When I built my first custom PC in 2017, I made quite a few mistakes and promised myself I wouldn't repeat them in subsequent builds. Most of those errors have been fixed in the new PC I built earlier this year – except for one. If I could turn back time, the only thing I would change is the power supply unit (PSU).
Choosing a power supply with just enough wattage is the first mistake.
Choosing a power supply that is both good and not too expensive is much harder than you might think. The market is flooded with countless brands, and even within the same brand, the quality of different models varies significantly.
One of my first decisions was to choose a power supply with just enough wattage for the current setup, plus a little extra for future graphics card upgrades. The reasoning sounds logical: newer generation graphics cards are often more powerful but also more energy-efficient, so why spend extra money on a 'backup' when there are no plans to upgrade to high-end hardware anytime soon?
I read that the graphics card I intended to buy – a used RX 6800 XT – required a power supply of around 650W. After consulting the Cultists Network PSU Tier List and comparing it with models available domestically, I chose the Cooler Master MWE V2 White 700W (European 230V version), which is near the bottom of the C-tier – not high-end, but still considered safe.
I thought that this power level was sufficient, with some room for future upgrades. That was my first mistake.
I bought my power supply right before the Radeon RX 9000 series and GeForce RTX 50 series were released. Now that I know the RX 9070 XT requires a 750W power supply, I really wish I had chosen at least one with that wattage from the start.
Choosing a non-modular power supply is the second mistake.
If you're unfamiliar with the concept of modularity, the difference is quite simple: modular PSUs use detachable cables, while non-modular PSUs have all the cables bundled together in one large bundle.
There is also a semi-modular type, which combines both styles, where important cables like the 24-pin motherboard cable and CPU cable are fixed, while SATA or Molex cables are detachable. However, this type is becoming increasingly rare, as the market is mainly divided into two distinct segments: inexpensive non-modular and more premium fully modular.
Non-modular power supplies are usually a bit cheaper due to lower manufacturing costs, but the convenience of modular PSUs is undeniable. When you need to replace cables due to frequent plugging and unplugging, or want to use custom cables for a more aesthetically pleasing look, modular PSUs allow you to do so easily.
At the time, a fully modular power supply like the Cooler Master MWE Gold 750W V2 was only about $20 more expensive. I was overconfident, thinking that with my experience in cabling and building PCs, I could easily "swallow" the price difference. Since I didn't plan on installing an HDD, I thought there would be plenty of space in the drive bay to hide all the excess cables.
Problems arise during actual assembly.
The initial PC assembly process went quite smoothly. It wasn't until I started installing the power supply and plugging in the cables that I realized just how troublesome a non-modular PSU could be.
Larger cables like the 24-pin motherboard cable, CPU cable, or 8-pin PCIe cable aren't too difficult to handle. They can be routed out of the bottom of the case and neatly organized.
The problem was that I forgot about the number of thick Molex and SATA cables that come with a typical power supply. My setup didn't use any of them, and the inability to quickly detach them became a nightmare.
Not only were there many wires, but they were also stiff and bundled together, making it even harder to fold and hide them. After about 15 minutes of struggling, I managed to stuff most of the excess wires into the empty drive bays in the case. But the trouble didn't end there: the side panel still wouldn't close because the wires were sticking up. Ultimately, I had to cram everything even tighter – even though my instincts told me not to – before I could close the case and complete the assembly.
Paying extra for a more powerful modular PSU is absolutely worth it.
In total, I spent over an hour just getting the wiring to look somewhat tidy on the tempered glass panel. Looking back, I wish I had spent a little more on a modular power supply to save time and effort.
Besides the advantage of detachable cables, I can also choose a higher wattage PSU with better efficiency, such as 80 Plus Gold or Platinum, instead of the 80 Plus White standard of the power supply I'm currently using.
Besides the Cooler Master MWE Gold 750W V2, there are many other worthwhile modular PSU options on the market, such as the be quiet! Pure Power 13M 750W, Thermaltake Toughpower GT 750W, or Thermaltake GF1 750W.
In fact, 850W power supplies are usually only about $10–20 more expensive, and that's probably a smarter choice, providing ample room for upgrades to high-end graphics cards like the RTX 5080 for the next few years.
At least I'm lucky because my case has a PSU shroud wide enough to hide most of the messy cables. If the case didn't have this space, you'd likely have to leave cables dangling in unsightly and inconvenient places. Not to mention, excess cables obstruct airflow, which is especially dangerous in smaller cases – another reason why modular PSUs are a good idea.
Looking back, I really wish I had spent more money on a modular power supply from the start. Unused cables just accumulate more dust, making regular cleaning a hassle. And every time I opened the right side panel, it felt like I had to start the whole cabling process all over again.