Comparison Zalman Z9 U3 black vs Zalman Z9 Plus without PSU

The maximum length of a graphics card that can be installed in this case.

Modern mid-range and top-end video cards with high performance often differ in considerable length, which is why such a card can not fit into any case. So before collecting components, it is worth evaluating the length of the proposed graphics card and choosing a case in which it is guaranteed to fit. This forethought is useful anyway, but it's especially true if you're building a system that requires a powerful graphics adapter, such as a high-end gaming PC or 3D design workstation.

The number of internal 2.5" bays provided in the case design.

Such bays are mainly used for installing internal hard drives and SSD modules; The 2.5" form factor was originally created as "laptop" form factor, but recently it has been increasingly used in components for full-size PCs. At the same time, when evaluating the number of these bays, note that drives are recommended to be installed through a slot; so in Ideally, the number of bays should be twice the planned number of drives.

Also note that some cases use combined bays: initially they have a size of 3.5", but if desired, they can be converted to 2.5". These bays count towards both 3.5-inch and 2.5-inch slots. In fact, this means that the total number of available slots is not always equal to the sum of the number of both. For example, a case with 10 3.5" bays and 6 2.5" bays can have 4 combined bays, and the total number of slots in this case will not be 16, but only 12.

The more fans are included in the design, all else being equal — the more intense the cooling will be and the more powerful (and, consequently, "hotter") components can be placed in the case without the risk of overheating. For everyday tasks, a case with one, two, three, or four factory fans is quite sufficient. At the same time, when comparing, it is worth considering not only the number but also the operating characteristics of the fans (diameter, speed). It should also be noted that cases are available for purchase without fans but with open slots for fans, allowing you to supplement the cooling system and improve its performance if necessary.

The ability to manually control the rotation speed of the fans installed in the case.

This function allows you to adjust the operation of the fans to the specific situation. For example, in cool weather with a light load, you can reduce the speed (or even turn off the fan altogether), reducing power consumption and noise level, and increase it when starting a demanding game. Also note that there are software tools that allow you to automatically adjust the speed of the fans; so that instead of manual control, this function can be entrusted to automation.

The fan control system is usually equipped with the most advanced case models.

The number of built-in USB-A 2.0 ports provided in the case.

These ports are usually located on the front side. They are most convenient for peripherals that need to be frequently connected and disconnected, such as "flash drives" (for permanently connected devices, it's more convenient to use the motherboard ports located on the rear panel). Specifically, USB 2.0 is considered outdated these days: it provides a data transfer speed of only 480 Mbps and comparatively low power. Nevertheless, in many cases, this is quite sufficient, and USB-A 2.0 ports continue to be used, even in fairly advanced cases.

Number of own USB-A 5Gbps ports (previously labeled as USB 3.2 gen1 and USB 3.0) provided in the case.

These ports are usually located at the front (see "Placement" for more details). They are most convenient for peripherals that need to be frequently connected and disconnected, like flash drives (for permanently connected devices, it is more convenient to use motherboard ports routed to the rear panel). Specifically, the 5Gbps standard replaced the above-mentioned USB 2.0, offering 10 times faster data transfer speeds (up to 4.8 Gbps) and higher power output, while USB 2.0 standard peripherals can also be connected to these ports.

It should be remembered that for proper port functioning, their quantity and versions must match the capabilities of the motherboard.

— Front Cover. A flap cover that entirely or partially conceals the front panel. It gives the computer a neat appearance by hiding ports and external slots under a uniform surface and serves as childproof protection.

— Panel Display. A display on the front or side panel of the case used to show various service information: current CPU frequency, system temperature data, cooling mode, etc. Various important data can be displayed independently of what happens in the software part of the computer.

— Graphics Card Holder. A structural solution for supporting the graphics card inside the case. Specialized stands or holders prevent the graphics adapter from sagging over time and reduce the strain on the PCI-E slot of the motherboard. The fact is, many modern graphics card models have significantly increased in weight — holders are designed to compensate for their heaviness. Stands are available as built-in solutions or standalone accessories that can be installed inside the case independently.

— Side Panel Lock. A special lock on the removable side panel of the case. Such a lock prevents unauthorized access to the internal space of the system unit.

— Noise Insulation. The presence of additional noise insulation in the case. This can be a special coating on the interior sid...e or other, more specific solutions (e.g., damping systems on "mounting spots" for individual components, reducing the level of vibrations transmitted to the case). In any case, this feature helps reduce the noise level emitted by the system — sometimes quite significantly.

— Removable HDD Cage. The presence of a removable cage under the internal peripherals of 3.5" form factor (in most cases these are hard drives, hence the name) in the case design. This cage facilitates assembly because removing and installing a hard drive is much easier than securing it in a non-removable slot inside the case; this aspect is particularly useful if the system plans to install multiple hard drives.

— HDD Docking Station. Built-in docking station for quick connection of internal hard drives. In fact, this feature allows connecting an internal HDD as an external one: the docking station port is located outside the case and equipped with quick-connect fasteners for convenient connection.

— Hidden Cable Routing. The ability to route cables from the power supply on the reverse side of the motherboard (considering the main side where the processor and expansion card slots are located). Thus, the main "mobo" side is freed from cables, positively affecting cooling efficiency.

— Cooling System Installation Window (CS) for the processor. The presence of a separate window in the case opposite the CS mounts for the processor. The fastening system is located on the reverse side of the motherboard, and usually, replacing it requires removing the entire "mainboard"; the CS installation window frees the user from this necessity and significantly simplifies the installation and replacement of CS.