Every DIY PC build requires a basic understand of which components to choose and how to assemble them, but SFF (small form factor) and passive cooled systems (fanless computers) do require a higher level of competency and knowledge. This guide provides general tips and suggestions on what should be considered when building in a Streacom computer case and how to achieve the best results.

Selecting a CPU
Two factors will determine the choice of CPU:

1. Thermal Design Power (TDP) – How much heat is the CPU going to generate
2. Power Consumption – How much power the CPU uses

Both of these are measured in Watts (W) and typically will have values ranging from 35 to 125+ Watts depending on processor performance and efficiency. All CPU’s have their TDP value marked, but a comprehensive list of CPU TDP’s can also be found here: Intel / AMD CPU’s

Below are the maximum recommended TDP values for our passive cooled cases. For our non passive cases (F1C, F7C) the max TDP will depend on which CPU cooler is purchased and of course the power supply limitations.

Model FC5 FC8 FC9 FC10 DB4 DB4+LH6
Max TDP 73W 95W 73W 95W 65W 110W
Apart from the maximum cooling performance of the case, you will also need to consider the power output limits of the PSU. Check the ‘Power Supply’ tab for further information on working out the approximate power load for your build.

Socket Support
For “FC” Model cases we supply both Intel® and AMD® brackets which are compatible with all current CPU sockets.

For “DB” Model cases we supply a universal mount that is compatible with both Intel® and AMD® sockets.

Selecting a Motherboard
One of the more challenging tasks is selecting a compatible motherboard. This is because components are often in the path of the heatpipes between the CPU and side of the chassis (heatsink). Compiling a comprehensive and up-to-date list of all compatible motherboards is simply not practical, so we have produced the diagrams below which detail the key measurements that are needed for selecting a compatible motherboard.

Motherboard CPU Positions
The key points to check are:
1. The location on the CPU on the motherboard is within the reach of the heatpipes (CPU Position Area).
2. There are no components which will interfere with the path of the heatpipes.

Select from the tabs below to view the heatpipe locations and motherboard examples for each of our fanless cases:

Calculate the System Power Requirements
Something that will influence the choice of every component you select is the power limit of the PSU. Small and fanless power supplies can not supply as much power as typical full size ATX actively cooled ones. It is therefore important to total the power consumption of each component you select to ensure the sum is less than the PSU’s maximum output. The table below shows typical component values when the system is in ‘normal’ use and at maximum load. You should always calculate with the maximum load to ensure the system will be stable in all situations.

Component Processor Motherboard RAM
Per Slot
Hard Drive Optical
Video Card PCI
USB Devices
45W 65W Basic Advanced SSD 2.5″ 3.5″ Basic Advanced 2.0 Port 3.0 Port
Typical Power Consumption 45W 65W 18W 22W 4W 1W 2W 3W 3W 25W 45W 5W 2W 3W
Max Power Consumption 58W 82W 30W 65+W 6W 4W 6W 15W 5W 45W 100+W 15W 2.5W 4.5W

So for example, a system with the following components would require:

1 x 65W CPU
1 x Motherboard
2 x 4GB RAM
1 x SSD
1 x Optical Drive
2 x USB3.0 Devices

CPU (82W) + Motherboard (30W) + RAM (12W) + SSD (4W) + Optical Drive (5W) + 2 x USB2.0 Devices (5W) = 138W Total

Please note that the figures above are typical, but just for reference. Actual figures should be verified with the component manufacturers.
Selecting a Hard Drive
For building a low power, low heat and responsive system, SSD’s are an ideal choice as they generally offer the best of all these 3 characteristics. However from a price prospective, they are still relatively expensive, so as an alternative, traditional spinning platter hard drives can be considered. Laptop 2.5″ drives will offer an advantage on power consumption and heat, but 3.5″ drives still offer the highest storage capacities, performance and the lowest price per GB. If you decide to go with traditional hard drives, selecting one with a lower spin speed should reduce power consumption, heat and noise from vibration. Typically these are referred to as ‘green’ or ‘eco’ drives.

If practical, you can consider an alternative approach by using a network attached storage (NAS) device in conjunction with your system. You can choose a low capacity SSD for your build, then place your high capacity network attached storage device (NAS) in a location where its not seen or heard. This solution is ideal for people with large media libraries and multiple systems.

If you are going to use 3.5″ drives for larger storage, note that there are standard height drives and “slimline” or “low-profile” drives available which measure 26mm instead of 42mm. These are especially useful in our smaller cases such as the F1C and F7C as they will allow for larger CPU coolers (taller/higher) which offer improved cooling and lower noise.

hard drive
Selecting an Optical Drive
All Streacom cases (excluding the WS versions that do not include any mounting or slot for an optical drive) require the use of a laptop slot loading optical drive. The standard height for these drives is 12.7mm and they are available with either a left or right side eject button. Cases that feature the ‘universal eject button’ can use either button position, otherwise a left side eject button optical drive must be used.

Laptop drives tend to be a little more difficult to install because of the small screws and tolerances. Most issues can be resolved by careful adjustment of the position (for eject button) and not over tightening the screws which secure it in place. If the drive does not function when installed, try loosening the screws to ensure they are not warping the drive in any way or blocking the mechanism internally.

Laptop drives also feature a smaller connector than those used on hard drives, so make sure you also purchase a ‘slimline’ SATA cable with both data and power so that you wont have any problems connecting the drive to your motherboard and PSU.

Selecting a Graphics Card
In general discrete graphics card will deliver higher performance than integrated solutions and are the preferred solution for gaming, however the tradeoffs come in the form of power consumption and heat. A list of GPU’s and their TDP’s can be found here Nvidia or AMD/ATI. It is therefore preferable to use an integrated graphics solution, with the current breed of products being more than capable of delivering the type of performance required for the majority of applications.

Discrete graphics cards tend to be fairly power hungry, so make sure your PSU can handle the extra load.

Card Length
The maximum length (L) and height (H) of any expansion card that can fit is shown below for each chassis. Note that the height must also include AUX power connectors if they protrude from the card.

Model FC5 F7C/FC8 FC9 FC10 F12C DB4
Max Length 180mm 230mm 147mm 178mm 310mm 200mm
Max Height NA* 80mm 80mm NA 130mm 116mm

*Limited to Half Height cards when using the ZF240 PSU
General Points for Consideration
Heat transfer has 3 common modes of operation, radiation, conduction and convection, with conduction and convection being the primary methods that all CPU coolers use. Our passive cooled cases operate in the same way as conventional fan blower CPU coolers except we do not use a fan. Our cooling relies on the large surface area of the heatink (side of the case) and instead of forced air which removes the heat (through forced convection using a fan), convection from the natural airflow caused by the heatsink warming the adjacent air.

It is therefore important when placing a passively cooled system to properly allow for sufficient airflow. Positioning the chassis in an enclosed environment or one with poor air circulation will lead to the system overheating as there will be insufficient cool air passing over the heatsink to transfer the heat away from the chassis.

Another key element of the cooling solution is the heatpipes which transfer the heat from the CPU to the heatsink. The basic principle of a heatpipe is the transfer of heat from a high temperature area to a low temperature area through the mechanism of evaporation and condensation (phase change). The heatpipes contain a ‘working fluid’ (in our case water) and should therefore never be cut or damaged in any way as that would allow the fluid to escape, render the heatpipes useless. Heatpipes are hollow to allow the working fluid to move, so whilst they can be bent and shaped, any sharp bends will cause the hollow center to be blocked causing poor performance. In general the heatpipes should be handled with care to avoid any of these problems. heatpipe
Customer Feedback
As with everything we do at Streacom, we would like to hear from you, our customers, on how we can improve this guide. We appreciate it might not cover every situation or question, but if enough customers are experiencing the same difficulty, we will do our best to add information that will help.

If you would also like to submit a motherboard for us to list as ‘compatible’ then please send us the model along with a link showing it correctly installed and we will share this information with other customers.

Please note that this contact form is specifically for feedback on the build guide and website content. If you are having support issues or have hardware compatability questions, please contact support using the form on the contact page.

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