Derek Tan — SFF Enthusiast, Austin TX
Derek Tan, 34
Software Engineer · Small Form Factor Community Member
Derek had been building PCs for over a decade, but always in mid-tower ATX cases. After moving to a smaller apartment in Austin, his full-tower rig dominated his desk and living space. He'd seen the SFF community pushing limits but assumed ITX meant sacrificing performance — a belief shared by most builders who haven't tested it themselves.
His goal was audacious: build a system that matched his previous full-tower RTX 4070 Ti Super + i7-14700K build in every benchmark, but inside a case under 12 liters. No thermal throttling. No noise penalty. No compromises.
Size vs. Performance: The SFF Myth
The small form factor community has long battled a perception problem. Most builders assume that cramming high-end components into a tiny case means accepting 10–15°C higher thermals, louder fans, and throttled performance. Forums are filled with horror stories: hot ITX builds, cable nightmares, and components that physically don't fit.
Derek's previous full-tower build scored 18,450 in 3DMark Time Spy with GPU temps maxing at 72°C. His research suggested an equivalent ITX build would hit 85°C+ on the GPU and thermal-throttle the CPU within 20 minutes of sustained gaming. The engineering challenge wasn't just fitting parts — it was proving the conventional wisdom wrong.
"Everyone told me to just get a bigger case. 'ITX is for HTPCs, not real builds.' I wanted to prove them wrong with data, not opinions."
— Derek Tan, SFF BuilderThe 5-Phase Build Strategy
Derek didn't just throw parts into a small case. He engineered the build in five deliberate phases over four weeks, treating each component selection as a constraint optimization problem.
Case Selection & Layout Analysis
Chose the FormD T1 (10.8L) after evaluating 8 ITX cases. Mapped every millimeter of clearance — GPU length (312mm max), CPU cooler height (53mm max), and PSU placement. The sandwich layout with a PCIe 4.0 riser was critical.
CPU & Cooler Pairing
Selected the i7-14700K but applied a -0.085V undervolt and 125W power limit in BIOS. Paired with an AXP90-X47 Full Copper cooler with a Noctua NF-A9x14 fan swap. Result: 18°C drop vs. stock settings, only 3% multi-core performance loss.
GPU Undervolting & Orientation
Used an ASUS Dual RTX 4070 Ti Super (267mm, 2.5-slot). Applied a 0.925V undervolt at 2750MHz — matching stock boost clocks but drawing 55W less. Oriented the GPU with exhaust facing the top panel for natural convection assist.
Airflow Engineering
Configured two top-mounted Noctua NF-A12x25 fans as exhaust. No intake fans — the negative pressure setup pulls cool air through mesh side panels. Added custom 3D-printed ducts to channel GPU exhaust away from the CPU zone.
Cable Management & Storage
Used custom-length silicone cables from PSlate (240mm GPU, 300mm CPU) to eliminate cable bulk. Mounted a single 2TB Samsung 990 Pro NVMe — no SATA cables, no drive cages. Every cubic centimeter optimized for airflow.
The Numbers Don't Lie
Full tower vs. 12-liter ITX — same core components, same benchmarks, same room temperature (22°C).
Full Performance. 75% Less Volume.
The numbers shocked even Derek. The ITX build didn't just "hold up" — it outperformed the full tower in CPU thermals by 6°C thanks to the undervolt and superior negative-pressure airflow. GPU performance was within 0.3% of the full tower — a margin that falls within benchmark run-to-run variance.
In real-world gaming, the difference was invisible. Cyberpunk 2077 ran at 1440p Ultra with RT Overdrive at 87 FPS (vs. 89 FPS in the tower). Alan Wake 2 hit 72 FPS (vs. 73 FPS). The 1% low frametimes were actually better in the ITX build due to the GPU undervolt producing more consistent clock speeds under sustained load.
The total build cost was $1,847 — only $63 more than the equivalent full tower build, with the premium coming from the FormD T1 case ($210) and custom cables ($45). The SFF tax, as it turns out, is largely a myth when you plan the build properly.
"I spent four weeks engineering this build and the result is a system that sits on my desk like a piece of furniture, runs whisper-quiet, and doesn't give up a single frame to a tower three times its size. The 'ITX tax' is a planning problem, not an engineering one."
5 Takeaways for Your Own ITX Build
Measure Everything Twice
ITX builds live and die by the millimeter. GPU length, cooler height, and PSU clearance must be verified against your specific case — not just the spec sheet. Derek found 2mm of extra clearance by repositioning the PSU bracket.
Undervolt Before You Upgrade Cooling
A -0.085V CPU undervolt and GPU voltage curve optimization saved more thermals than any cooler swap. Free performance headroom that most builders ignore entirely.
Negative Pressure Wins in SFF
With limited fan mounts, exhaust-only configurations with mesh panels consistently outperform intake-heavy setups in sandwich-layout ITX cases. Let physics do the work.
Custom Cables Aren't Luxury
In a full tower, stock cables are ugly. In an ITX build, they're an airflow obstruction. Custom-length silicone cables freed up 40% of the cable volume in Derek's build.
Planning Beats Budget
The $63 SFF premium came entirely from the case and cables. Every other component was identical. A well-planned ITX build costs nearly the same as a tower — the real investment is time.