By Walter Jobs, Technology writer and editor · Published 9 October 2026
Short answer: neither sets your frame rate the way a slow processor does, and both can still cost you performance. A motherboard limits you through link width and through what it lets the processor draw. A power supply almost never reduces frame rate, and when it fails it does something worse than that. Four specific faults are worth checking; the general worry about these two components is mostly misplaced.
The motherboard: three real limits
A card in the wrong slot
One slot on your board is wired directly to the processor at full width. The others are wired to the chipset at a fraction of it. Putting a graphics card into a secondary slot can leave it running at a quarter of the link width it expects, and the card will work, silently, while giving up performance.
The same thing happens without you moving anything. On many boards, fitting a fast storage drive into a particular slot takes lanes away from the graphics slot, dropping it from sixteen lanes to eight. The manual documents this in a table most people never open.
How much it costs: on a high end card at eight lanes of a current generation, very little. On a card with a deliberately narrow interface, which is common in the lower and middle tiers, dropping to four lanes on an older generation bus costs a visible amount, and it costs far more when the card runs short of video memory and starts reaching across that bus.
How to check: your graphics driver control panel reports the current link speed and width. Compare it with what the card expects.
Power delivery that cannot sustain the processor
A board’s voltage regulation feeds the processor. A cheap board paired with a power hungry chip can run out of thermal headroom in that circuitry and reduce the processor’s clocks to protect itself. The result looks exactly like a slower processor, because for the duration it is one.
Symptom: full performance for the first few minutes, then a settled lower level. Like all thermal problems it arrives on a delay, which distinguishes it from every configuration fault.
Who this affects: almost exclusively people running a high core count processor on an entry level board. A mid range chip on a mid range board is not in this territory.
Memory support that holds your kit back
Boards differ in how many memory slots they have and how fast they will run them. A four slot board fully populated often runs slower than the same board with two sticks, and an entry level board may refuse to run a fast kit at its rated profile at all. You then have fast memory running slowly, which is a bottleneck you paid to avoid.
How to check: compare the speed Task Manager reports against what is printed on the sticks.
What a motherboard does not do
An expensive board does not make a game run faster. Two boards with the same chipset, running the same processor at the same clocks with the same memory, produce the same frame rate. What you buy with a better board is connectivity, more robust power delivery for heavy chips, better memory support, and overclocking headroom. None of those is a frame rate feature in themselves.
The chipset generation matters only where it changes something measurable, such as the bus generation feeding your card or your drive. A newer chipset is not inherently quicker in games.
The power supply: it does not lower frame rate, it does something worse
A power supply either delivers what the machine asks for or it does not. There is no mode where it quietly supplies slightly less and you lose frames. That is the key difference between this component and every other one on the list.
When a supply is inadequate, the machine shuts off, reboots, or produces a driver crash in the middle of a demanding scene. Those are failures, not slowdowns.
The transient spike problem
This is the one that catches people with apparently adequate supplies. Modern graphics cards draw brief spikes well above their rated figure, lasting a fraction of a millisecond. A card rated at 320 W can momentarily ask for considerably more. An older supply, or one with aggressive protection circuitry, interprets that spike as a fault and cuts power.
The symptom is distinctive: the machine turns off instantly, with no warning, no blue screen and no error, usually at a moment of sudden visual intensity. It then restarts normally and runs fine for an hour. People chase this as a driver fault for weeks.
The relevant specification is not the wattage number but whether the unit meets the ATX 3.0 or 3.1 standard, which defines how much excess it must tolerate and for how long. A good 750 W unit built to that standard handles a card that an older 850 W unit will trip on. Our PSU calculator sizes a supply from your actual parts rather than from a rule of thumb.
What an oversized supply does not buy you
Fitting a 1200 W unit to a machine that draws 450 W does not improve anything. The machine draws what it draws. A supply running at a very low share of its capacity is also slightly less efficient than one in its comfortable range, so the oversized unit is marginally worse on the electricity bill and identical on frame rate.
Where these rank against the real limits
| Component | Can it limit frame rate? | How often it is the real answer |
|---|---|---|
| Graphics card | Yes, directly | Most of the time, and correctly so |
| Processor | Yes, directly | Often, at high refresh and low resolution |
| Memory configuration | Yes, by starving the processor | More often than people check |
| Motherboard | Indirectly, through link width and power limits | Rarely, and usually from a specific misconfiguration |
| Power supply | No. It fails rather than slows | Never for frame rate, sometimes for stability |
So if your frame rate is lower than you expected, these two components are near the bottom of the list to investigate. Check the gap between your main parts first with the bottleneck calculator, and work through low GPU usage while gaming if the card is sitting idle. Come back here if you have an unexplained shutdown, a card reporting reduced link width, or clocks that fall after ten minutes.
Frequently asked questions
Does a better motherboard increase FPS?
No, not on its own. With the same processor at the same clocks and the same memory speed, two boards produce the same frames. A better board can enable higher memory speeds and sustain a power hungry processor without reducing its clocks, and those produce gains. The board itself is not a performance part.
Does the power supply affect FPS?
Not in any normal situation. A supply delivers the requested power or fails to, and the failure mode is a shutdown or a crash rather than a quieter frame rate. The one grey area is a laptop or small form factor machine with a shared power budget, where the system genuinely does reduce clocks to stay within its total.
Is PCIe 3.0 enough for a modern graphics card?
For most cards at full sixteen lane width, the difference against a newer generation is small. It stops being small in two cases: a card with a narrow interface of eight lanes or fewer, and a card running short of video memory, since memory pressure forces traffic across the bus where bandwidth suddenly matters a great deal.
My PC shuts off during games. Is that the PSU?
An instant shutdown with no error message, especially at a moment of sudden visual load, is the classic signature of a supply tripping its own protection on a transient spike. Before replacing it, confirm temperatures are sane and that the card’s power connectors are fully seated, since a partially seated connector produces the same symptom.
Will adding an M.2 drive slow my graphics card?
On some boards, yes. Certain storage slots share lanes with the graphics slot, so populating one drops the card from sixteen lanes to eight. It is documented in the board manual and it is easy to avoid by choosing a different slot. Whether the drop matters depends on your card, and on most it is a small effect.
The power figures referenced here follow the model behind our PSU calculator rather than measurement of a specific machine. The method is set out on how we calculate this.