Metallique Three | RTX 5090 + Ryzen 7 9800X3D + ITX Case | Ready-to-Go Gaming PC | PC36

🩵 Metallique Three

A 5090 in nineteen litres, and an honest account of what that takes

Metallique Three puts an RTX 5090 and a Ryzen 7 9800X3D into a case smaller than most consoles. It is the most demanding build we make, and it is the one where the work we do matters most.

Nothing about this configuration is accidental. The cooler is 53mm tall because that is what the graphics card leaves room for. The processor runs to a power limit we set rather than the one AMD ships. The graphics card is undervolted. Every one of those decisions costs a small amount of peak performance and buys back a machine that holds its clocks all evening instead of throttling after twenty minutes.

We are not going to pretend a compact flagship performs identically to a tower. It does not, and the difference is set out plainly below. What it does instead is fit on a desk, travel in a car, and look like a piece of machined equipment rather than a gaming PC.

🧬 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 this layout Metallique Three is tuned for long-term stability and sensible noise rather than unchecked power draw, so the headroom that exists is used deliberately rather than spent on the last two percent.

📃 Specifications

• 🧠 CPU: AMD Ryzen 7 9800X3D (power limited to approximately 90W, see below)
  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
  • We deliberately limit this processor to around 90W PPT. That is well below its stock ceiling and it is the single most important decision on this listing. In nineteen litres, a 9800X3D allowed to draw whatever it wants will heat-soak the chassis and force every fan in the machine to work harder, including the graphics card's. Capping it costs a small amount of multi-core throughput and almost nothing in games, because the cache rather than raw power is what makes this chip fast
  • Curve Optimiser and thermal limits are set alongside that cap, so the processor holds high boost clocks at a temperature the case can actually sustain
  • If you want a 9800X3D running unrestricted, that is a tower build and we will happily point you at one
• ❄️ CPU cooler: Thermalright AXP90-X53 Full Copper, with a Noctua NF-A9x14 fan and Noctua NT-H2 paste
  Click or tap for deeper spec info

  • 53mm total height. That number is not a preference, it is arithmetic: an RTX 5090 is a thick card, and this case works to a combined budget where graphics card thickness plus cooler height cannot exceed 125mm. A taller cooler simply will not go in alongside this graphics card
  • Full copper construction rather than the usual aluminium fin stack with copper pipes, which moves more heat through a smaller volume. At 53mm there is no space to waste on cheaper materials
  • We replace the supplied fan with a Noctua NF-A9x14 and use Noctua NT-H2 paste. On a cooler this small the fan is doing a disproportionate share of the work, and it is the part you hear
  • Top-down design, so it also pushes air across the motherboard's power stages and memory
  • This cooler and the 90W power limit are a matched pair. Neither would be sufficient without the other, and together they are what makes the build viable
• 🔲 Motherboard: ASRock B850I Lightning WiFi (Mini-ITX)
  Click or tap for deeper spec info

  • 12 phase power design with ten 110A SPS stages on Vcore, around 1,100A available to the processor. Plain English translation: desktop-tower power delivery on a 17cm square board. Since we are running the processor well below its limits, the board is never remotely stressed, which is exactly the margin you want in a machine this dense
  • PCIe 5.0 x16 for the graphics card, which is the interface the RTX 5090 is built for
  • Two M.2 slots, the primary at PCIe Gen5 x4 and the second at Gen4 x4, so one stays free for a drive you add later
  • It ships with a thermistor cable, and on this build we use it. It lets us place a temperature probe where heat actually collects rather than relying on the CPU sensor alone, and drive the fan curve from that measurement. In a chassis with no through-draught, tuning from the right sensor is most of the job
  • Wi-Fi 6E with 160MHz channels, Bluetooth 5.2, and Killer E3100G 2.5 Gigabit Ethernet
  • Realtek ALC1220 audio, a genuine step above the codec normally fitted at this board size
  • Two DDR5 slots, as every Mini-ITX board has. Both are used by the memory fitted
  • 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, particularly on a board with only two slots
  • Worth being specific about the "or better": depending on stock we may fit a higher-binned kit, for example 7600 CL38, and tune it down to 6000 CL36 or tighter. In practice we usually reach 6000 CL30 comfortably. You get the better silicon at no extra cost, and the specification quoted is the floor rather than the target
  • Specification guaranteed, model may vary. Happy to confirm the exact part on request
• 💾 Storage: 1TB NVMe PCIe 4.0 SSD, DRAM-buffered
  Click or tap for deeper spec info

  • A premium drive with its own DRAM cache rather than borrowing system memory, which is what keeps performance consistent under sustained load rather than only in short bursts. Typically a WD SN850X or Samsung 990 Pro
  • Rated at 6,500MB/s or better, with the write endurance to match a machine that may be used for capture or editing as well as games
  • The second M.2 slot sits free, so a drive can be added later. Worth noting the case has one 2.5 inch bay, so M.2 is the sensible expansion route here
  • Specification guaranteed, model may vary. Happy to confirm the exact part on request
• 🎮 Graphics card: NVIDIA RTX 5090 32GB
  Click or tap for deeper spec info

  • The card arrives fitted, because in this chassis it is safer that way. It is mounted vertically on a riser against the side panel and supported along its length rather than cantilevered off the motherboard, so it travels as built. Nothing to install, nothing to unbox and align, no thermal paste to worry about
  • 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
  • Card choice is genuinely restricted in this chassis and we would rather say which ones we use: typically a Gigabyte Windforce or a Zotac Solid. Those are the models whose dimensions leave room for the 53mm cooler beside them. It is not a long list
  • The card is usually undervolted. A 5090 will take 575W if allowed, and in nineteen litres that is more heat than the case can remove indefinitely. Undervolting reduces the heat substantially for a small performance cost, and it is part of what makes this build hold its clocks rather than sawtooth
  • The chipset and VRAM are guaranteed: it will always be an RTX 5090 with 32GB. See our Trusted brands page for more info
• 🧰 Case: Antec Performance 1M - Black
  Click or tap for deeper spec info

  • 19.2 litres, 424mm deep by 175mm wide by 260mm tall. Steel frame with CNC-machined aluminium side panels and rear frame. It is genuinely rigid, which is why we are comfortable saying it travels well
  • Takes graphics cards up to 350mm long. That clearance is the entire reason a 5090 build in this size is possible at all, and it is why we chose this chassis over the more obvious compact options
  • The interior works to a combined budget: graphics card thickness plus CPU cooler height cannot exceed 125mm between them. On this build the card takes the lion's share and the cooler gets 53mm, which is why the parts list reads as it does
  • Tool-free side panels for access, and perforated panelling on both sides directly alongside the components rather than a long duct
  • Small form factor builds take considerably longer to assemble, cable and tune than a standard tower. On this one it takes longer again. That work is included in the price rather than added to it
• 🌬️ Case cooling: 2 × 120mm bottom intake fans
  Click or tap for deeper spec info

  • The Performance 1M ships with no fans. We fit two 120mm intakes in the base, feeding cool outside air directly up into the graphics card, which is where almost all of the heat in this machine is generated
  • Air leaves through the perforated side panels and the rear. In nineteen litres the components sit close to the outside of the case, so the path is short
  • Fan curves are tuned manually before dispatch using the board's thermistor probe as well as the CPU sensor, then verified through our standard stress testing rather than assumed
  • Being straight about expectations: this is a flagship machine in nineteen litres. Under sustained heavy load it is audible, and no amount of tuning changes that. At idle and in lighter games it is genuinely quiet. Anyone who tells you a 5090 can be silent in this volume has not built one
• ⚡ Power supply: Thermaltake Toughpower SFX 1000W 80+ Gold ATX 3.1, fully modular
  Click or tap for deeper spec info

  • 1000W is NVIDIA's recommended figure for the RTX 5090, and it is available here in SFX form factor, which is the only size this case takes
  • An SFX unit at this wattage is a genuinely specialist component and costs considerably more than the equivalent ATX supply. It is one of the larger hidden expenses in a build like this and we would rather explain it than bury it
  • ATX 3.1 certified with a native 12V-2x6 connector, so the card plugs straight in with no adaptor. All PC36 power supplies of 750W and above are ATX 3.1 certified
  • Because both the processor and graphics card are running to limits we set rather than their maximums, the supply spends its life comfortably inside its efficient band rather than near the top of it
  • Fully modular, which in nineteen litres is a functional requirement rather than a tidiness preference
• 🔌 Cabling: Black cabling, routed for a dense chassis
  Click or tap for deeper spec info

  • Short runs, routed specifically to keep the intake path and the card's own fans clear. This is the hardest cable job in our range and it is where a large share of the assembly time goes
  • Fully modular, so nothing unused is installed. In this case there is genuinely nowhere to put a spare cable
• 📶 WiFi / Bluetooth / Ethernet: Wi-Fi 6E, Bluetooth 5.2 and Killer 2.5 Gigabit Ethernet, included
  Click or tap for deeper spec info

  • Built into the ASRock B850I Lightning WiFi. No separate adapter needed, and the aerial is supplied in the box
  • Wi-Fi 6E with 160MHz channel support, which adds the 6GHz band. Usually far less congested than 2.4 and 5GHz if your router supports it
  • Killer E3100G 2.5 Gigabit Ethernet for a wired connection, which we would still recommend for competitive play
• 🪟 Operating system: As chosen by you from the listing options below. Windows 11 Home (OEM) is recommended.
• 🧹 Setup and optimisation: PC36 Premier Optimisation is included in the price on this build. There is no need to add it from the options
  Click or tap for deeper spec info

  Why it is included rather than optional

  • On every other machine we sell, Premier Optimisation is a genuine choice. On this one it is not, because the build does not work without it. The 90W processor limit, the Curve Optimiser tune, the graphics card undervolt and the thermistor-driven fan curves are the reason a 5090 is viable in nineteen litres at all
  • Charging separately for work the machine cannot function properly without would be dishonest, so it is in the price

  Everything in PC36 High-Class Standard is included too

  • 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
  • BIOS updated and configured properly, with the tuning above applied and documented
  • Vanilla Windows 11 installation if you choose Windows, with no bloatware added by us, and all drivers loaded
  • Full stress test with certificate. Every system is torture tested on CPU, RAM and GPU before dispatch. On this build that testing is what proves the tuning holds

  PC36 Ultimate Performance Tune

  • Not offered on this build, and we would decline it if asked. Ultimate exists to push clocks upward. This machine is deliberately tuned in the other direction, because thermal headroom rather than clock ceiling is what limits it. Adding an overclock here would make it slower under sustained load, not faster
• 🛡️ 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

• Expect roughly 1 to 4 percent less than the same parts in a tower, which is what buys sustained performance rather than throttling (click or tap to read more)

  That is the honest cost of the power limits and undervolts described above. We would rather quote you the real figure than a benchmark number this chassis cannot sustain.

• Our tuning lives in the BIOS and in MSI Afterburner, so please talk to us before changing any of it (click or tap to read more)

  Removing or changing those settings will undo our work and can make the machine hotter, louder and slower. We would strongly recommend not modifying them without talking to us first. If something needs changing, ask and we will walk you through it.

• Photos may show a cable tie holding the graphics card, which is deliberate, permanent and routed clear of every fan (click or tap to read more)

  A card the size and weight of a 5090 will sag and sway at its outer end, and in a chassis this dense that movement is a real risk. The restraint prevents it. It is not a bodge, it is how we make this build safe to own and to move.

• Small form factor systems run warmer, so we set a sensible thermal limit in the BIOS that costs nothing you would notice (click or tap to read more)

  The CPU thermal limit is set deliberately, alongside the power cap. It protects the machine and costs nothing you would notice in a game.

• 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

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

  Worth it for most people buying at this level, and the one upgrade on this listing we would recommend without hesitation. Modern AAA installs regularly run past 150GB each, and if you are capturing at 4K the 1TB drive fills quickly. The second M.2 slot is free either way, so it can also be added later.

• A larger case: available via live chat.
  Click or tap for more info

  Worth saying plainly, because it is the honest recommendation for a lot of people who land on this page. If you can accommodate something slightly bigger, a Lian Li A3 or a micro-ATX chassis gives this same hardware considerably more thermal room, which means no power limits, no undervolt, and a quieter machine for the same money. Metallique Three exists for people who genuinely need this footprint. If you do not, tell us and we will build you the better-performing version.

• A Ryzen 9 processor: available via live chat.
  Click or tap for more info

  Possible, but it is not an upgrade we would encourage. A Ryzen 9 in this chassis has to be restricted further than the 9800X3D already is, so it gives up more of its advantage than it keeps. In games the 9800X3D is the faster chip here regardless. If you need the cores for a specific workload, talk to us and we will be straight about what it will and will not do.

• Extended warranty: available in the listing options below.
• Anything else: speak with us via live chat. This configuration is close to the limit of what is physically and thermally achievable at this size, so if you have something specific in mind we would much rather discuss it before you order.

🎯 What is this PC best for?

• 4K and ultrawide gaming at very high settings
• High refresh rate 1440p, where the 9800X3D's cache sets the ceiling
• 3D rendering, local AI work and heavy video timelines, where 32GB of VRAM does work no other consumer card can
• Desks and rooms where a full tower genuinely is not an option
• Anyone who needs to move a flagship machine about, given how rigid this chassis is
• Buyers who have read the trade-offs above and want this specific machine rather than the fastest one available

📊 Performance estimates

Figures are given at both 1440p and 4K, and they already account for the power limits and undervolt described above rather than quoting an unrestricted tower. Performance varies with game updates, maps, settings and background apps. These are estimates, not guarantees.

Fortnite - Competitive Settings (click or tap to expand)

1440p: 350-440 FPS
4K: 245-310 FPS
Native testing (no upscaling or frame generation).

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

1440p: 165-210 FPS
4K: 120-152 FPS
Upscaling set to Auto (DLSS / FSR / XeSS based on GPU).

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

1440p: 175-220 FPS
4K: 122-155 FPS
Native testing (no upscaling or frame generation).

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

Estimated score: 11,000-12,000

💬 Need help?

Not sure if this ITX flagship is the right fit for you? Ping us on live chat and we'll compare it honestly against our larger cases, explain the trade-offs, and guide you to the right spec for your space. You'll be talking to one of us, not a chatbot.