The 7 most common mistakes when building a PC

We all make mistakes. But some mistakes happen more often than others. It is not hard to build a PC, but there are some common pitfalls to avoid. Those start when picking the components, but there are quite some more to think of before the last piece can be placed.

1. Buying old hardware for the price of new

You are not alone in assuming that old hardware will be cheaper than new and more powerful hardware. But often, that is not really true. The Intel processor from 3 years ago listed at your favorite online store will often still have exactly the same price as when it was released. And old mainboards can even be more expensive, because they are sought after to power all those older processor still floating around (usually, mainboards break before processors). A high price does not signal that something is new or still powerful.


Take this current offer for the i3-6100 as example. It has 2 faster successors: The i3-7100, and that one is at $100. And the i3-8100 for around the same price, which even has two cores more. The 6100 is not close to be worth $100, but there it is, at $119, as if nothing ever happened

When a new series gets released the old processors (and video cards) do get cheaper in the beginning, but only for a short time. That’s why it is so important to be aware of what is current hardware.

2. To combine an overclockable processor with a locked mainboard

This is more an Intel thing. For Intel processors, those with a K at the end are unlocked. But to overclock them you need a fitting mainboard with the right chipset: A Z mainboard (currently Z370, before it was Z270). Every time you see a K processor combined with a B or H mainboard, you should remember that this build was more expensive than needed. Because many K processors are not faster than their locked and cheaper counterparts, if not being manually overclocked.

For AMD this happens less often, as all Ryzen processors are unlocked, and both B350 and X370 chipsets allow overclocking.

3. Getting a bad power supply

How to make a build cheaper? You need a fast processor, a powerful gpu, a lot of storage. Save on the case? Well, a case can be used multiple times and you see it every day, maybe not a good idea. What happens often is cutting down on the most uninteresting part: The power supply.

And that can be a fatal mistake. A bad power supply can destroy all other components. It can also start a fire, and if that happens at the wrong time it won’t be the nice campfire kind. The psu should never be too cheap or not have enough wattage (though it also does not have to be a $100 high end model).

4. Using slow ram (especially for Ryzen)

Ramspeed matters, and not everyone knows that. Especially with current memory prices it is tempting to go with that cheap DDR4-2133 stick. For Ryzen processor especially that decision can completely slow down the processor, but also Intel processors do profit from faster ram. Note though: For Intel board, those without a Z chipset do not support common faster ramspeeds. B250 boards for example stop at DDR4-2400.

5. Not installing mainboard standoffs

Standoffs are those small metal thingies that git into the holes of the mainboard tray in your case.


You are supposed to screw only those in that connect to a screw hole in your mainboard, and their purpose is avoiding contact between the mainboard and the case. Not using the standoffs will lead to the board to short out, which in the best case just prevents the PC from booting. In the worst case it breaks it.

6. To connect the monitor with the mainboard

Hallmark of this mistake is this issue: “I built a new PC with a GTX 1080 Ti, but now CS:GO will only play at 40 FPS.” When connecting the display cable with the mainboard the integrated graphics of the processor will be used for gaming, and most of them do not manage that well.

7. Forgetting the IO shield

This one is the most annoying. You got your whole PC built, cables are managed, coolers installed, and end up with this metal bracket that does not seem to fit anywhere.


It is an IO shield, and it fits between the mainboard and the case, where the case has the cutout for the mainboard connectors. It is useful to keep dust out, but it is one of the first things to install, and often the last thing to be noticed.


Short note: Coffee Lake is live, but not available

Right now the pc-kombo system is gathering prices of Intel’s new Coffee Lake cpus. All models are integrated, and also Z370 boards are in the system. And given the performance of these processors they will be the default choice at many price points, as soon as prices are in the database.

However, there is one problem: While vendors may list them with proper prices, the Coffee Lake cpus are basically nowhere in stock. I recommend to disable them in the advanced settings (under the search button) if you want to buy a system right now, and to get a Ryzen system instead; until Coffee Lake is properly in stock.

If they were in stock, they’d be good choices for many users. The i3-8100 is a fast Ryzen 3 alternative, with 4 cores and threads as well. The i3-8350K replaces the old i5-7600K, and costs less. The i5-8400 (a hexa-core!) reaches with its turbo 4GHz, the barrier the Ryzen 5 1600 can overclock to at most, while having a slightly better IPC. The unlocked i5-8600K looks compared to that almost unnecessary, while the i7-8700K replaces the i7-7700K as the fastest consumer/gaming cpu.

Introducing Hardware Component Pages and the Case Size Visualizer

This update brings specific pages for all hardware known to the recommender. Those component pages hold a bunch of information: The detailed specifications, links to reviews and the manufacturers product page, images and current prices. User can help build this into a complete database, by providing the links and by writing user reviews, and also help by upvoting and downvoting products and provided links.

This for example is the page for the NZXT S340 case:


One special feature visible in that screenshot is the case size visualizer. Using WebGL, it renders the current case right next to the average mid case and the average small form factor case, as well as a banana. This gives a way better impression of the actual size of a case than just reading the values.

RX Vega 64 added

Almost immediately after Threadripper AMD allowed reviews for their new gpu line, Radeon RX Vega. Again there are two models: The Vega 64 and the Vega 56.


Those early reviews paint the picture of a very hard to judge gpu line. Let’s start with the Vega 56, as it is the more interesting of the two. Its recommended price is $399 in the US and 405€ in Europe. That pits it against the Geforce GTX 1070. That is a card the smaller Vega can beat, judging by the ComputerBase benchmark and the GamersNexus review. However, it uses more energy, and the reference cooler is loud. It is also uncertain that the price will stay low enough to make the card an attractive option, as it might be a good enough mining card.

The Vega 64 looks so far to be a worse option, but it is the one that is available in Europe right now. It costs more: 649€ in Germany. That makes it more expensive than a GTX 1080, while being slower than that card and using more energy. In the US it is at $599, but at $699 for the version with a liquid cooler, both are out of stock.

Since the Vega 64 is available and benchmarks were released it is listed in the gpu meta benchmark:


Interesting and almost typical for AMD gpu releases is the talk about future performance improvement. For Vega, it looks like some hardware features are not being used yet. And the driver support seems to be bad. It is quite likely that performance will improve later on. If prices stay low enough the RX Vega 56 could then become a good alternative to the GTX 1070. And the Vega 64 might become a valid alternative to the GTX 1080, if it also gets a small price cut. But of course, one should not buy a gpu based on speculation such as this.

By the way, with regards to price cuts: AMD offers those Vega cards with some bundles. But those are not attractive at all. They contain a price reduction when buying a Ryzen 7 processor, some specific, expensive mainboards, and an additional discount on some Freesync-enabled displays. Gamers do not need Ryzen 7 processors, and almost no one needs those expensive mainboards, while the chosen Freesync displays are too expensive as well. I recommend against those bundles.

If those gpus happen to become more attractive options later on we will surely see that here, as those card would be picked up as options in the hardware recommender. But for now, Vega is not there yet.


AMDs latest processor is a monster. The Threadripper 1950X has 16 cores and 32 threads and a turbo clock of 4 GHz. Its smaller brother, the 1920X, still has 12 cores and 24 threads and the same turbo clock.

Those are not processors for mere gaming, and they are also not particularly suited for games. That is not to say that they fail running them, the new processors just are not better at that than the bigger Ryzen processors or Intel’s alternatives. Accordingly that’s their position in the gaming meta benchmark:


But Threadripper is a lot stronger in applications that can use those many cores. In the benchmarks we see the big model before the more expensive Intel Core i9-7900X:


There are still more results to be added, I fully expect the 1920X to beat the i7-7820X in the benchmark with some additional data. But that will have to wait, as Vega got released and is about to be added to the recommender.