Often, yes, with an important caveat about which method you use. Published community results show a well-tuned RTX 5090 undervolt cutting power by about 13–18% for 0–2% lower frame rates. Simply lowering the power limit costs more: ComputerBase measured about 5% lower performance at 450 W and about 10% at 400 W, against 575 W stock. Either way, efficiency improves sharply, because the last 100 W or so buys very little speed. Every card is different, though. An undervolt that's stable in one game can crash another, so test carefully and keep expectations modest.
What do the published results show?
| Setting (source) | Power | Performance | Frames per watt vs stock |
|---|---|---|---|
| Stock, Space Marine 2 (Tech Yes City) | 575 W | 133 fps | Baseline |
| 2.7 GHz at 960 mV (Tech Yes City) | 485 W (−16%) | 133 fps (0%) | +19% |
| 2.5 GHz at 900 mV (Tech Yes City) | 405 W (−30%) | 125 fps (−6%) | +33% |
| 2.3 GHz at 875 mV (Tech Yes City) | 356 W (−38%) | 117 fps (−12%) | +42% |
| Power target 450 W, 19 games at 4K (ComputerBase) | −22% | Just over 5% slower | About +21% |
| Power target 400 W, 19 games at 4K (ComputerBase) | −30% | About 10% slower | About +29% |
| About 895 mV at about 2,800 MHz (r/nvidia, via GameGPU) | −13 to −18% | 0–2% slower | Not stated |
Source: Tech Yes City, single game, relayed via r/hardware (23 Jan 2025); ComputerBase via WinFuture (26 Jan 2025); GameGPU (31 Oct 2026) citing an r/nvidia thread. Frames-per-watt figures are our arithmetic. The Tech Yes City and r/nvidia results are single-card community results, not lab averages.
Two things stand out. First, a curve undervolt (lower voltage at a given clock) beats a plain power limit at the same wattage, because the card keeps its clocks instead of throttling. Second, the 5090 is less forgiving than the 4090. ComputerBase found the 4090 lost just under 2% going from 450 W to 350 W, while the 5090 lost just over 5% going from 575 W to 450 W. Even so, the 5090 at 400 W was still about 12% faster than a stock 4090.
What's the difference between undervolting and a power limit?
- Power limit: a slider in the driver or a tool such as MSI Afterburner that caps board power. It's simple, can be reversed instantly and is very unlikely to cause instability. The card reaches the cap by lowering clocks, so you lose some performance.
- Curve undervolt: you edit the voltage–frequency curve so the card runs a chosen clock at lower voltage. Done well, it holds near-stock clocks at much lower power. Done badly, it causes crashes, driver resets or rare visual errors. It needs testing across your actual games and apps.
A sensible approach is to start with a power limit around 450–500 W. Then, if you want more, try a modest undervolt and test it in your most demanding titles, a long render and an overnight AI job before relying on it.
The RTX 5090 spends its last 100 watts buying very little speed. Taking them back is the easiest efficiency gain on the card.
Does it work for AI and rendering too?
Yes, and the pattern is informative. One community test (Zenn, 29 Aug 2026, Palit 5090 GameRock, CUDA 13) compared 575 W with a 400 W limit:
- Single-user LLM token generation in llama.cpp fell about 5% (75.9 to 71.9 tok/s); SGLang at one concurrent user was unchanged at about 226 tok/s.
- Prompt processing fell about 8%, and serving 128 concurrent users about 4.5%.
- Fine-tuning fell about 11%, other training jobs 7–9%, and SDXL image generation about 9%.
- Energy per job fell 21–23% for compute-heavy runs, and peak draw dropped from 686 W to 495 W.
That fits how these workloads behave. Generating text for one user is limited by memory bandwidth, which a power limit barely touches. Training, batched serving and image generation are limited by compute, so they slow more. The author recommended 400 W for always-on inference and 400–450 W for training. For more on what limits AI speed, see why AI developers still complain about 32 GB.
How much money does it save in Singapore?
At SP Group's Q4 2026 tariff of 31.16¢ per kWh including GST:
- Gaming: saving 90 W for four hours a day is about 131 kWh a year, or about S$41.
- Always-on AI: running at 400 W instead of 575 W saves 175 W, which is about 1,533 kWh, or about S$478 a year at full load around the clock.
These are illustrative upper bounds: real gaming draw is often 460–550 W rather than 575 W, and the tariff resets each quarter. The heat saving is just as useful. Every 100 W removed is about 341 BTU/h less heat in your room. Our 575 W power post has full running-cost figures.
Is it safe, and does it affect the warranty?
- Stability: results depend on your individual chip. A setting that passes one benchmark may fail in another game. If you see crashes, raise the voltage a step or return to stock.
- Temperatures: at 400 W, the Zenn test saw the hotspot fall from 91 °C to 77 °C and the fan from 52% to 38%. Memory temperature barely changed, at about 71–73 °C.
- Warranty: we found no NVIDIA or board-partner statement either way on software undervolting or power limits. Check your card's warranty terms. Hardware changes such as shunt mods are a different matter, and we don't recommend them.
- The connector: lower power reduces current, but a 2026 melt happened on a card capped at 500 W. Undervolting doesn't replace proper cable seating; see our power-connector guide.
Should you undervolt?
If your PC runs hot, loud or near its power supply's limit, a power limit is an easy first step, and an undervolt can recover most of the speed it costs. If you run AI jobs for hours, a 400–450 W limit trades a few per cent of throughput for meaningfully less heat and energy. If you game at 1440p or with frame generation, where the card often isn't at full load anyway, the difference may be smaller still; see why your RTX 5090 might never reach its full potential.
Buying in Singapore
RTX 5090 cards are not in stock at SourceIT at the time of writing; ask us about availability and a quotation. If you run a GPU workstation for long AI jobs, protect it with a UPS sized to its real draw. The APC Back-UPS Pro Gaming 2200VA (pure sine wave, 1,320 W) is S$645.00 (listed 6 Nov 2026). Prices change, so ask for a current quotation. Use Request for Quotation on the product page, call (65) 6978 3502, email Sales@sourceit.com.sg or use our contact page.
Frequently asked questions
How much performance do you lose by undervolting an RTX 5090? Community results show 0–2% for a 13–18% power cut with a good undervolt. A plain power limit costs more: about 5% at 450 W and 10% at 400 W in ComputerBase's tests.
What is a good power limit for an RTX 5090? About 450 W is a common starting point for gaming. A community AI test recommended 400 W for always-on inference and 400–450 W for training.
Does undervolting void the warranty? We found no official statement either way. Software settings are reversible, but check your card's warranty terms. Don't make hardware modifications.
Does a lower power limit slow down local AI? Single-user text generation barely changed at 400 W in one test. Training, image generation and many-user serving slowed by about 5–11%.
Will undervolting stop my power connector melting? It reduces current but isn't a fix. A melt was reported on a card capped at 500 W, so seat and route the cable properly as well.
SourceIT Approved
Researched and verified by the SourceIT team for Singapore buyers.
