We are Dave's Computers, and every computer, from a basic office desktop to a four figure gaming rig, is the same eight parts doing the same eight jobs. Once you know what each part does, spec sheets stop being alphabet soup, sales pitches lose their power, and upgrade decisions get obvious. Here is every major PC part explained in plain English, from the Somerville bench where we build and repair them daily.
Every desktop is some combination of these eight. For each one: what it does, the numbers that matter, and when it is worth upgrading.
Executes every instruction the computer runs
Everything plugs into it, and it sets the ceiling
The workspace where active programs live
Draws every frame, accelerates creative and AI work
Holds everything when the power is off
Converts wall power into clean, stable voltages
Cooling is performance, not comfort
Not decoration: a spec no store lists
| Part | Key Spec on a Listing | What It Controls |
|---|---|---|
| CPU | Cores / clock speed | Multitasking, exports, game smoothness |
| Motherboard | Socket and chipset | Every future upgrade the machine can accept |
| RAM | Capacity, and two sticks vs one | Stutter, lag, how many things run at once |
| GPU | Card model and VRAM | Frame rates, creative and AI acceleration |
| Storage | NVMe vs SATA vs HDD, exact model | Boot, loading, and saving speed |
| PSU | Named brand, wattage, certification | Stability, and the safety of everything else |
| Cooling | Cooler size and type | Whether you get the performance you paid for |
| Case | Front panel airflow, fan mounts | Temperatures, noise, component lifespan |
A computer runs at the speed of its slowest relevant part. That one sentence explains most slow machines we see.
A powerful graphics card behind a weak processor sits idle waiting for work. Fast memory cannot fix a spinning hard drive. A flagship everything behind a bargain power supply crashes under load. Every machine has exactly one part holding the rest back at any given moment, and finding yours takes two steps.
From there you have three good paths: upgrade one part with confidence, shop smart with our honest prebuilt gaming PC guide, or have us assemble the whole thing balanced from the start with a custom PC build. And if you are tempted to try the assembly yourself, our build your own PC rundown tells you honestly what you are signing up for.
When customers ask where to start, this is the sequence our bench recommends for most desktops.
If anything still spins, start here. Nothing else changes how the machine feels this much, and your files migrate with it.
Two matched sticks, correct slots. Capacity ends the shuffling to disk, dual channel ends the bandwidth starvation.
The biggest single frame rate jump available, and the one upgrade that punishes a weak foundation. Confirm the supply can feed the new card before it is ordered, not after.
Processor, board, and cooling upgrades depend entirely on what your platform supports and what the bottleneck check finds. That is a conversation, not a chart, and the PC upgrade service page covers how we run it.
Patterns from years of central NJ machines, one component lesson at a time.
When a quality supply fails, the machine turns off. When a bargain supply fails, it can take the board and drives with it. The cost difference between those two outcomes is why the least glamorous part gets the least negotiable spec in every build we do.
Half the storage complaints we see come from machines whose listing honestly said SSD. The difference between a quality NVMe and a bargain drive shows up in the second minute of real work, not the first ten seconds of a benchmark, and the swap is a routine, transformative fix.
Single-stick machines cross our bench weekly. The owners bought capacity and never knew configuration existed. Moving to a matched pair in the right slots is one of the smallest invoices we write and one of the most noticeable results.
Machines rarely get slower because parts wear out. They get slower because dust builds, paste dries, and thermal throttling quietly takes a percentage every month. A cleaning and repaste is the closest thing to free speed the bench can offer.
The same bench that explains the parts also builds with them and repairs them, at the same address since 2011.
No jargon walls at the counter. You leave understanding what your machine has and why it behaves the way it does.
The $75 diagnostic names the one part worth your money, and it is credited toward the work.
We spec parts for custom builds and replace them in repairs daily. The advice comes from both sides of the bench.
Every quote lists exact components. If a cheaper part is genuinely fine, we say so. If it is a trap, we say that louder.
Most upgrades and repairs finish in days at 75 N Bridge St, with a realistic timeline given at drop-off.
Fifteen years of central NJ customers who got the straight version. That is the whole marketing plan.
The component questions we answer most at the Somerville counter.
Eight parts: the processor, motherboard, memory, graphics card, storage, power supply, cooling, and the case. Every desktop computer is some combination of these eight.
The graphics card, followed by the processor, then memory capacity and configuration. Storage speed affects load times but not frame rates.
RAM is the short-term workspace for programs that are currently running, and it empties when the power turns off. Storage is the long-term filing cabinet that keeps your files and programs permanently.
For most machines: move to a solid state drive first if you are still on a hard drive, then bring memory to 16GB or more in dual channel, then upgrade the graphics card, confirming the power supply can feed it first.
Start with the graphics card and processor for your target games or software, then choose a motherboard, memory, and power supply that support them properly. The case comes last, chosen for airflow.
On our bench: power supplies, spinning hard drives, and cooling fans, in that order. All three are wear items, and all three are affordable to replace before they take other parts with them.
One location, drop-off for residential customers. Dave's Computers is at 75 N Bridge St, Somerville NJ 08876. All builds, upgrades, and repairs are performed at our Somerville shop, and we do not offer in-home residential service. On-site arrangements are available for business clients. Curbside drop-off is available.
Bring us the listing, the spec sheet, or the machine itself. We will translate every line, flag every trap, and build or upgrade it right the first time.
📞 (908) 428-9558