Rune Three | RTX 5080 + Ryzen 7 7800X3D | Ready-to-Go Gaming PC | PC36

🐺 Rune Three

A flagship that fits on a bookshelf

An RTX 5080 is a 4K graphics card, and the machines built around one are usually the size of a bedside cabinet. Rune Three puts one inside 10.4 litres of anodised aluminium with a front panel milled from solid FSC-certified walnut: a closed object, no glass and no lighting, small enough to stand on a shelf and quiet enough at idle that you would forget it was on.

Nothing in it is a smaller version of anything. An RTX 5080 with 16GB of GDDR7 and a Ryzen 7 7800X3D is a 4K pairing by any measure, and at 1440p there is very little you can ask of it. This is the same hardware you would put in a full tower, standing beside your monitor instead of under the desk.

It only works because of how it is built. Only a handful of RTX 5080 models are slim enough to clear the Terra's spine, and we source and verify one that does. The card sits on a rigid riser in its own side of the chassis, the base intake is fitted with a grille over it, the 12V-2x6 cable is routed with a proper bend radius rather than forced into the nearest gap, and the fan curves are set by hand on the finished machine. This is the most demanding thing we put in this case and the build that takes us longest.

🧬 Built to last, designed to evolve

Built on AMD's AM5 platform, which AMD have committed to supporting into 2027 and beyond. The processor, memory and storage can all be upgraded without replacing the motherboard, and the board's second M.2 slot is free for a later drive. This is the top of what will sensibly go in this chassis, so the honest upgrade path from here is a larger case rather than a larger card, and we will say so on live chat rather than sell you something that cannot breathe.

📃 Specifications

• 🧠 CPU: AMD Ryzen 7 7800X3D (package power capped at approximately 90W)
  Click or tap for deeper spec info

  • 8 cores, 16 threads of Zen 4, boosting to 5.0GHz, with 96MB of L3 cache thanks to AMD's 3D V-Cache
  • The cache is the whole point. Stacking 64MB of extra L3 on top of the die means far more of a game's working data sits next to the cores instead of out in system memory. In the games that care - large open worlds, simulation titles, heavily modded games, competitive shooters at very high refresh - that is worth more than raw clock speed
  • Why we cap it at around 90W, stated plainly. The cooler that fits here is 67mm tall. Rather than let the chip chase a power limit it cannot cool, we set a sensible ceiling. In games the 7800X3D typically draws well under 90W anyway, so the cap costs essentially nothing where it matters. In long all-core work such as video exports or rendering, this machine will finish behind the same processor in a full tower
  • Being straight about pairing: at 1440p with settings up, and at 4K in everything, the graphics card is what sets your frame rate here. The X3D cache earns its keep in the competitive and simulation titles where the processor leads
  • The 7800X3D is not multiplier-overclockable. The stacked cache sits above the cores on this generation, so AMD lock the multiplier to protect it. Tuning here means undervolting via Curve Optimiser, which in a case this size is the more useful direction anyway
  • Socket AM5, so a faster processor can go in later without replacing anything else
• ❄️ CPU cooler: Thermalright AXP120-X67
  Click or tap for deeper spec info

  • A low-profile top-down cooler, 67mm tall, with six heatpipes and a full-size 120mm fan
  • Most coolers at this height use a 92mm fan and have to spin it hard. The 120mm fan here moves the same air far more slowly, and fan speed is what you actually hear
  • Top-down design, so it also pushes air across the motherboard's power stages and memory. In a chassis this dense that is worth having
  • Set against a 90W processor ceiling, this is a good deal more cooler than the number asks for, which is the point: it holds that ceiling through normal gaming without having to spin up to do it. Under a long all-core load you will hear it, and on this build the graphics card is the louder half anyway
  • An all-in-one liquid cooler is not a practical option in this chassis alongside a card of this size, and we would rather explain that than leave you wondering. Air cooling here is the correct answer rather than a shortcut
  • Mounted with Thermalright's own paste, applied by hand rather than using a pre-applied pad
• 🔲 Motherboard: ASUS TUF Gaming B850I WiFi Neo (Mini-ITX)
  Click or tap for deeper spec info

  • 8+2+1 power stages rated at 80A on a 10-layer PCB. Plain English translation: far more power delivery than this processor will ever draw, particularly with a 90W ceiling in place, and it stays cool doing it
  • ASUS's first TUF Gaming Mini-ITX board. Chosen here for build quality and for how well the board itself sheds heat, which in a chassis this dense matters more than a feature list
  • Two M.2 slots, one Gen5 and one Gen4, both under heatsinks. Only one is used on this build. The Gen5 slot is wired straight to the processor, so a Gen5 drive later runs at full speed
  • Two DDR5 slots supporting up to 128GB, both used here with a matched pair
  • Wi-Fi 6E and Bluetooth built in, aerial supplied. Realtek 2.5 Gigabit Ethernet
  • Twelve USB ports in total including a 20Gbps rear Type-C. On a case with two front ports, a generous rear panel matters more than usual
  • PC36 only uses motherboards chosen for stability and longevity. See our Trusted brands page
• 📏 Memory / RAM: 32GB (2×16GB) DDR5-6000 CL36
  Click or tap for deeper spec info

  • A matched pair running dual channel at DDR5-6000 CL36, enabled via EXPO in the BIOS before it ships
  • DDR5-6000 is the speed Ryzen on AM5 runs best at. It keeps the memory controller and the memory running in step with each other, which is where the platform is happiest, and going faster on paper often makes it slower in practice
  • 32GB is the right amount for a machine at this level. It covers modern games at maximum settings with plenty spare for a browser, Discord and a stream running alongside
  • Both memory slots are used, so a later capacity increase means replacing the pair rather than adding to it. That is a Mini-ITX reality rather than a choice we made
  • 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

  • Rated at 5,000MB/s or better. Games load in seconds and Windows feels instant
  • TLC rather than QLC on this tier. TLC holds its speed during long sustained writes where a cheaper QLC drive slows down, and it has better write endurance. It costs more and we fit it here because a machine at this level is likely to be moving large files around
  • We fit 1TB as standard across the whole range rather than varying it by price, so comparing our machines to each other is straightforward. The 2TB option is below, and at this price point it is the upgrade we would encourage most
  • The board's second M.2 slot is free, so adding a second drive later is a real option, and it can be a Gen5 drive if you want one
  • Specification guaranteed, model may vary. Happy to confirm the exact part on request
• 🎮 Graphics card: NVIDIA GeForce RTX 5080 16GB
  Click or tap for deeper spec info

  • Blackwell, 16GB of GDDR7 on a 256-bit bus. A 4K card in the proper sense, and comfortably more than any 1440p monitor will ask of it
  • DLSS 4 with Multi Frame Generation. Transformer-model upscaling is a real visual step up from the older model, and on a card this fast it is what turns 4K from playable into effortless
  • Heavy ray tracing at 1440p and at 4K is genuinely comfortable here. This is the tier where ray tracing stops being a setting you weigh up
  • Dual NVENC encoders. If you stream or record seriously, NVENC is what most streaming software is built around. AV1 supported for both encode and decode
  • The card has to be a slim model, and that is worth understanding. The Terra's spine sets a hard ceiling on graphics card width once a 67mm cooler is fitted. Only a small number of manufacturers make an RTX 5080 that clears it, so we source one of those specifically rather than taking whatever is cheapest that week. Those cards cost more than a standard 5080, and that difference is in the price of this machine rather than hidden in a footnote
  • Powered by a 12V-2x6 connector. In a case this size the bend radius on that cable is a real consideration, so it is routed with proper clearance rather than folded to make it reach
  • The chipset and VRAM are guaranteed: it will always be an RTX 5080 with 16GB. The AIB brand varies with availability within the models that fit, and we only use established manufacturers. See our Trusted brands page for more info
• 🧰 Case: Fractal Terra, Graphite
  Click or tap for deeper spec info

  • 10.4 litres internally, 11.4 including the feet. 343 × 153 × 218mm. Mini-ITX only
  • Anodised aluminium with a front panel of solid FSC-certified walnut. Not a veneer and not a printed finish - it is a machined block of real wood, so the grain is different on every one. It is the reason people buy this case
  • Three finishes, all with the same walnut front. Graphite is a deep graphite black and is what we build as standard. Silver is a pale silvery white, and Jade is a soft jade green. All three are anodised aluminium rather than paint. We will build any of them at no extra cost, so tell us on live chat which you want
  • The sliding spine is the whole design, and on this build it is the whole story. The spine moves steplessly through 30mm, trading cooler height against graphics card width. Slid one way you get 77mm of cooler and a slim card; slid the other you get 48mm of cooler and a card up to 77mm wide. Rune Three sits near the cooler end, and that is precisely why the graphics card has to be a slim model
  • Graphics cards up to 322mm long. SFX and SFX-L power supplies up to 130mm
  • Two 2.5 inch drive mounts. One 120mm fan mount in the base
  • Front I/O is USB-C, one USB-A and a power button
  • No glass panel and no lighting. The Terra is a closed object, and the internals are black as standard because you are not meant to be looking at them
  • A rigid PCIe riser connects the graphics card, which is what allows a case this shape. The one Fractal supply with the Terra runs at PCIe 4.0, which costs low single-digit percent on a card of this class and nothing at all on the board's Gen5 M.2 slot, because that is wired straight to the processor
  • Small form factor builds take considerably longer to assemble, cable and tune than a standard tower. That work is included in the price rather than added to it, and on this build it is the most of it
• 🌬️ Case cooling: 1 × 120mm base intake with grille, fitted by us
  Click or tap for deeper spec info

  • The Terra ships with no fans at all. We fit a 120mm in the base mount, feeding cool air straight up into the chassis from underneath. On this build it is doing the hardest work of any fan in the range
  • We fit a grille over it as standard. In a case this tight a stray cable can find a fan blade, and a three pound grille is cheaper than the phone call. It is the sort of thing that only shows up when you have built a lot of these
  • Plain black, four-pin PWM, no lighting. The Terra is not an RGB case and we do not treat it like one
  • Fan curves are set by hand before dispatch and verified through our standard stress testing rather than assumed. On this build that tuning is the difference between a machine you enjoy having in the room and one you resent
  • Honest expectation setting: this is the most demanding configuration we put in this case. At idle and in light use it is very quiet. Under a heavy gaming load you will hear it, and clearly more than you would hear the same components in a full tower. Taking the Premier Optimisation and giving it air on all sides both help. If silence under load is your priority above everything, a larger case is the honest answer and we will tell you that on live chat
• ⚡ Power supply: Thermaltake Toughpower SFX 850W 80+ Gold, fully modular
  Click or tap for deeper spec info

  • 850W rather than the 750W used on the tiers below, because this build asks for it. The card and processor together draw around 450W in a heavy game, and Blackwell cards are known for short transient spikes well above their rated draw. The extra headroom keeps the supply comfortable rather than working at its limit in a case with no room to spare
  • SFX form factor, because that is what a case this size takes. An SFX unit is roughly half the volume of a standard ATX supply and costs considerably more for the same wattage, which is one of the hidden expenses of building small and one we would rather explain than bury
  • Fully modular, which in 10.4 litres is a functional requirement rather than a tidiness preference. There is nowhere to put a cable you are not using
  • 80 PLUS Gold, and ATX 3.1 certified with a native 12V-2x6 cable for the graphics card. No adapters, which matters both for safety and for routing in a case this tight
• 🔌 Cabling: Black cabling, routed for a small chassis
  Click or tap for deeper spec info

  • Short runs, routed to keep the vented panelling clear on both sides and to stay out of the spine's travel
  • The 12V-2x6 cable is routed with a proper bend radius rather than forced into the nearest gap. That connector does not tolerate being crushed against a panel, and getting it right next to a card this size is a large part of why this build takes the time it does
  • Fully modular, so nothing unused is installed
• 📶 WiFi / Bluetooth / Ethernet: Wi-Fi 6E, Bluetooth and 2.5G Ethernet, included
  Click or tap for deeper spec info

  • Built into the ASUS TUF Gaming B850I WiFi Neo. No separate adapter needed, and the aerial is supplied in the box
  • Wi-Fi 6E adds the 6GHz band, which is far less congested than 2.4 and 5GHz in a busy household. It is plenty of wireless for anything you will do on this machine
  • 2.5 Gigabit wired Ethernet, which we would still recommend over wireless for competitive play
• 🪟 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, the 90W package power ceiling set, 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

  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 profile
  • This is the build in the whole Rune range where it does the most good. The most heat in the least space means the fan curve and the processor voltage decide how the machine feels to live with. If you are spending this much on a small computer specifically so it can sit out in a room, take this option

  PC36 Ultimate Performance Tune, available in the listing options

  • Advanced tuning: memory tune, Curve Optimiser undervolt and GPU overclock on top of everything in Premier
  • The 7800X3D has a locked multiplier, so tuning it means undervolting rather than overclocking. In this chassis that is the more valuable direction anyway - less voltage means less heat, which means lower fan speeds for the same performance
  • The graphics card is where the frames are on this build, and a properly tuned 5080 has real headroom. Combined with the memory tune, this is the option to take if you want everything the hardware has
• 🛡️ Warranty: 3 years parts & labour (return to base)
  Click or tap for deeper spec info

  • Standard 3-year coverage included, parts and labour both. The same warranty as every machine we sell, regardless of price
  • Optional extended warranties in the listing options below

👁️ Transparency notes

• The processor runs to a 90W cap, which costs nothing in games and does cost time in long rendering work (click or tap to read more)

  In games it makes no meaningful difference, because the 7800X3D is unusually efficient and rarely reaches that ceiling while playing. In sustained all-core work - long video exports, heavy rendering, large compiles - this machine will finish behind the same processor in a full tower. If that kind of work is a large part of what you do, tell us on live chat and we will point you at a tower instead.

• Only a handful of RTX 5080 models physically clear this case, and sourcing one carries a premium that is in this price (click or tap to read more)

  The Terra's spine sets a hard limit on card width alongside a 67mm cooler, and only a handful of RTX 5080 models clear it. We source and verify one that does. Those cards carry a premium over a standard 5080 and that premium is in this price. If you have a specific 5080 in mind, ask on live chat before ordering and we will tell you honestly whether it goes in.

• This is the loudest build we make in this chassis: very quiet at idle, audible under a heavy load (click or tap to read more)

  A 360W class graphics card and a capped 8-core processor in 10.4 litres cannot be as quiet as the same parts in a full tower - there is simply less air and less surface area. At idle and in light use it is very quiet. Under a heavy load you will hear it clearly. We tune the fan curves by hand to make that as pleasant as we can.

• 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 of this size and weight will sag and sway at its outer end, and in a chassis this dense that movement is a real risk to the card and to the slot it sits in. The restraint stops it, and it is part of how we make a build like this safe to own and safe to move.

• 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.
• Listen guys - we'd love to provide a can of Neck Oil with every purchase, but we're not licensed alcohol sellers, so please stop asking 😅 (It's just there for scale, and we like the label design!

🛠️ 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.
• PC36 Premier Optimisation: available in the listing options below.
  Click or tap for more info

  The upgrade we would take first on this build, ahead of any hardware change. The most heat in the smallest space is exactly where hand-tuned fan curves and a proper undervolt pay off. Worth it if the machine is going somewhere you sit near it, which for most Terra buyers is the whole point. Less relevant if it lives out of earshot and you always wear a headset.

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

  Worth taking on a machine at this level, since a card this capable tends to mean playing the large modern titles that run past 100GB each. The board's second M.2 slot is free, so you can also defer this and add a drive later, including a Gen5 one.

• 32GB to 64GB memory: available via live chat.
  Click or tap for more info

  Worth it if you edit video, run virtual machines, or work with large datasets alongside gaming. Not worth it for gaming alone - no current game benefits, and the money does more good elsewhere. Because both slots are occupied this means replacing the pair, so it is cheaper decided now than later.

• Silver or Jade colourway: available via live chat, at no extra cost.
  Click or tap for more info

  The Terra is made in Graphite (a deep graphite black), Silver (a pale silvery white) and Jade (a soft jade green), all three with the same solid walnut front. We build any of them for the same price, so this is purely a question of which one you want in your room. Tell us before you order.

• CPU upgrade to Ryzen 7 9800X3D: choose it from the quick-add upgrades, or speak with us via live chat.
  Click or tap for more info

  Worth it if you play at very high refresh rates in processor-limited games, where the newer chip is meaningfully quicker. It is also fully unlocked, unlike the 7800X3D, because the second-generation cache sits underneath the cores instead of on top. The honest caveat in this chassis is that the 9800X3D draws more power to do it, so it runs under the same kind of ceiling and gives up more of its multi-core top end than it would in a tower. The gaming advantage largely survives. Less worth it if you play mostly at 4K, where the card sets the pace regardless.

• Graphics card upgrade: not one we would take, and we will say why.
  Click or tap for more info

  This is the top of the Rune range because an RTX 5090 will not physically go in this chassis, and we will not pretend otherwise. If you want more than a 5080, the honest answer is a bigger case, and we would rather build you the right machine than the one with the biggest number on the box. Ask us on live chat and we will show you what that looks like.

• Extended warranty: available in the listing options below.
• Anything else: speak with us via live chat. This is a small case with real limits, so if you have something specific in mind we would much rather discuss it before you order than have you discover a constraint afterwards.

🎯 What is this PC best for?

• 4K gaming at high to ultra settings with DLSS, which is what this card is built around
• 1440p gaming at maximum settings, including heavy ray tracing
• Competitive shooters at very high refresh rates
• Simulation games, large open worlds and heavily modded titles, where the X3D cache does its best work
• Streaming and recording with NVENC, the encoder most streaming software is built around
• Buyers who want serious hardware in an object they are happy to leave on show

📊 Performance estimates

Figures are given at 1440p and 4K. Performance varies with game updates, maps, settings and background apps. These are estimates, not guarantees, and they account for the 90W package power ceiling.

Fortnite - Competitive Settings (click or tap to expand)

1440p: 305-390 FPS
4K: 190-250 FPS
Native testing (no upscaling or frame generation).

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

1440p: 130-168 FPS
4K: 86-115 FPS
Upscaling set to Auto (DLSS / FSR / XeSS based on GPU).

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

1440p: 148-186 FPS
4K: 90-119 FPS
Native testing (no upscaling or frame generation).

💬 Need help?

Not sure if this is the right spec for you? Ping us on live chat and we'll help you choose the perfect PC for your games, work and budget. You'll be talking to one of us, not a chatbot.