Review: Jonsbo D40





The additional ventilation takes the form of a Fractal Silent Series R2 fan placed at the rear in suction and a Riing 14 positioned in suction at the bottom.

CPU airflow, original ventilation then supplemented:

We start first with the temperature of our CPU. We keep the front and the top of our test case. Let’s see if the airflow is sufficient for the good cooling of the Ryzen 7 1700X.

Température CPU

Overall, we can say that our little Ryzen 7 1700X is hot in this case. Remember that the D40 does not have a fan, so we have to rely on the natural convection of the case to extract the hot air… Here we find 67.4°C in the basic configuration of the Jonsbo case.

The addition of a fan in aspiration at the back, will greatly help the cooling of our processor. Thanks to a small mill, we lose more than 10°C on its temperature, so it is imperative!

CPU airflow original ventilation without front panel or top :

In order to ensure the limiting factor in the story (and how much), we remove the top as well as the front of the case. The goal here is to show the raw performance of the integrated ventilation.

Températures CPU sans façade

Without the top of the case (the front panel is not removed), and without additional fans (standard configuration), we gain a little less than 2°C on the CPU. A result that means that the processor is not too suffocated either.

GPU airflow, original ventilation then completed :

We repeat the operation, but with measurements made on the graphics card. Here, we test with original ventilation and completed ventilation.

Températures carte graphique

However, the component that suffers the most in this D40 is clearly our graphics card. As we can see, with 97°C, it is essential to do something. The addition of a simple fan at the bottom allows us to gain a lot in temperature. With a Riing 14 fan, we lose 24°C, so don’t deprive yourself!

GPU airflow original ventilation without front panel or top:

We redo the same test, but removing the front panel and the top of the case. Let’s see how this will affect the temperatures of the card.

Températures cartes graphique sans façade

Removing the top part of the case facilitates the extraction of hot air from the case. By removing it, the GPU blows a little, although stabilized at an alarming temperature: 93°C


Here we simply measure the noise emitted by our config when running the CPU cooling and GPU cooling very fast.

Jonsbo D40 Isolation

On the other hand, the insulation side is a good surprise since our model of the day is particularly efficient. With the GPU blower running at 75%, we found a noise level of 52.5 dB. The natural isolation of the D40 is very effective and should guarantee a good level of silence during daily use.

Original fan noise:

This time we measure the noise emitted by the original ventilation of the case. To do this, the configuration runs in idle ( CPU and GPU ventilation at minimum) while the readings are taken successively in 5V, 8V and 12V on the case ventilation.

Jonsbo D40 bruit

On the noise side, there is no secret, without a basic fan, the case remains very quiet with only 31 dB of reading. Of course, you can hear the hard disk and the fan of the Dark Rock 4

Bottom line:

The first thing to remember with this Jonsbo D40 is that you MUST add fans inside. If you don’t, you risk having a machine that will suffocate because of indecent temperatures. As we saw, our HD 7970 reached dangerous temperatures that immediately went away as soon as we added a fan underneath. The same goes for the CPU, which gained almost 10°C after adding a mill at the back. Finally, what this model lacks is an airflow brought by fans!

Otherwise, we are surprised by the isolation capacity of the D40 since it is the most efficient in this respect among our panel. If you want to build a quiet configuration, this might be a model to consider