Buying a power supply is usually the most boring part of a PC build. You spend weeks obsessing over GPU clock speeds or whether that specific AIO cooler will fit, but when it comes to the pc power supply case—or the PSU shroud and mounting area—most people just shrug. They figure if it fits, it sits.
That's a mistake. A big one.
Honestly, the way your case handles the power supply dictates your entire build's thermal health and how much you're going to swear while trying to close the back side panel. If you buy a compact case with a cramped PSU basement, you're basically asking for a cable management nightmare that chokes your airflow.
The Shroud Debate: Aesthetic vs. Airflow
For years, we didn't have shrouds. You’d just see this messy "mustard and ketchup" bundle of cables spilling out of a silver box at the top or bottom of the chassis. Then NZXT and Corsair started popularizing the PSU shroud—that metal shelf that hides the power supply and all the extra cable slack.
✨ Don't miss: What Did Black People Invent? The History You Weren't Taught in School
It looks cleaner. Way cleaner.
But there’s a catch. Some pc power supply case designs make the shroud so tight that the PSU fan is basically gasping for air. If you're mounting your PSU with the fan facing down, and your case is sitting on a thick shag carpet, you’re essentially suffocating the component that keeps your whole system from exploding. Modern units like the Corsair RMx series or the EVGA SuperNOVA line are efficient, but they still generate heat.
I’ve seen builds where people flip the PSU so the fan faces up into the case. In a shroudless "old school" case, that’s fine. In a modern pc power supply case with a solid metal shroud, you’re just creating a pocket of hot, dead air. Unless that shroud is perforated—like what you see on the Lian Li Lancool III—don't do it. You want that independent thermal cycle where the PSU pulls cool air from the bottom and exhausts it out the back.
ATX 3.0 and the 12VHPWR Cable Crisis
Let’s talk about the elephant in the room: the NVIDIA 40-series and 50-series cards. These things use the 12VHPWR connector (or the updated 12V-2x6 version). These cables are stiff. If your pc power supply case doesn't have enough clearance between the side panel and the GPU, or if the PSU basement is too shallow to allow for a gentle cable bend, you risk a bad connection.
We’ve all seen the photos of melted connectors. Most of the time, it’s because the cable was bent too sharply right at the plug because the case was too narrow. Experts like JonnyGuru (Jon Gerow) have pointed out repeatedly that cable strain is a silent killer for high-wattage components. When picking a case, you need to look at the "width" specification, not just the height.
Size Issues: SFX vs. ATX in Small Form Factor
If you’re building a Mini-ITX rig, the pc power supply case constraints get weird. You’ve got SFX, SFX-L, and some "small" ATX units.
- SFX: The tiny standard. Great for compatibility.
- SFX-L: Slightly longer. Often has a bigger, quieter fan.
- ATX: Don't even try it in a SFF (Small Form Factor) case unless the manual specifically says it fits.
I recently helped a friend try to shove a 160mm long ATX PSU into a "compact" mid-tower. It "fit" on paper. But once the modular cables were plugged in? The connectors hit the hard drive cage. We had to take a dremel to the drive cage just to make the power cables turn 90 degrees. It was a mess. Always check the "Max PSU Length" spec on the manufacturer's website. If your PSU is 150mm, look for a case that supports 170mm+. Give yourself that 20mm of breathing room for the cable heads.
✨ Don't miss: How to Actually Download Files from iPhone Without Losing Your Mind
The Hidden Value of Modular PSU Clearances
Modular power supplies are a godsend, but they actually require more room in the pc power supply case than non-modular ones. Why? Because the plastic connectors that plug into the PSU face add about 15-20mm of rigid length before the wires even start to bend.
In a tight case like the Fractal Meshify 2 Compact, every millimeter matters. If you're using a high-wattage unit (1000W+) these are almost always longer than the standard 140mm depth. A 1000W Seasonic Focus is roughly 140mm, which is tiny, but a 1000W EVGA G-series can be 180mm. That 40mm difference is the difference between a clean build and one where you have to remove the 3.5-inch drive bays just to fit the cables.
Noise, Vibration, and Rubber Gaskets
One thing people never talk about is vibration. A PSU has a fan. Fans spin. Spinning things vibrate.
Cheap pc power supply case options are just thin stamped steel. If the PSU is screwed directly to that steel with no padding, you get a low-frequency hum that will drive you insane. Better cases—think Be Quiet! or higher-end Phanteks—use rubber standoffs or foam gaskets where the PSU sits.
If your case doesn't have these, you can actually buy little silicone gaskets to put between the PSU and the case frame. It sounds like a small detail, but it’s the hallmark of a "pro" build versus a "budget" one.
Orientation: Fan Up or Fan Down?
This is the age-old question in the pc power supply case community.
- Fan Down: This is the standard. It pulls fresh air from under the case. It keeps the PSU in its own thermal zone.
- Fan Up: Use this if you’re putting your PC on a thick carpet (which you shouldn't do anyway) or if your case has no bottom ventilation.
The downside of Fan Down is dust. Your PSU becomes a vacuum cleaner for your floor. If your pc power supply case doesn't have a high-quality, slide-out dust filter on the bottom, you're going to have to open that PSU up and blow it out every six months. And trust me, you don't want to open a PSU; the capacitors in there can hold a lethal charge even when unplugged.
Real World Example: The "Lian Li O11" Effect
The Lian Li O11 Dynamic changed how we think about the pc power supply case layout. It put the PSU behind the motherboard tray in a dual-chamber design. This is brilliant because it removes the PSU length restriction almost entirely. You can put a massive, 200mm long "mining" PSU in there and it won't affect your GPU clearance or your front intake fans.
If you’re planning a high-end workstation with a beefy power supply, the dual-chamber layout is the gold standard. It separates the two biggest heat generators—the GPU and the PSU—into different physical spaces.
Actionable Steps for Your Next Build
Don't just buy the prettiest case you see on Instagram. Follow these steps to ensure your pc power supply case doesn't ruin your build:
- Check the Depth: Look at your PSU length (e.g., 160mm) and add 30mm for cables. Ensure the case "Max PSU Length" exceeds this total.
- Measure Side Clearance: If you have a 40-series GPU, ensure your case is wide enough that the power cable isn't pressed against the glass.
- Prioritize Perforated Shrouds: If you want to mount your PSU fan-up for aesthetics, ensure the shroud has holes. If not, mount it fan-down.
- Clear the Basement: If your case has a removable HDD cage in the basement, take it out if you aren't using spinning drives. It opens up a massive amount of "tuck space" for cable management.
- Look for Filters: Ensure the bottom intake has a nylon mesh filter, not just a punched metal plate. Nylon catches way more dust.
A power supply might be a "dumb" box of electronics, but the way it interacts with your pc power supply case determines whether your PC is a quiet, cool-running machine or a hot, vibrating mess of cables. Get the dimensions right before you click "buy."