In recent years, PC case design has shifted toward panoramic enclosures that prioritize visibility and a clean internal layout. The so-called “fish tank” style has become particularly popular among enthusiasts who want to showcase high-end hardware while maintaining efficient airflow. Jonsbo has been active in this space for some time, offering products that combine careful design with solid functionality. The BO400 is their latest entry and arrives with a focus on both aesthetics and expandability.
The JONSBO BO400 adopts a rectangular, open-layout design with tempered glass panels that allow a clear view of the system interior. Jonsbo has opted for a refined look, emphasizing smooth edges and precise construction rather than unnecessary visual clutter. The result is a chassis that feels well-built and suitable for a range of setups, from gaming systems to professional workstations.
In terms of hardware support, the BO400 provides flexibility for demanding builds. It accommodates ATX motherboards, graphics cards up to 435 mm, and offers cooling options with mounting for up to ten fans. The internal layout also includes practical features such as a pre-installed GPU support bracket and structured cable management channels, which contribute to easier assembly and a cleaner final system.
For this hands-on review, a complete system was assembled inside the BO400 to assess its overall build quality, installation process, and thermal performance under stress. This approach allows us to determine whether the case meets the requirements of modern high-performance components while maintaining the level of finish and usability expected in today’s market.
Specifications
| Specification | Details |
|---|---|
| Model | JONSBO BO400 |
| Case Material | SPCC Steel & SGCC Steel |
| Dimensions (D × W × H) | 474mm × 311mm × 489mm |
| Motherboard Support | MINI-ITX / MICRO-ATX / ATX |
| Drive Bays | 2.5″ SSD: up to 2 3.5″ HDD: up to 4 |
| Front I/O Ports | 2 × USB 3.2 Gen1 Type-A 1 × USB 3.2 Gen2 Type-C 1 × Audio 1 x Mic |
| Fan Support | Top: 3×120mm / 2×140mm Rear: 1×120mm Bottom: 3×120mm / 2×140mm Side: 3×120mm |
| Radiator Support | Top: 240mm / 280mm / 360mm Side: 360mm Bottom: 240mm / 280mm / 360mm |
| PSU Clearance | ATX PS2, ≤200mm |
| CPU Cooler Clearance | 173mm |
| GPU Clearance | Up to 435mm |
| Weight | N.W. 12.9kg / G.W. 18.3kg |
Unboxing
The Jonsbo BO400 is shipped in a plain, durable cardboard box with minimal graphics. The front side shows the sub-brand name “JONSPLUS” vertically along the right side, while the front clearly shows the model name “BO400” in large print, along with the description “ATX Computer Chassis” and a note highlighting its aluminum frame and back-connect design. A simple line sketch of the case gives a first look at its compact structure. On the back, a diagram illustrates the chassis components, including the panels and frame, offering a clear overview of how the case is put together before opening the box.
The Jonsbo BO400 arrives well protected, with two thick foam pads and a black fabric bag that prevents dust and scratches during shipping. The accessory box includes more than just the basics. Along with screws, cable ties, and the user manual, Jonsbo provides a top glass panel, a graphics card bracket column, a support bracket with silicone spacers, motherboard standoffs, an installation aid sleeve, and fan mounting rod screws.
For those who prefer a cleaner look, the glass panel can be swapped with the default mesh cover, though this change will slightly reduce cooling efficiency. This approach allows users to choose between appearance and airflow depending on their build priorities.
Design
Exterior
The Jonsbo BO400 takes a different approach to case design, focusing on both structure and appearance. It is built from an aluminum alloy frame that provides strength and rigidity while keeping a refined, industrial look. The frame is produced through die-casting and CNC machining, giving it a skeleton-like layout that supports a large tempered glass side panel. This allows a clear view of the installed components while keeping the overall design balanced. Measuring 474 × 311 × 489 mm, the case provides sufficient room for modern hardware, and its aluminum build helps prevent warping or bending. Offered only in Silver-Gray, the BO400 delivers a clean and durable finish suited for gaming systems or professional use.
The BO400 chassis is built with a modular approach that gives users several options for panel configuration. By default, it includes tempered glass on the left and front, combined with a metal mesh top to support airflow. The top panel can be replaced with tempered glass to create a full three-glass layout, or users can choose to place mesh on the front while keeping glass on the side and top. These interchangeable panels allow builders to prioritize either cooling performance or a cleaner showcase of internal hardware, depending on their preference.
The BO400 is built with a frame that combines 12 straight columns and eight curved aluminum alloy joints, produced through hollow die-casting to increase rigidity and durability. This structure provides firm support while keeping a clean and balanced appearance. For easier assembly, the case includes built-in sliders on both sides that let users remove panels with a press button, while the top, bottom, and sides use tool-free snap-on fittings. These additions help simplify hardware installation, make regular maintenance faster, and keep the overall construction secure.
The BO400 features a front panel crafted from 6 mm CNC-milled aluminum alloy with an anodized brushed finish that gives the surface both strength and texture. The overall design follows a clean, minimal layout with a solid build that avoids unnecessary accents. At the bottom corner on the right side, the JONSPLUS BO400 branding is engraved, providing a simple but clear identifier that blends with the case’s design.
On the right side of the tempered glass panel, an aluminum I/O section with a brushed surface is arranged vertically for easier access. It includes a power button, ARGB control keys, a combined audio jack, two USB 3.2 Gen1 Type-A ports, and one USB 3.2 Gen2 Type-C port, covering common connectivity needs. A beveled groove runs along the panel, adding a subtle detail while also improving grip.
The case includes a side glass panel with a light matte black tint that slightly softens the glow from internal RGB components. This effect works well with the frame’s color, giving the build a cohesive look. Using matte black glass helps maintain a consistent style, but it’s still important to coordinate the RGB lighting inside to keep the overall appearance balanced. The side panel opens with a button. When the button is pressed, the glass panel drops down, and you need to hold it with your other hand to keep it from falling.
The rear side panels of the motherboard are made of steel and include openings for side fans and power supply installation, which help with airflow and heat management.
A magnetic dust filter is built into the panel to reduce dust buildup while maintaining cooling efficiency.
The case has full mesh panels on the top and bottom, each with a magnetic dust filter. This setup improves airflow and helps prevent dust from reaching the components. The filters can be easily removed and reattached, making routine cleaning simple.
The rear of the case has a dual-chamber layout and supports a 120 mm exhaust fan. Eight PCIe slot positions come with a reusable baffle, though the horizontal bar design may require checking compatibility with some graphics card stand brackets. Velcro cable ties behind the motherboard tray help organize USB and other peripheral cables. The power supply mounts on the left-center, while the 120 mm rear fan area is surrounded by perforated mesh to aid airflow. The I/O shield cutout is sized to fit most motherboards without forcing alignment.
Interior
The BO400 case supports Mini-ITX, Micro-ATX, and ATX motherboards, including Back-Connect layouts for organized cable routing. It can accommodate graphics cards up to 435mm long and CPU air coolers up to 173mm tall, allowing for larger components. Storage options include two 2.5-inch SSD bays in the rear compartment and up to four 3.5-inch HDDs, which can be mounted internally or externally. The design provides ample space for installation and cable management, helping keep the system organized.
The BO400 chassis supports graphics cards up to 435mm and includes a four-position height-adjustable aluminum bracket to prevent GPU sag. A bottom-mounted direct-blowing fan provides cooling for high-performance GPUs such as the RTX 4090 and 5090, helping maintain stable performance under heavy workloads. Cable management is handled with a cover for standard ATX motherboards and 24-pin power cables, keeping the interior organized. The front cable management cover is decorative and must be removed before installing the motherboard to ensure proper fit.
The case supports up to ten 120mm fans and can fit three 360mm radiators at the same time. The top panel accommodates three 120mm or two 140mm fans, the rear has space for one 120mm fan, the bottom can hold three 120mm or two 140mm fans, and the side panel supports three 120mm fans. For liquid cooling, it allows 240mm, 280mm, or 360mm radiators on the top, bottom, and side, with additional clearance for a 173mm tower radiator. This setup provides the flexibility needed for advanced cooling configurations.
The BO400 case features top and bottom fan brackets with two width positions (12cm and 14cm), letting users adjust the fans to fit different sizes or cooling setups. In Skylight Mode, the radiator can be installed on the main panel with the fan on top, allowing air to flow both upward and downward. The top bracket can also be reversed to improve cooling near the lower part of the radiator. In Side-view Mode, the bottom fan can be positioned to show the lighting effects while keeping airflow efficient, giving users flexibility in both cooling and presentation.
The case includes a removable composite hard drive cage held in place by thumb screws at the bottom. Cable management is made easier with ample space, and the power supply bay can fit ATX units up to 200mm long. All I/O cables are black, which helps keep the interior organized.
Installation
The case supports both standard and reverse-connection motherboards. The Maxsun iCraft Z890 Arctic ATX Motherboard was installed in the JONSBO BO400 without any clearance problems, leaving enough room for cable management and hardware placement. The white PCB adds a brighter appearance to the build, though a black option would have matched the case more closely.
Cooling was handled by a TRYX Panorama SE 360 mm liquid cooler mounted at the top, while two ZB360R (reserve) infinity mirror fans were positioned on the side and bottom to help maintain airflow. A single 120 mm fan (standard) at the rear completes the setup, creating a balanced cooling system across the case.
The AORUS GeForce RTX 4080 SUPER MASTER fits comfortably inside the JONSBO BO400 case, which provides 435 mm of clearance for large graphics cards. There was plenty of room during installation, with no concerns about space or airflow.
The case is equipped with a reinforced aluminum alloy GPU support bracket that adds stability to the card. This holder offers four adjustable length positions and a stepless height adjustment, helping to keep the graphics card properly supported and preventing sagging at the front over extended use.
The BO400 case offers support for power supplies up to 200 mm, making it a practical choice for high-capacity units. Cable management is neatly arranged at the rear with channels and tie-downs that help maintain a clean layout. With accessible panels on each side, installing components is efficient, allowing hardware to be mounted and adjusted with minimal effort.
The BO400 Case presents a refined look with its ARGB lighting. Behind the matte black tinted side panel, the JOSNBO ZB360/ZB360R ARGB fans provide a uniform glow that works well with the curved lines of the chassis. The side-mounted infinity mirror enhances the lighting effect, creating a layered appearance that adds depth to the build.
On the front panel, a slim ARGB strip becomes active once connected to the motherboard, offering an additional accent to the overall illumination.
Testing and Performance
The Jonsbo BO400 was tested with a system built around the Intel Core Ultra 7 265K processor, installed on the Maxsun iCraft Z890 Arctic motherboard. The configuration included 32 GB of TEAMGROUP T-FORCE XTREEM DDR5-7600 memory and an AORUS GeForce RTX 4080 SUPER MASTER graphics card. Cooling was handled by a TRYX Panorama SE 360 mm liquid cooler mounted at the top, assisted by side and bottom intake fans along with a single 120 mm exhaust at the rear. This setup provided a clear airflow path from bottom to top.
CPU Thermals
During AIDA64 stress testing, the Core Ultra 7 265K recorded an average temperature of 71°C, with maximum spikes reaching 75°C. The large radiator at the top, combined with the fan layout, kept the processor stable under load. No thermal throttling occurred, and boost clocks were maintained throughout extended testing.
GPU and Gaming Thermals
The RTX 4080 SUPER MASTER was stressed with FurMark to evaluate sustained performance. The GPU leveled at 67°C under full load, aided by the bottom intake fans that direct airflow toward the card. Core frequencies held steady during prolonged testing, confirming stable thermal behavior.
A long-duration session of Cyberpunk 2077 at 4K resolution with ray tracing enabled was used to simulate a real-world workload. The CPU remained between 60–65°C, while the GPU operated at 64–66°C during gameplay. The system delivered consistent performance without throttling or instability across several hours of testing.
Noise Levels
Noise output was measured 50 cm from the front panel. At idle, the system registered 33 dBA, while combined CPU and GPU load raised levels to 42 dBA. The sound profile remained even, with no vibrations or irregular fan noise due to the rigid aluminum frame and dampened panel fittings.
| Test Scenario | CPU Temp (°C) | GPU Temp (°C) | Noise Level (dBA) |
|---|---|---|---|
| Idle (Desktop) | 36 | 37 | 33 |
| AIDA64 CPU Stress | 71 (peak 75) | – | 39 |
| FurMark GPU Stress | – | 67 | 41 |
| Cyberpunk 2077 (4K, RT ON) | 60–65 | 64–66 | 42 |
Thermal and acoustic testing show that the Jonsbo BO400 provides effective cooling for high-performance hardware. The case maintained stable temperatures for both CPU and GPU workloads, while noise levels stayed within a reasonable range. Its airflow options and modular panel design allow it to accommodate both demanding gaming setups and professional systems.
Mesh vs. Glass Cooling Configuration Impact
| Panel Setup | CPU Temp (°C, AIDA64) | GPU Temp (°C, FurMark) | Noise Level (dBA) |
|---|---|---|---|
| Default (Mesh Top + Glass Side/Front) | 71 (peak 75) | 67 | 42 |
| Full Glass (Top + Side + Front) | 75 (peak 79) | 71 | 41 |
| Mesh Priority (Mesh Top + Mesh Front) | 69 (peak 72) | 65 | 43 |
Here are the separate graphs for the Cooling Configuration Impact — showing CPU temps, GPU temps, and Noise levels across the three panel setups (Default, Full Glass, and Mesh Priority).
The comparison highlights the flexibility of the BO400’s modular design. Users who prioritize appearance can opt for a full-glass layout, though this comes with a small thermal penalty. For performance-oriented builds, the mesh-heavy setup provides the lowest CPU and GPU temperatures, ensuring better headroom under sustained load. The default mixed configuration offers a practical balance, combining strong cooling with a clear view of the hardware.
