NZXT Sentry LX Fan Controller Review

The Smith - 2008-08-07 07:53:55 in Cooling
Category: Cooling
Reviewed by: The Smith   
Reviewed on: August 14, 2008
Price: TBD


Each and every computer needs to be adequately cooled. There exist many ways of doing this, but most of them are cooled using air, which is powered by fans. However, if the fans are not adequately controlled, this cooling method can be quite noisy, or not perform as well as it could, because quiet operation does not always go together with performance. Moreover, you need a way to watch your computer temperatures, especially if you are an overclocker, as they can become fatal to your hardware.

This is why a fan controller and temperature probes are a must. These will allow you to watch your computer temperatures carefully, in addition to having absolute control over the cooling system. A device that combines all these functions is the Sentry LX, an aluminum high performance fan controller made by NZXT. This is the second version of the Sentry, since the first one was released in 2007; its review can be found here. The new one features five temperature probes and can control up to five fans, automatically or manually. The control unit is inserted into two adjacent empty drive bays, and shows all the information on a LCD screen. So, let's go see how the Sentry LX compares to its predecessor.


Closer look:

The Sentry LX is packaged in a simple yet attractive cardboard box. Naturally, there is a picture of it on the front, on a white background. On the back, the detailed specifications can be read. NZXT also tells us that the Sentry LX has an LCD display with an intuitive interface, and that it is easy to use and install. We'll see if it's true.


The unit is hung right in the middle of the box by two foam blocks, one on each side. It is wrapped in a plastic bag; however, it's not an anti-static one. The accessories can be found in a separate bag, which we will see in the next few pictures.


Obviously, there is a user's manual supplied. You also get a 3v lithium battery, two spare temperature probes with their wires, and a few orange stickers. You'll ask what those are for, huh? Well, I wondered myself for a long time; there is nothing said in the manual about them. I finally discovered that these are the plastic stickers for the temperature probes.

A sticker protects the LCD display, which has a non-glossy finish to prevent light reflections. Its non-rectangular shape is part of the nice design. The smaller left part of the screen is there to display the date and time, and the bigger right part is where the primary functions are displayed. The buttons are well labeled; you easily hear a "click" when you push them.












The thin aluminum structure has a black finish. As you can see, the printed circuit board is not hidden at the back, so there is a minimum amount of material used; this makes the unit lighter, but its robustness is not sacrificed.


There are many components glued on the printed circuit board. These include some capacitors, and the temperature probes connectors. Each of them, and also each fan, has its own connector - which is great. To get better wire management, you can disconnect what you are not using; but in order to do that, you will first need to peel off the hot glue. On the pictures below, you can also see where you need to install the supplied battery. Like on a motherboard, it is to keep your settings, and also keeps the clock running.


A Molex connector is used to power the fan controller, as well as the connected fans. As you can see, the five fan connectors and probes are labeled from 1 to 5. When using the automatic mode, fans will adjust their speed in accordance with their respective probes. For example, fan 3 will work in conjunction with probe 3. I left some protectors on the temperature probes to show you that they were well protected, which is a good thing, because they can easily be damaged. You can also see that all of their wires join together to form a flat cable - but don't be afraid, you can easily peel each wire apart from another.


In the next pictures, you can see the Sentry LX working. Its black finish fits well in a case of the same color. As you can see, a fan is plugged in the fifth connector. The Sentry LX displays its speed, and an image of the small blades turning. In the first picture, the fan is running at full speed; in the second one, I slowed it to 800 RPM. The blue bars under the speed adjust accordingly.



Installing the NZXT Sentry LX is as simple as installing an optical drive into a 5.25 inch bay. All you need to do is to open two empty adjacent drive bays. Then, insert the unit face out, securing it to the drive cage using screws or a tool-free device. Unfortunately, the screws are not provided with the fan controller, so if you absolutely need to use screws, you will need to get them elsewhere.












Then, you just need to connect the fans to the headers. As you probably noticed, only fans using 3-pin connectors can be plugged in. Those with four pins, such as the processor heatsink plug, and those using Molex connectors, can't be plugged in. That left me with only two fans I could control. As for the temperature probes, you can place them wherever you want. They can be put on the side of a processor heatspreader, but they will always indicate lower temperatures compared to the integrated temperature probe. That is normal, since the probe is not inside, like the integrated one. So, they are the most effective for reading the temperature of items that the probe can be attached to, such as hard drives, chipset heatsinks, ambient air temperatures, and just about anything you can attach the probe to.


I also want to warn you that you should not put a probe directly between the processor and the heatsink. The small bump will prevent good contact between the CPU and HS/F, and you might cause overheating.



The instructions for setting the Sentry LX up are clearly explained in the user's manual. You can't go wrong if you follow these steps. To show you how easy it is, I will explain it in my own words:




I first began to test the Sentry LX's features, but in doing so, I encountered a defect with the Temperature Alarm. In the user's manual, NZXT says that it is supposed to ring when a fan is detached during operation. That function simply does not work. Later, I discovered that it rings when a temperature probe is disconnected! So it is probably a misconception or user's manual error, but I would think it's supposed to ring when the fan is disconnected, and not a probe, like on a motherboard.

I am also going to test the accuracy of the Sentry LX. I am not going to compare its temperatures to the ones of SpeedFan, because we know that they are not going to be the same as internal probes, as I said earlier.

So first of all, I needed to get another tool to compare. Measuring up to 1/10 of a degree would be a plus, since the Sentry LX does. So I bought an infrared temperature reader. To compare the results, I am going to test them at room temperature, and also at colder and hotter temperatures. To get these, I will make perform test in the fridge, and another one in the oven. But when I began the test, I took the fridge temperature using the infrared temperature reader, and I was getting negative results, ranging from -10C to 2C. Seeing those numbers, I dismissed the idea of using this tool, and I came back with a good old alcohol thermometer. I had one specially designed for yogurt making, which is supposed to be very accurate, so all of the tests will be run using it.

Since I am not going to use the infrared temperature reader, I want to point out that the two devices I will compare don't have the same accuracy. For a digital tool such as the Sentry LX, it is the smallest unit measured, therefore 1/10 of a degree. For a visual tool such a thermometer, it is widely accepted that the accuracy is half of the smallest unit. Since we can only tell if it's between the lines, this means jumps of 0.5C, and not of 0.1C.

Testing Setup:


Comparison devices:


First of all, I verified if the Sentry LX probes were reading the same temperature in the same location. I bound them together using an elastic band, and I left them for a few seconds. The five probes were all indicating 25.9C. I hoped they would, because this would have meant a lack of accuracy, straight at the beginning.





As you can see, the temperatures were extremely close, and well between the accuracy ranges; I could not have determined if it was 3.9C or 4C on the thermometer. However, at high temperatures, there was a 1C difference between the two. In this test, due to wire length, the probe was very close to the oven door, where the heat can escape. So again, due to the very small difference, accuracy of both devices and circumstances, I can't tell if this marginal 1C difference was caused by a lack of accuracy. Therefore, I consider the NZXT Sentry a very accurate tool to monitor temperatures. It would not have been the case with a 3C difference, though.

I also want to say that I was impressed by how fast changes in temperatures are detected by the Sentry LX. For example, when I was simply touching a probe with my finger, the displayed temperature instantly jumped from 26C to 33C, instead of rising gradually.


The NZXT Sentry LX is a nice tool to add to your air cooling system, and it allows you to get the most out of your fans. When it's time to keep your components cool during a gaming session, it speeds up the fans. When it's time to read an e-book, and the PC is idling, it slows the fans down to reduce noise. Moreover, it displays up to five temperatures, directly on your case's drive bays, which is very useful.

Compared to its predecessor the Sentry 1, the LX can control three more fans and gather two more temperature readings. It's a good thing, because nowadays, cases tend to have more and more fans. The fact that it occupies two drive bays instead of one allows for a bigger screen to display all of the information at the same time. So you don't need to push any buttons to see the information you want, something that you needed to do with the Sentry 1.

I was also very impressed by the accuracy of its temperature readings. Not only is it as accurate as a good old alcohol thermometer, it also meant that the changes in temperatures are detected instantly. Seeing these results, I can't do anything else but trust the readings shown by the NZXT Sentry's display screen. I will even use it to gather the room temperature for my next reviews.

However, the fact that you can only connect 3-pin fans is very disappointing, and it is by far its biggest con. Adapters could have been supplied to fix that, at an added cost, of course. There's also the non-existent fan disconnection alarm, which turned out to be for the temperature probes. It is written in the user's manual that it rings if a fan is disconnected! So we have here either a conception or manual error (note the online manual corrects this issue). Even with these cons, the Sentry LX is still an amazing product. I would still feel comfortable recommending it to everyone who wants to control their air cooled system, and to watch their temperatures. What self respecting overclocker does not do that?