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The Corsair Obsidian 900D is a legacy super tower for unusually large builds, not a sensible default for an ordinary gaming PC. Its defining advantages are space for up to 15 internal 3.5-inch drives, five radiator mounting positions, 15 fan locations, ten expansion slots, support for large motherboard formats, and room for two power supplies. The trade-offs are equally concrete: a 41-pound chassis measuring more than 27 inches tall, awkward power-cable routing in some layouts, no dedicated PCIe-slot cooling fan, and optional cages required to reach the maximum drive count.
StorageReview’s April 2013 review reported a street price near $350 and a two-year warranty at launch. Those figures are historical; they do not establish today’s used price, stock, condition, warranty coverage, or availability of replacement cages. Treat the 900D as a specialist case whose value depends on whether you will actually use its storage, radiator, and expansion capacity.
What the Corsair Obsidian 900D is designed to do
The 900D was built around expansion headroom. It accepts ATX, E-ATX, HPTX, Micro ATX, and Mini-ITX motherboards, so the internal volume can accommodate workstation-oriented boards as well as mainstream systems. Ten expansion slots leave room for multiple graphics, storage, networking, or accelerator cards, while two bottom-mounted power-supply positions support redundant or unusually power-hungry configurations.
Quick wins for a faster PC:
Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →That capacity is useful when a system combines a large number of hard drives, several PCIe cards, and custom liquid cooling. It is excessive when the build has one graphics card, one or two drives, a conventional air cooler, and no plans to expand. The case’s physical size affects where it can stand, how it can be transported, and how much time cable management takes, so those factors should be part of the purchase decision rather than afterthoughts.
#1 Best Overall
- Read Before You Buy — No Video Output: These adapters support charging and USB 2.0 data transfer, but cannot transmit video signals. Except for standard USB webcams (which use USB data only), they are not compatible with HDMI/DisplayPort cables, video-capable USB-C hubs, or docking stations with video output.
- Convert USB-A Ports to USB-C: Designed to connect USB-C earphones, cables, flash drives, card readers, and other USB-C accessories to standard USB-A ports. Plug-and-play with no drivers or software required.
- Aluminum Alloy Housing: Built with a sturdy aluminum alloy shell that aids in heat dissipation and protects against daily wear and scratches. Designed to maintain a stable and secure connection.
- Compact & Travel-Friendly: The ultra-compact design allows the adapter to stay plugged into your device without blocking adjacent ports or adding bulk, reducing wear and tear on your original USB ports.
- 12-Month Warranty: Backed by a 12-month manufacturer warranty for peace of mind. Designed to meet strict quality control standards for reliable everyday performance.
Specifications at a glance
The following figures are the manufacturer specifications reproduced in StorageReview’s 2013 review. They describe the design at launch and are not a present-day remeasurement.
| Specification | 900D capability |
|---|---|
| Case class | Full tower / super-tower format |
| Dimensions | 25.6 × 9.9 × 27.2 inches |
| Weight | 41 pounds |
| Motherboards | ATX, E-ATX, HPTX, Micro ATX, Mini-ITX |
| Internal 3.5-inch bays | 9 included, including 3 hot-swap bays; up to 15 with two optional cages |
| External 5.25-inch bays | 4 |
| Expansion slots | 10 |
| Fan mounting locations | Up to 15 |
| Included fans | 4: three 120 mm front fans and one 140 mm rear exhaust |
| Power-supply support | Up to two bottom-mounted PSUs |
| Front I/O | Four USB 2.0 ports, two USB 3.0 ports, and audio ports |
| Construction details | Brushed-aluminum front fascia, cast-aluminum surround structure, and a side window |
How much storage fits
Included drive capacity
There are nine internal 3.5-inch positions in the baseline configuration. Three are hot-swap bays, which can make drive replacement more convenient when the rest of the system is configured for hot swapping. The other included positions still provide substantial capacity for hard disks or compatible 3.5-inch devices, but they do not turn the entire enclosure into a hot-swap backplane.
Fifteen-drive expansion
StorageReview lists expansion to 15 internal 3.5-inch bays when two additional drive cages are installed. Those cages were separate purchases, so a 900D advertised as “15-drive capable” may not actually contain the parts needed to achieve that number. For a used purchase, confirm that both cages, their trays, screws, and any required backplane or cable hardware are present. Replacement-part identity and current stock were not established in the 2013 material.
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1Scan for outdated or missing drivers - takes under a minute2Clear out junk files and repair common Windows errors3Fix the driver behind crashes, sound loss and screen glitchesUsing the 5.25-inch bays
Four external 5.25-inch bays support optical drives, fan controllers, hot-swap modules, or adapters. StorageReview used four Icy Dock ToughArmor MB996SP-6SB six-in-one 2.5-inch-to-5.25-inch adapters in its particular build. That example demonstrates one way to repurpose the bays; it is not a guarantee that every adapter, motherboard, radiator, or cable arrangement will fit together without checking clearances.
Rank #2
- 5-in-1 USB-C Hub: Experience comprehensive connectivity featuring a Power Delivery input, two USB-A 2.0 ports, a USB-A 3.0 port, and an HDMI port. (Note: The USB-C power delivery input port is only for connecting an external wall charger to power your laptop and cannot power peripheral devices.)
- 90W Pass-Through Charging: Achieve optimal charging with 90W pass-through power to your laptop, supported by a total input of 100W, with the hub reserving 10W for operational efficiency. (Note: Wall charger not included.)
- Quick Data Transfers: Accelerate your productivity with rapid data transfers using a high-speed 5Gbps USB 3.0 port and two 480Mbps USB 2.0 ports.
- 4K HDMI Display: Enhance your visual experience with a hub capable of delivering 4K resolution at 30Hz in both mirror and extend modes. Please note that this hub is compatible with MacBook (macOS 12 and newer), Windows 10 and 11, ChromeOS, and laptops equipped with DP Alt Mode and Power Delivery. Note: This device is not compatible with Linux.
- What You Get: Anker USB-C Hub (5-in-1, 4K HDMI), welcome guide, 18-month warranty, and our friendly customer service.
Cooling and radiator options
The review identifies five radiator mounting positions. Their published limits are:
| Position | Published radiator support | Important planning note |
|---|---|---|
| Front | Up to 360 mm | Check drive-cage and reservoir clearance. |
| Top | Up to 480 mm with four 120 mm fans, or 420 mm with three 140 mm fans | Verify motherboard heatsink and memory clearance. |
| Bottom, one side | Up to 480 mm or 420 mm | Bottom hardware can compete with PSU and expansion-card space. |
| Bottom, other side | Up to 280 mm or 240 mm when a PSU is installed | The second-PSU arrangement changes the available radiator length. |
| Rear | 120 mm or 140 mm | Usually competes with the rear exhaust position. |
These are compatibility specifications, not a promise that every listed radiator can be installed simultaneously with every drive cage, fan, pump, reservoir, graphics card, and power supply. Before buying components, draw the intended loop or airflow layout and check radiator thickness, fan thickness, tubing bends, and access to motherboard connectors.
Fifteen fan mounting locations provide considerable airflow flexibility, but the case ships with four fans rather than fifteen. Budget for additional fans and for the headers, splitters, or controller needed to run them. The 900D’s large volume also means that an empty enclosure can have more airflow than a small build needs; adding fans only makes sense when component heat, radiator resistance, or drive density justifies them.
The main advantages
Exceptional storage ceiling
Few cases offer nine included internal 3.5-inch bays, three hot-swap positions, four external 5.25-inch bays, and a path to fifteen internal drives. That combination suits file servers, editing workstations, archival systems, and custom builds that must retain many disks without immediately moving to a rack chassis.
Rank #3
- Sleek 7-in-1 USB-C Hub: Features an HDMI port, two USB-A 3.0 ports, and a USB-C data port, each providing 5Gbps transfer speeds. It also includes a USB-C PD input port for charging up to 100W and dual SD and TF card slots, all in a compact design.
- Flawless 4K@60Hz Video with HDMI: Delivers exceptional clarity and smoothness with its 4K@60Hz HDMI port, making it ideal for high-definition presentations and entertainment. (Note: Only the HDMI port supports video projection; the USB-C port is for data transfer only.)
- Double Up on Efficiency: The two USB-A 3.0 ports and a USB-C port support a fast 5Gbps data rate, significantly boosting your transfer speeds and improving productivity.
- Fast and Reliable 85W Charging: Offers high-capacity, speedy charging for laptops up to 85W, so you spend less time tethered to an outlet and more time being productive.
- What You Get: Anker USB-C Hub (7-in-1), welcome guide, 18-month warranty, and our friendly customer service.
Room for complex liquid cooling
The 480 mm top and bottom radiator locations give a builder options that ordinary full towers do not. Separate radiator zones can help isolate CPU and graphics-card loops or provide generous surface area for a high-wattage workstation. The front, rear, and smaller bottom positions add alternatives when one large radiator is blocked by storage or a power supply.
Broad motherboard and card support
Support for HPTX and E-ATX, alongside ATX and smaller formats, makes the interior viable for oversized workstation boards. Ten expansion slots are useful for multi-card layouts and for cards that occupy more than one slot, although physical spacing and motherboard layout still determine what can be installed together.
Two-PSU capability
Two bottom-mounted power supplies can separate storage and accessory loads from a primary system load or support a specialized workstation. This is a niche feature: it adds cabling, heat sources, and installation complexity, and it should be used only when the electrical design genuinely requires it.
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Legacy external-bay flexibility
The four 5.25-inch bays are increasingly uncommon. They remain useful for optical media, removable-drive modules, monitoring panels, and multi-drive adapters, particularly in systems that need frequent physical access to media.
Rank #4
- Dual Converters, Infinite Potential：Includes 2× USB C male to USB A female adapters and 2× USB A male to USB C female adapters. Perfect for a wide range of uses—tablets with Bluetooth keyboards, expand USB ports on macbook, and more. Two different converters for all your daily needs
- Next-Level 10Gbps & 3A Charging: No more slow 480Mbps, this usb to usb c adapter has a transfer speed of up to 10Gbps, allowing you to do more transferring in less time. This usb adapter fits both USB A and USB C charger, supporting up to 3A fast charging
- Upgraded Exquisite Craftsmanship: With an aluminum alloy housing and metal connector, the usbc to usb adapter is extremely durable and sturdy. Rigorously tested to withstand more than 10,000 times of plugging and unplugging, ensuring long-lasting performance
- Broad Compatible: The usb c to usb adapter widely supports all USB C/ USB A devices like laptops, tablets, cellphones, car chargers, and phone chargers. Such as compatible with MacBook Pro/Air 2023/2022, Thunderbolt 4/3 Devices,Apple MagSafe Watch 9/8/7/SE/Ultra, iPad Pro 2022/2021, Samsung Galaxy S23/S20/S10, and iPhone 17/16/15 Pro. Plug and play
- Please Note: To reach 10Gbps speed, keep the cable under 3.3 ft. For USB A Male to USB C adapters, try flipping the USB C connector. USB C Male to USB A adapters support bidirectional 10Gbps transfer within 3.3 ft
The main disadvantages
Physical scale and handling
At 25.6 inches tall, 27.2 inches deep, 9.9 inches wide, and 41 pounds before components are installed, the 900D needs a strong, spacious location. Measure desk height, shelf depth, doorway clearance, and the path to the work area. Once populated with multiple disks, radiators, coolant, and two PSUs, moving it becomes substantially harder than moving a normal tower.
Power routing can be awkward
In StorageReview’s build, some routes to the 5.25-inch and 3.5-inch bays lacked sufficient power-supply cable length. Without extensions, cables crossed the interior instead of following a clean rear-channel path. This is a documented experience with that layout, not a universal failure for every modular PSU, but buyers should check connector locations and cable lengths before final assembly. Extensions or custom-length cables may be necessary.
No dedicated PCIe-slot cooling fan
The review notes that the case has no PCIe-slot cooling-fan bracket. Dense storage controllers, accelerators, and multi-card arrangements can create heat pockets even when front-to-rear airflow is strong. If your cards run hot, plan a directed fan mount or a different airflow solution rather than assuming the expansion area receives dedicated cooling.
The Tool Desk
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The 15-drive figure depends on two separately sourced cages. Missing cages, trays, or backplane hardware can turn a bargain listing into an incomplete project. The same caution applies to used systems whose front I/O, hot-swap connectors, or fan mounts have been modified.
Best Value
- 5-in-1 Connectivity: Equipped with a 4K HDMI port, a 5 Gbps USB-C data port, two 5 Gbps USB-A ports, and a USB C 100W PD-IN port. Note: The USB C 100W PD-IN port supports only charging and does not support data transfer devices such as headphones or speakers.
- Powerful Pass-Through Charging: Supports up to 85W pass-through charging so you can power up your laptop while you use the hub. Note: Pass-through charging requires a charger (not included). Note: To achieve full power for iPad, we recommend using a 45W wall charger.
- Transfer Files in Seconds: Move files to and from your laptop at speeds of up to 5 Gbps via the USB-C and USB-A data ports. Note: The USB C 5Gbps Data port does not support video output.
- HD Display: Connect to the HDMI port to stream or mirror content to an external monitor in resolutions of up to 4K@30Hz. Note: The USB-C ports do not support video output.
- What You Get: Anker 332 USB-C Hub (5-in-1), welcome guide, our worry-free 18-month warranty, and friendly customer service.
Older connectivity and design assumptions
The front panel provides four USB 2.0 ports and two USB 3.0 ports. That is functional for a legacy system but lacks newer front-panel standards. A current motherboard may require an adapter or leave some ports unused, and a used case may have damaged cables or connectors after years of handling.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Building in the 900D: a practical planning sequence
- Measure the installation site. Allow clearance above, behind, and beside the case for ventilation and cable access. Include the 41-pound empty chassis in your handling plan.
- Inventory the exact case. Count the nine base drive positions, identify the three hot-swap bays, check whether both optional cages are included, and inspect every tray and backplane connector.
- Map motherboard and card positions. Confirm the board form factor, slot spacing, GPU length, card thickness, and whether ten slots are usable with your chosen board.
- Choose radiators before filling drive bays. Mark the top, front, and bottom radiator footprints, then check memory, heatsink, PSU, pump, reservoir, and drive-cage conflicts.
- Plan power cables on paper. Measure the distance to 5.25-inch and 3.5-inch devices. Keep extensions or alternate-length modular cables available if the PSU leads cannot reach behind the motherboard tray.
- Design PCIe airflow. If storage cards or accelerators occupy several slots, reserve a directed intake or side-mounted solution because there is no dedicated PCIe cooling fan.
- Populate and test incrementally. Install the motherboard and power supply first, then test fans and front I/O before filling every bay. This leaves access for troubleshooting.
Who should buy one
Good matches
- A storage-heavy workstation or home server that can use nine or more internal 3.5-inch drives.
- A custom liquid-cooled system requiring a 480 mm radiator or multiple radiator zones.
- A build using HPTX or E-ATX hardware, many PCIe cards, or two power supplies.
- A user who specifically needs several external 5.25-inch bays for removable storage or optical hardware.
Poor matches
- A conventional gaming PC with one graphics card and a small number of SSDs.
- A compact office or living-room installation where height, depth, or weight is constrained.
- A buyer unwilling to source optional cages, cable extensions, replacement trays, or extra fans.
- A build whose only reason for choosing the case is appearance rather than usable capacity.
Is the Corsair Obsidian 900D worth buying used?
There is no reliable current price, stock, condition, or warranty figure established by the 2013 reviews. StorageReview’s near-$350 street price and two-year warranty describe the launch period only. Evaluate each listing on its own evidence rather than treating those historical numbers as a current valuation.
Used-case inspection checklist
- Verify the exact 900D model and inspect for bent panels, corrosion, damaged glass or side-window hardware, and missing screws.
- Confirm all nine standard 3.5-inch positions and the three hot-swap bays are present and physically intact.
- Ask whether both optional cages and their trays are included if the seller claims 15-drive capacity.
- Test or photograph the four USB 2.0 ports, two USB 3.0 ports, audio connectors, power switch, and indicator wiring.
- Check that the included three front 120 mm fans and one rear 140 mm fan are present, or price replacements.
- Inspect radiator mounts for stripped threads and verify that bottom mounts are not blocked by modifications.
- Request clear return terms. A large case can be expensive to ship back, so undisclosed missing accessories matter.
How to compare the 900D with another case
Do not compare only exterior volume or a maximum radiator number. Use the following questions for both cases:
| Comparison point | What to verify |
|---|---|
| Drive capacity | Usable internal 3.5-inch count, hot-swap count, included cages, trays, and backplanes |
| Cooling | Radiator size and thickness at each position, with drives and PSUs installed |
| Expansion | Motherboard formats, slot count, card spacing, and GPU length |
| Power | One- or two-PSU support and cable length to remote bays |
| Airflow | Included fans, available mounts, dust filtering, and cooling around PCIe cards |
| Usability | Front I/O generation, access to trays, cable-routing paths, and service clearance |
| Purchase risk | Asking price, physical condition, missing accessories, seller return terms, and shipping cost |
Bottom line: the 900D’s real pros and cons
The Corsair Obsidian 900D remains compelling when its unusual capacity solves a real problem: up to 15 internal 3.5-inch drives with optional cages, multiple large radiators, broad motherboard support, ten expansion slots, legacy 5.25-inch flexibility, and two-PSU capability. Those strengths make it a practical platform for storage-heavy or custom-cooled workstations.
Its drawbacks are not minor details. The 41-pound, more-than-27-inch-tall chassis demands space; some power routes may require extensions; PCIe cards lack a dedicated cooling fan; and the maximum drive count depends on parts that may be missing from a used listing. Buy it when you can name the bays, radiator positions, or expansion slots you will use and have verified the specific unit’s accessories. For a simpler build, a smaller modern case is usually the more convenient choice.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
