From the FAQ: CPU vs. GPU Mining

October 5, 2020
Salad Guide

Despite the Central Processing Unit’s (CPU) knack for problem solving (a.k.a. hashing), it’s not the first component that comes to mind for the crypto convert. Nowadays, mining outfits rely on racks of super-charged ASICs and GPUs to churn out Bitcoin and Ethereum—or even the almighty Dogecoin.

At Salad, our goal is to help users get the most out of their idle computational resources, no matter their hardware. Let's find out if CPU mining with Salad is right for you.

How Is CPU Mining Different?

A worker figurine next to a metal Bitcoin.

The basics of CPU mining are similar to GPU mining, but the devil's in the details. There are a few key differences worth mentioning before you get started.

1. Protocol Optimization

Many coins are optimized to take advantage of both CPU and GPU power. Salad uses your CPU to mine for Monero (XMR) via XMRig. It’s one of the best known and most reliably profitable coins for CPU mining—though results aren't always guaranteed.

2. Variable Earning Rates

CPU earning rates are affected by many of the same factors as GPU mining, such as:

  • hashrate
  • cooling and hardware maintenance
  • mining difficulty and luck

If you’re unfamiliar with these topics, check out "A Gamer's Guide to Blockchain and Crypto." It might also be helpful to read about the most common mining pool payout schemes.

3. Lower Hash Power

Graphics cards generally perform specialized processes like rendering game graphics and particle effects, whereas the CPU is a jack-of-all-trades. It's like your computer's brain, tasked with overseeing everything from your Excel spreadsheets to those 50 browser tabs you've got open for someday.

The more background processes you have running, the less spare power your CPU will have to contribute to hashing. This makes CPU mining essentially ineffectual unless you’re truly AFK.

The CPU's wide range of responsibilities benefit from its equally wide skill set. But when it comes to the highly parallelized computations required for mining, the GPU shines. A CPU can't output the same raw hash power that a GPU produces, and you may earn more slowly as a result.

Hardware Specialization

Outside of Bitcoin mining (which is dominated by ASICs), the majority of blockchain hash power is derived from GPUs. That's because CPU miners run up against notable hardware limitations, including:

  • relying on RAM instead of VRAM for hashrates
  • elevated sensitivity to background processes and apps
  • fewer arithmetic logic units (ALUs)—they do less math.

In plain English: unlike most consumer graphics cards, your CPU doesn’t have dedicated RAM. It relies entirely on the sticks in your motherboard for support. You may have a badass CPU with 12 cores, hyperthreading, and the works—but you can't go the distance with 2GB of RAM.

Will CPU Mining Harm Your Computer?

A man using a laptop clutches his head in frustration.

While GPU mining is considered safe for long-term use, the jury's still out on CPU mining. Your primary concern with any important piece of PC hardware should be overheating. Unsafe temperatures in vital components (like your GPU and CPU) can result in immediate failure, and possibly inflict permanent damage on your rig.

For those of you breaking out in a nervous sweat, take comfort! The worst you'll typically encounter is a blue screen or shutdown. Drivers are smart, and they’ll use whatever means necessary to protect your PC from total meltdown.

But many CPUs don’t have extraneous drivers, and won't get upgraded as often as your GPU—so it's your job to protect your PCs brains from getting scrambled. Here are some pro tips to mining safely with your CPU:

Keep CPU Temperature Low

Most CPUs allow you to check running temperature directly in BIOS, but third-party software like HWMonitor can be handy for keeping an eye on it. We generally recommend keeping your CPU temperature below 80°C. There’s wiggle room on either side of that number (depending on your specific model, overclocking, and other factors) but it's a good benchmark.

Limit Other Processes

The more that you ask your CPU to do, the harder it will work. The harder it works, the hotter it will get. To avoid crashing your PC—from heat or simple overload—keep background and simultaneous processes to a minimum while mining.

Trying to watch YouTube videos, play games, or even browse the internet may put unnecessary strain on your CPU and cause performance issues. Not to mention, it will seriously reduce your earning rates.CPU mining is a strictly AFK activity.

Clean Your Computer Often

There should be as little dust and detritus as possible on the inside of your PC, down to the fans and boards alike. Get a can of compressed air and go to town on the inside of your PC—it all needs a good spring cleaning once in a while.

Pay special attention to the fans on the GPU and CPU, as these directly cool your hottest components and tend to get clogged quickly. Take care to give your PC breathing room, too.

Install Cooling Systems or Components

Extra cooling is never a bad thing, so long as you pay attention to maintaining proper airflows. There’s a range of components that you can add to help keep your PC nice and chilly, such as:

Any of these extras may help to keep your vital components in safe temperature ranges.

Mine With Caution on Laptops

Laptops have become increasingly powerful over the years, and many of them are on par with high-performance gaming rigs. Yet there’s one disadvantage a laptop can never overcome: cramped insides.

Laptop designers need to preserve economy of space, and that often means shoving important components right next to each other, with no elbow room for extra fans and cooling components. As a result, laptops tend to run hot. If you're not watching the internal temperature, using a laptop for CPU mining can be risky (unless you live in the Arctic). Miners using laptops should take extreme caution to ensure proper cooling as best you can.

CPU and GPU mining share much more in common than you might think—with some important caveats. If you’re interested in downloading Salad, but you're not sure whether your graphics card is up to snuff, CPU mining affords another no-hassle way to profit from your PC.