice. Price per watt now favours GaN too at 45W and above, because the ports you get for the money are higher. The exception: at 20W and below, buy whichever certified unit is cheapest and ignore the material entirely; a silicon 20W cube and a GaN 20W cube charge an iPhone identically and differ by about the thickness of a coin. Related: GaN vs GaN Prime, 45W vs 65W, single vs multi-port.
- 20W
Amazon Basics 20W USB-C
The silicon side, where it still makes sense: cheap, certified, and small enough already.
- Output
- 20W USB-C PD
- Ports
- 1× USB-C
- Certified
- UL listed
- GaN
Anker Nano 30W
Where GaN starts paying: 50% more power than a 20W brick in a smaller folding body.
- Output
- 30W USB-C PD
- Ports
- 1× USB-C
- Tech
- GaN
- 65W
Statik 65W GaN 3-Port
The argument in one product: laptop-class watts, three ports, travel size.
- Output
- 65W total
- Ports
- 2× C, 1× A
- Tech
- GaN
Every head-to-head is indexed at charger comparisons.
FAQ
Is GaN safer than silicon?
Neither material is inherently safer. Safety comes from certification and protection circuitry. GaN's practical benefit is lower operating temperature, which reduces stress on components over years of use.
Do GaN chargers charge faster?
Not by themselves. A 65W GaN adapter and a 65W silicon adapter deliver the same 65W. GaN lets manufacturers offer that wattage in a smaller body and with more ports.
Is a GaN charger worth paying more for at 20W?
Rarely. The size difference at 20W is negligible. Save the GaN premium for 45W and above, where it changes what fits in your bag.