Power-supply planning
The least interesting component in the machine, and the one whose failure can take other parts with it.
Where the budget goes first
Sufficient capacity with headroom
Sized to peak draw plus margin, not to a minimum figure.
The right connectors
Capacity is irrelevant if the cable the card needs is absent.
Quality
This is the component whose failure is least likely to be contained.
Room for what comes next
The next graphics card will not draw less.
The symptoms look like software
An overloaded power supply does not usually announce itself either. It shows up as shutdowns under load, restarts during games or renders, and instability that appears only when the machine is working hard.
Because those look exactly like a driver or operating-system fault, people reinstall, replace drivers and lose days before the supply is suspected. It is worth ruling out early.
Size for peaks, not averages
Graphics cards in particular draw in short spikes well above their stated figures. A supply chosen against the average is a supply that will occasionally be asked for more than it has, and the result is a machine that shuts down without explanation.
Headroom also means the unit is not running at its limit continuously, which is where efficiency and lifespan both suffer.
- Total capacity with genuine margin above expected peak
- The specific connectors the graphics card requires
- Enough capacity for the upgrade you already anticipate
The one component not to economise on
Most components fail alone. A power supply can fail in ways that damage what it was powering. That asymmetry is the argument for buying a good one — it is not about performance, because a power supply has none.
What each choice costs elsewhere
| Choice | What it buys | What it costs |
|---|---|---|
| Higher capacity | Headroom now and for the next card | Slightly more, for no performance gain today |
| Modular cabling | Cleaner build and better airflow | A small premium |
Questions
How large a power supply do I need?
Can a failing power supply damage other parts?
Next
Graphics card upgrades
Cooling and thermal planning
PC components
Size it against your parts
Send us the component list and we will calculate what the supply needs to be.