Fans are everywhere, cooling down sensitive to heat electronic devices. They are often overlooked unless noisy because they just do their job for long periods until they stop spinning.
The most popular bearing types used in PC cooling fans are the following:
● Sleeve bearing
● Rifle bearing
● Double ball (DBB) bearing
● Fluid dynamic bearing (FDB) and hydro dynamic bearing (HDB)
● Magnetic bearing
We named our fan performance standard Phi after the Greek letter «Φ,» which represents the golden ratio.
All fans that can reach it are rated at 25 dBA normalized noise output, and we take into account these results to rank them in the following categories. Why did we choose this specific noise level for our standard? Because at 25 dBA, a fan can spin fast enough to achieve decent performance, while this noise level isn’t high enough to annoy the majority of users. Anything higher or lower than this noise level would be too noisy, or performance would be hugely affected.
Requirements raised on 3 October 2026. We raised the Platinum, Titanium and Diamond requirements, for both airflow and static pressure and for both fan categories, so that Diamond is reserved for the very best fans. Gold now ends where the new Platinum starts; the Silver and Bronze requirements did not change. Every fan in our database was re-rated with the new requirements on the same day, from its existing measurements; no fan was measured again.
What about fans that cannot reach 25 dBA, even at full speed? These fans are designed for very low noise output, so they cannot be compared with other fans at 25 dBA. Rating them at full speed would not be a fair comparison either, since their noise output would then differ from that of the fans they are compared with. For these fans we use the next normalized noise output level of our test routine, 20 dBA. A 120mm or 135/140mm fan whose maximum noise output is below 25 dBA but reaches 20 dBA is rated with the airflow and static pressure measured at 20 dBA normalized noise output, against the 20 dBA requirements listed below. A fan that cannot reach 20 dBA, even at full speed, does not receive a performance level.
The 20 dBA requirements express the same performance levels at the lower noise output; they are not a separate standard. We derived them from our fan database in October 2026. For every fan measured at both 25 dBA and 20 dBA normalized noise output (143 fans of 120mm and 51 fans of 135/140mm), we calculated the ratio of its airflow, and of its static pressure, at 25 dBA to the same value at 20 dBA. Each 25 dBA requirement was then divided by the median of these ratios: 1.221 for the airflow and 1.429 for the static pressure of 120mm fans, and 1.196 and 1.386 respectively for 135/140mm fans. These ratios are fixed and are not recalculated as new fans are tested.
Rating the same fans with both sets of requirements, the level obtained at 20 dBA is the same as the level obtained at 25 dBA for 69% to 88% of them, depending on the category, and only 2 of the 388 comparisons differ by more than one level. The rating of a fan at 20 dBA is always based on its own measurement at 20 dBA normalized noise output; the ratios are used only to set the requirements, never to estimate a fan’s performance at 25 dBA. When a fan is rated at 20 dBA normalized noise output, the evaluation report states this noise level next to the rating.
PFPS – 120mm Fan Airflow Levels/Requirements – 25 dBA Normalized Noise Output
| Performance Levels | Requirements
|
|---|---|
| Bronze | ≥34 CFM & <38 CFM |
| Silver | ≥38 CFM & <42 CFM |
| Gold | ≥42 CFM & <48 CFM |
| Platinum | ≥48 CFM & <53 CFM |
| Titanium | ≥53 CFM & <57 CFM |
| Diamond | ≥57 CFM |
PFPS – 120mm Fan Static Pressure Levels/Requirements – 25 dBA Normalized Noise Output
| Performance Levels | Requirements
|
|---|---|
| Bronze | ≥0.8 mmAq & <1.0 mmAq |
| Silver | ≥1.0 mmAq & <1.25 mmAq |
| Gold | ≥1.25 mmAq & <1.65 mmAq |
| Platinum | ≥1.65 mmAq & <2.1 mmAq |
| Titanium | ≥2.1 mmAq & <2.5 mmAq |
| Diamond | ≥2.5 mmAq |
PFPS – 135/140mm Fan Airflow Levels/Requirements – 25 dBA Normalized Noise Output
| Performance Levels | Requirements
|
|---|---|
| Bronze | ≥45 CFM & <50 CFM |
| Silver | ≥50 CFM & <55 CFM
|
| Gold | ≥55 CFM & <62 CFM |
| Platinum | ≥62 CFM & <67 CFM |
| Titanium | ≥67 CFM & <72 CFM |
| Diamond | ≥72 CFM |
PFPS – 135/140mm Fan Static Pressure Levels/Requirements – 25 dBA Normalized Noise Output
| Performance Levels | Requirements
|
|---|---|
| Bronze | ≥0.7 mmAq & <0.9 mmAq |
| Silver | ≥0.9 mmAq & <1.1 mmAq |
| Gold | ≥1.1 mmAq & <1.5 mmAq |
| Platinum | ≥1.5 mmAq & <1.85 mmAq |
| Titanium | ≥1.85 mmAq & <2.3 mmAq |
| Diamond | ≥2.3 mmAq |
PFPS – 120mm Fan Airflow Levels/Requirements – 20 dBA Normalized Noise Output (fans that cannot reach 25 dBA)
| Performance Levels | Requirements |
|---|---|
| Bronze | ≥27.8 CFM & <31.1 CFM |
| Silver | ≥31.1 CFM & <34.4 CFM |
| Gold | ≥34.4 CFM & <39.3 CFM |
| Platinum | ≥39.3 CFM & <43.4 CFM |
| Titanium | ≥43.4 CFM & <46.7 CFM |
| Diamond | ≥46.7 CFM |
PFPS – 120mm Fan Static Pressure Levels/Requirements – 20 dBA Normalized Noise Output (fans that cannot reach 25 dBA)
| Performance Levels | Requirements |
|---|---|
| Bronze | ≥0.56 mmAq & <0.70 mmAq |
| Silver | ≥0.70 mmAq & <0.88 mmAq |
| Gold | ≥0.88 mmAq & <1.15 mmAq |
| Platinum | ≥1.15 mmAq & <1.47 mmAq |
| Titanium | ≥1.47 mmAq & <1.75 mmAq |
| Diamond | ≥1.75 mmAq |
PFPS – 135/140mm Fan Airflow Levels/Requirements – 20 dBA Normalized Noise Output (fans that cannot reach 25 dBA)
| Performance Levels | Requirements |
|---|---|
| Bronze | ≥37.6 CFM & <41.8 CFM |
| Silver | ≥41.8 CFM & <46.0 CFM |
| Gold | ≥46.0 CFM & <51.8 CFM |
| Platinum | ≥51.8 CFM & <56.0 CFM |
| Titanium | ≥56.0 CFM & <60.2 CFM |
| Diamond | ≥60.2 CFM |
PFPS – 135/140mm Fan Static Pressure Levels/Requirements – 20 dBA Normalized Noise Output (fans that cannot reach 25 dBA)
| Performance Levels | Requirements |
|---|---|
| Bronze | ≥0.51 mmAq & <0.65 mmAq |
| Silver | ≥0.65 mmAq & <0.79 mmAq |
| Gold | ≥0.79 mmAq & <1.08 mmAq |
| Platinum | ≥1.08 mmAq & <1.33 mmAq |
| Titanium | ≥1.33 mmAq & <1.66 mmAq |
| Diamond | ≥1.66 mmAq |
Since we don’t want to confuse users, we used the highly familiar metal and carbon ratings that we already use for our PSU efficiency ratings: Bronze, Silver, Gold, Platinum, Titanium, and Diamond.
There are two fan categories, the most popular ones: 120mm and 135/140mm. Larger fans, such as 148mm and 150mm models, are rated with the 135/140mm requirements at 25 dBA normalized noise output; the 20 dBA route is not available to them, so a larger fan that cannot reach 25 dBA does not receive a performance level. There are also two badges for the fan’s main performance factors: airflow and static pressure.
Decision Rule
Badges are awarded by direct comparison of the measured value at 25 dBA (or at 20 dBA, for 120mm and 135/140mm fans that cannot reach 25 dBA) with the corresponding requirements above, without adjusting for measurement uncertainty. Where a fan measures within one expanded uncertainty of a level boundary, we re-test it three times and use the mean; if it is still that close, we award the lower level. Measurement uncertainties are stated in the Fan Test Protocol.