Obsidian Three | RTX 5090 32GB + Ryzen 7 9800X3D | Ready-to-Go Gaming PC | PC36

💎 Obsidian Three

A 5090 you are meant to look at

Obsidian Three is the fastest machine we build in a micro-ATX case. An RTX 5090, a Ryzen 7 9800X3D, 48GB of memory and a 360mm liquid cooler, all sitting behind two panes of tempered glass with the entire cable loom hidden in the chamber behind.

The 5090 is the fastest consumer graphics card in the world and it is also the largest and the most awkward. Most cases that take one comfortably are full towers. This one is not, and getting a card of that size and weight into a 54 litre dual chamber case, cooled properly and cabled so the glass side still looks deliberate, is most of what this build is.

Nothing here is power limited and nothing is undervolted. This is a compact case, not a tiny one, and there is enough air in it to let both parts run as they were designed to.

🧬 Built to last, designed to evolve

This system is built on AMD's latest AM5 platform, which offers one of the best upgrade paths available today. That means you can start with a great processor now and still have room to move up the stack later, while keeping the same motherboard, case, power supply and most of your core components. In practice this machine is already at the top of what AM5 offers for gaming, so what the platform really buys you is the freedom to change the graphics card in a few years without touching anything else.

📃 Specifications

• 🧠 CPU: AMD Ryzen 7 9800X3D
  Click or tap for deeper spec info

  • 8 cores, 16 threads of Zen 5 with 96MB of L3 cache, using second-generation 3D V-Cache mounted underneath the cores rather than on top of them
  • AMD's flagship gaming processor. In any title that is even slightly CPU-sensitive that stacked cache shows up in the frame times rather than just the marketing
  • The cache position matters more than it sounds. On the 7800X3D the cache sat above the cores, which trapped heat and forced AMD to lock the multiplier. Moving it underneath solved both problems, so unlike its predecessor this chip is fully unlocked and genuinely overclocks. That is why Ultimate Performance Tune means something on this listing and does not on Obsidian Two
  • Running to its full stock power limits here. There is no cap and no restriction, which is worth saying because that is not true of every compact machine at this performance level
  • Paired with a 5090, this is a processor that will not be the limiting factor at 1440p or 4K for a very long time
• ❄️ CPU cooler: Thermalright Aqua Elite V5 360mm ARGB liquid cooler
  Click or tap for deeper spec info

  • A 360mm all-in-one liquid cooler with three 120mm ARGB PWM fans, mounted in the roof of the case as exhaust
  • Top mounted, and that is Corsair's own instruction rather than our preference. The 2500X will physically take a radiator in the base, but Corsair specifically advise against it: it causes premature pump wear, worse thermals and more noise, because air collects at the pump rather than at the highest point of the loop. We follow that
  • 360mm rather than the 240mm used on Obsidian Two, because a 9800X3D running unrestricted alongside a 575W graphics card asks considerably more of the cooling than a 7800X3D does. The extra radiator area is what lets the fans stay slow
  • The front of this case is glass, so there is no front radiator position at all. The roof is the only sensible home for a 360 in a 2500X, and it takes one properly
  • Liquid cooling adds real assembly time compared with a tower cooler, and a 360 in a dual chamber micro-ATX case more so, because the tubing has to be routed without ever crossing the glass. That work is included in the price rather than added to it
• 🔲 Motherboard: Sapphire NITRO+ B850M WiFi (micro-ATX)
  Click or tap for deeper spec info

  • 12+2+1 phase power design at 55A per stage, fed by two 8-pin CPU connectors rather than the usual one. Plain English translation: this is the strongest power delivery in our micro-ATX range, and it is what makes an unrestricted 9800X3D with an overclock a sensible thing to offer here
  • PCIe 5.0 x16 for the graphics card. Worth stating plainly, because Gen5 graphics slots are optional on the B850 chipset and plenty of boards only give you Gen4. We specify a Gen5 slot on every 5080 and 5090 build we sell
  • Two M.2 slots, the first PCIe Gen5 x4 and the second Gen4 x4, so one stays free for a drive you add later. Four SATA ports as well
  • Four DDR5 slots supporting up to 192GB, two of them free on this build
  • Wi-Fi 6, Bluetooth 5.3 and 2.5 Gigabit Ethernet. Wi-Fi 6 is quick and stable, and on a machine like this we would use the wired port anyway. If you want Wi-Fi 7, see the X870 upgrade below
  • Realtek ALC897 audio, which is the standard codec at this board size. Fine for a USB or wireless headset, since those bypass it entirely. If you use wired 3.5mm headphones and care about it, the X870 upgrade below is the answer and we explain exactly what it changes
  • Three addressable RGB headers and one standard RGB header, which is what drives the lighting in this build
  • PC36 only uses motherboards chosen for stability and longevity. See our Trusted brands page
• 📏 Memory / RAM: 48GB (2×24GB) DDR5-6000 CL36 or better
  Click or tap for deeper spec info

  • EXPO-tuned dual channel DDR5-6000 CL36, the speed and timing combination Ryzen responds to best on AM5. Two sticks rather than four, so the memory controller runs at its rated speed
  • 48GB rather than 32GB because at this tier the extra capacity is small relative to the build and it removes the one bottleneck that is genuinely annoying to fix later. It is the capacity we fit on every 5090 machine
  • Worth being specific about the "or better": depending on stock we may fit a higher-binned kit and tune it down to 6000 CL36 or tighter. You get the better silicon at no extra cost, and the specification quoted is the floor rather than the target
  • Two slots stay free, so this can be taken further later without discarding the kit
  • Specification guaranteed, model may vary. Happy to confirm the exact part on request
• 💾 Storage: 1TB NVMe PCIe 4.0 SSD (TLC)
  Click or tap for deeper spec info

  • TLC flash rated at 6,500MB/s or better, which holds its speed through long sustained writes rather than dropping off once a cache fills
  • High write endurance, which matters on a machine likely to be used for 4K capture or video editing as well as games
  • We fit 1TB as standard across the whole range rather than varying it by price, so comparing our machines to each other is straightforward. On this build in particular we would encourage you to take the 2TB option, and we have said so plainly in the upgrades below rather than quietly leaving it as an upsell
  • One further M.2 slot sits free, and the rear chamber takes two 2.5 inch and two 3.5 inch drives
  • Specification guaranteed, model may vary. Happy to confirm the exact part on request
• 🎮 Graphics card: NVIDIA RTX 5090 32GB (shipped separately for safety, see below)
  Click or tap for deeper spec info

  • This is a bulky and valuable graphics card, and as such it will be shipped separately with instructions for you to install it upon receipt
  • To be clear about what that means: the card is fitted into this exact system, stress tested in it, and only then carefully removed and boxed for transit. Your machine is built and validated as a whole. We do not drop-ship graphics cards or send you parts to assemble
  • The fastest consumer graphics card in the world. 4K at maximum settings with path tracing and DLSS 4 multi frame generation, and 32GB of GDDR7 on a 512-bit bus that does work in 3D, AI and video applications no other consumer card can
  • NVENC for streaming and recording, with the encoder capacity to do it while playing without touching your frame rate
  • Around 575W under load. That is the largest single number in this build and it is why the power supply, the cooler and the fan layout are what they are
  • The case takes cards up to 400mm long, so length is not a constraint here. Thickness is the thing to watch in a four-slot opening, and we source cards that fit it properly rather than ones that only just go in
  • The chipset and VRAM are guaranteed: it will always be an RTX 5090 with 32GB. The AIB brand varies with availability, and we only use established manufacturers. See our Trusted brands page for more info
• 🧰 Case: Corsair 2500X, Black
  Click or tap for deeper spec info

  • 376 × 469 × 304mm, roughly 54 litres. Micro-ATX, with four expansion slots
  • Dual chamber. The left side, behind the glass, holds the motherboard, processor, cooler and graphics card. The right side, behind a mesh panel, holds the power supply, the drives and every cable. The two are separated by the motherboard tray
  • Tempered glass on the front and the left side, lightly smoke tinted. Mesh on the right, with a dust filter over the power supply intake
  • Around 100mm of space behind the motherboard tray, which is exceptional for a case this size. On this build it is not a luxury, it is what makes a 1000W loom and a 12V-2x6 cable disappear
  • Graphics cards up to 400mm, CPU coolers up to 180mm, power supplies up to 225mm. The case ships with an SFX bracket fitted, which we remove to take a full size ATX supply
  • Radiators up to 360mm in the roof and the base, 240mm in the side position, 120mm at the rear. None at the front, because the front is glass
  • Two 3.5 inch and two 2.5 inch drive mounts in the rear chamber, and support for rear-connector motherboards if you ever want one
• 🌬️ Case cooling: 2 × 120mm ARGB reverse-blade side intake plus 1 × 120mm ARGB rear exhaust, fitted by us, alongside the cooler's 3 × 120mm roof exhaust
  Click or tap for deeper spec info

  • The 2500X ships with no fans at all. Not a reduced set, none. Every fan in this machine is one we have chosen and fitted
  • Reverse-blade fans on the intakes. A normal fan shows you its frame and its wiring from the front. A reverse-blade fan is built the other way round, so the blade face is what you see through the glass. With two glass panels that is the difference between looking finished and looking assembled, and it costs us no more than a standard fan
  • Two intakes in the side position feeding cool air straight alongside the graphics card, one exhaust at the rear, and the 360mm radiator exhausting through the roof. Six fans in total
  • The bottom mounts are left empty on purpose. Fans will physically fit down there, but in this chassis they sit so close to the underside of the graphics card that they have very little room to breathe and contribute much less than the mount count suggests. We would rather fit fans where they work than where they look busy. If you want them anyway, slim fans are the right answer and we can fit them, see the upgrade options
  • Worth knowing what fans are actually worth here: independent testing of this case found that adding fans was worth around 7°C on processor temperatures, while removing the glass panels entirely was worth about 1°C. The glass is not what limits this case
  • Fan and pump curves are set by hand before dispatch and verified through our standard stress testing rather than assumed
  • Being straight about noise: this is a 575W graphics card in a 54 litre case. At idle and in lighter games it is quiet. Under sustained heavy load you will hear it, and that is true of any 5090 anywhere. What the cooling here buys you is a machine that holds its clocks rather than one that is silent
• ⚡ Power supply: Corsair RM1000e 1000W 80+ Gold, fully modular
  Click or tap for deeper spec info

  • 1000W is NVIDIA's recommended figure for the RTX 5090, and this is a Corsair RM-series unit rather than the cheapest thing that carries the number
  • Native 12V-2x6 connector with Corsair's ThermalProtect sensing built into the connector itself, which monitors the connection and shuts things down before a poor seat becomes a problem. On a 575W card drawing through a single connector, that is a feature worth having rather than a marketing line
  • ATX 3.1 certified, built to absorb the brief power spikes a 5090 produces rather than tripping over them
  • Fully modular, so only the cables this build uses are installed. With a 1000W loom in a dual chamber case, every cable not fitted is one less thing to hide
  • Corsair back it with a long manufacturer warranty and it is a genuinely quiet unit at the loads this build produces
• 🔌 Cabling: Black cabling, routed into the rear chamber
  Click or tap for deeper spec info

  • Black cables throughout, routed through the tray's grommets into the right-hand chamber and tied down there, so the glass side shows components and nothing else
  • This is the hardest cable job in our micro-ATX range. A 1000W modular loom, a 12V-2x6 card cable, six fans and a pump header all have to end up somewhere that is not visible through two panes of glass. It is where a large share of the assembly time on this build goes
  • Braided cable extensions in a colour of your choice are available, and on this listing more than any other they are worth considering. See the upgrade options below
• 📶 WiFi / Bluetooth / Ethernet: Wi-Fi 6, Bluetooth 5.3 and 2.5 Gigabit Ethernet, included
  Click or tap for deeper spec info

  • Built into the Sapphire NITRO+ B850M WiFi. No separate adapter needed, and the aerial is supplied in the box
  • Wi-Fi 6 is fast and stable, and comfortably ahead of any UK domestic broadband connection. It is plenty for downloads, 4K streaming and online play
  • 2.5 Gigabit wired Ethernet, which is what we would recommend using on a machine like this regardless of the wireless
  • If you specifically want Wi-Fi 7, the X870 motherboard upgrade in the options below covers it, along with USB4
• 🪟 Operating system: As chosen by you from the listing options below. Windows 11 Home (OEM) is recommended.
• 🧹 Setup and optimisation: PC36 High-Class Standard. Full stress test with certificate, bloat-free installation, and BIOS set up properly
  Click or tap for deeper spec info

  PC36 High-Class Standard, included free with every build

  • Ready the moment you open the box. Your PC boots straight into Windows with a local account already set up. No account sign-in wall, no first-run questionnaire, no half-hour of setup before you can use the machine you just bought
  • BIOS updated and configured properly: manual fan curves, PBO enabled, EXPO enabled, Secure Boot enabled
  • Vanilla Windows 11 installation if you choose Windows, with no bloatware added by us, and all drivers loaded and ready to go
  • Full stress test with certificate. Every system is torture tested on CPU, RAM and GPU before dispatch, and ships with the certificate to prove it. On a build with a 5090 in it, that testing is the part that matters most

  PC36 Premier Optimisation, available in the listing options

  • CPU tuning to bring thermals and noise down with minimal performance loss, plus a deeper strip and debloat of Windows and a hand-tuned fan and pump profile
  • The best value option on this listing. A 9800X3D responds very well to a per-core Curve Optimiser undervolt, and on a liquid cooled machine the pump curve matters as much as the fans. Left at defaults, most AIOs run the pump far harder than they need to, and in a case with this much glass the noise has nowhere to go but out of the back

  PC36 Ultimate Performance Tune, available in the listing options

  • Advanced overclocking: memory tune, CPU tune and GPU overclock on top of everything in Premier
  • Unlike the 7800X3D in Obsidian Two, the 9800X3D is genuinely unlocked, so the CPU portion here is a real overclock rather than an undervolt. Combined with a memory tune and a GPU overclock there is measurable performance in it, and the 12+2+1 board, the 360mm cooler and the 1000W supply all have the headroom to support it. This is one of the listings where Ultimate earns its money
• 🛡️ Warranty: 3 years parts & labour (return to base)
  Click or tap for deeper spec info

  • Standard 3-year coverage included, parts and labour both
  • Optional extended warranties in the listing options below

👁️ Transparency notes

• The graphics card ships in its own box to protect the PCIe connector in transit, with instructions for fitting it (click or tap to read more)

  This PC contains a large and high value graphics card. All graphics cards have a point of weakness at the PCIe connector, and shipping the card in its own box prevents damage that can happen in transit despite our industry-leading packaging. It arrives with simple instructions and fitting it takes a couple of minutes. If you have any queries about this, please contact us. This is without doubt the safest method to ensuring your high performance graphics card arrives pristine.

• Our photographs show the walnut version of this case, but every build now uses the plain black one, which is otherwise identical (click or tap to read more)

  Corsair sell the 2500X with an optional walnut front and roof, and that is what is in our gallery. It is no longer something we can source reliably, so every Obsidian we build now uses the standard black case, which is otherwise identical in every dimension and every feature. We are photographing a black build and the images will be replaced. Until then, look at the black case rather than the wood when you picture yours. If the woodgrain is specifically what you wanted, talk to us on live chat before you order and we will tell you honestly whether we can get one.

• The glass is smoke tinted, which looks superb in a lit room and dims the interior in a dark one (click or tap to read more)

  Worth knowing before you order if you want the lighting to read strongly at night, because a tinted panel dims what is behind it.

• Product images are representative photos of a similar spec in the same style. Your PC will look similar but not identical. Our support team can help clarify anything you're unsure of.

🛠️ Popular upgrade options

• Quick-add upgrades. This listing has a set of one-click upgrades chosen to fit this exact build, each one priced, in the Quick-add Upgrades section on this page. Memory, storage, optimisation, the anti-sag bracket and the extended warranty are in the build options instead. Anything not shown in either place, ask us on live chat and we will price it.
• X870 motherboard upgrade: available in the listing options below.
  Click or tap for more info

  This swaps the Sapphire for a Gigabyte X870M AORUS ELITE WIFI7. Three things genuinely change, and we would rather list them precisely than sell you a chipset name.

  Wi-Fi 7 instead of Wi-Fi 6. Useful if you already have a Wi-Fi 7 router, and future-proofing if you do not. Two USB4 ports at 40Gbps, which no B850 board has: single-cable docks, very fast external drives, and DisplayPort out over USB-C. And the audio codec moves from ALC897 to ALC1220, which takes the signal-to-noise ratio on the analogue output from around 97dB to around 120dB, with dedicated audio capacitors and PCB isolation. That is a real, measurable drop in the noise floor rather than a marketing claim.

  Now the honest part. The audio improvement only applies to wired 3.5mm headphones and speakers. If you use a USB headset, a wireless headset, HDMI to a TV or receiver, or an external DAC, the motherboard codec is bypassed entirely and you will hear no difference at all. Wi-Fi 7 does nothing without a Wi-Fi 7 router. And it will not give you a single extra frame per second, because the B850 board already feeds the graphics card a full PCIe 5.0 x16 slot from the processor.

  One genuine trade-off to weigh: the Gigabyte has two SATA ports where the Sapphire has four. If you keep several mechanical drives, that matters. If you do not, it never will.

• Storage upgrade to 2TB: available in the listing options below.
  Click or tap for more info

  The one upgrade we would push on this listing. We fit 1TB as standard across the whole range so that our machines can be compared like for like, but on a 5090 build used for 4K capture, 3D or video work a 1TB drive is genuinely tight. Two modern AAA installs and a project folder will fill it. There is one free M.2 slot so it can be added later, but it is cheaper taken now.

• Braided cable extensions: available in the listing options below.
  Click or tap for more info

  Of everything we sell, this is the build where cable extensions make the most difference. Two glass panels, a 5090 and six lit fans means the cabling is genuinely part of what you see. Purely cosmetic, and entirely reasonable to skip, but it is the finishing touch on a machine that is meant to be looked at.

• Three slim 120mm intake fans in the base: available via live chat.
  Click or tap for more info

  We leave the bottom mounts empty as standard because standard-depth fans there sit very close to the underside of the graphics card and achieve less than the mount count implies. Slim fans change that arithmetic: they give a 575W card meaningfully more room to breathe and put cool air directly where most of the heat is made. This is the tier where it is most worth considering, particularly if you intend to overclock the card or the machine will live somewhere warm. Ask us on live chat and we will price it and tell you honestly what it will and will not gain you.

• Memory upgrade to 64GB: available in the listing options below.
  Click or tap for more info

  Worth it if you work with large 3D scenes, long 4K timelines or local AI models alongside the card's 32GB of VRAM. For gaming, 48GB is already well past what any current title asks for, and we would not push you into this on gaming grounds alone.

• Extended warranty: available in the listing options below.
• Anything else: speak with us via live chat. Different fan colours, a white case, a specific card model, a different board. This is our flagship micro-ATX build and we are happy to discuss any part of it before you order.

🎯 What is this PC best for?

• 4K at maximum settings, including path tracing, in anything currently made
• High refresh 1440p, where the 9800X3D's cache sets the ceiling rather than the card
• 3D rendering, local AI work and heavy video timelines, where 32GB of VRAM does work no other consumer card can
• Streaming and recording with NVENC while playing, without touching your frame rate
• Anyone who wants flagship performance in something that fits on a desk rather than beside one
• Buyers who want the machine to be visible, and want what is inside it to look considered

📊 Performance estimates

Figures are given at both 1440p and 4K. Performance varies with game updates, maps, settings and background apps. These are estimates, not guarantees.

Fortnite - Competitive Settings (click or tap to expand)

1440p: 370-460 FPS
4K: 255-325 FPS
Native testing (no upscaling or frame generation).

Cyberpunk 2077 - Ray Tracing Medium (click or tap to expand)

1440p: 170-215 FPS
4K: 122-156 FPS
Upscaling set to Auto (DLSS / FSR / XeSS based on GPU).

Battlefield 6 - High Settings (click or tap to expand)

1440p: 185-230 FPS
4K: 128-162 FPS
Native testing (no upscaling or frame generation).

DaVinci Resolve - PugetBench Standard (click or tap to expand)

Estimated score: 11,500-12,500

💬 Need help?

Not sure if this is the right spec for you? Ping us on live chat and we'll compare it honestly against our tower builds and our small form factor machines, and guide you to the right one. You'll be talking to one of us, not a chatbot.