Onboard Audio vs Sound Card Explained

For most people, onboard audio is good enough. The sound chip built into your motherboard handles web browsing, YouTube videos, video calls, and casual gaming just fine. About 80% of desktop PC users never need anything more.

A dedicated sound card makes sense when you own quality headphones (above $100), do competitive gaming where hearing footsteps matters, create music or podcasts, or notice hissing and static during quiet moments. The difference becomes clear once you know what each option does well, and where each one falls short.

Quick Comparison Table

What Is Onboard Audio?

Onboard audio is the sound system built directly into your computer's motherboard. Every desktop motherboard and laptop has one. It includes a small chip called a codec that converts digital sound files into analog signals your speakers or headphones can play.

Most motherboards today use Realtek audio codecs. Common models include the ALC1200, ALC897, and ALC4080. These chips support 24 bit/192kHz audio and deliver signal to noise ratios between 95 and 110 dB. That's clean enough for everyday listening with typical headphones or speakers.

The Benefits of Built In Audio

• Zero extra cost: Already included with your motherboard
• Simple setup: Works right away, usually without installing extra drivers
• No extra space needed: Doesn't take up a PCIe slot or desk space
• Good enough for most tasks: Handles music, movies, games, and calls well

Where Onboard Audio Falls Short

Because onboard audio sits on the motherboard near other components, it faces some limits:

• Electrical interference: The audio circuit sits close to the GPU, CPU, and RAM. These parts create electromagnetic interference that can add hiss or hum to your sound
• Weak headphone power: Most onboard audio delivers only 30-50mW. That's fine for earbuds and gaming headsets but not enough for quality headphones above 80 ohms
• Basic parts: Budget capacitors and amplifier chips can reduce audio detail and add distortion at high volumes
• Limited space: Motherboard makers have little room for audio parts, so they use smaller, cheaper components

What Does a Dedicated Sound Card Do?

A dedicated sound card is a separate piece of hardware made just for audio. It connects to your computer through a PCIe slot (internal card) or USB port (external unit). Because it's built for one job, it can include better parts and smarter design.

The main improvements come from three areas: a better DAC (Digital to Analog Converter), a stronger headphone amplifier, and distance from electrical interference inside the computer.

Sound Card Price Tiers

Key Differences That Affect Sound Quality

Signal to Noise Ratio (SNR)

SNR measures how much signal (the music or game audio you want) there is compared to noise (hiss, hum, static). It's measured in decibels (dB). Higher numbers mean cleaner sound.

• 90-100 dB: Budget onboard audio. Fine for casual use but you may hear hiss in quiet moments
• 100-110 dB: Good onboard audio. Clean enough for most people
• 110-120 dB: Quality sound cards. Very clean with no audible noise
• 120+ dB: Audiophile grade. Studio quality silence

The human ear can notice differences of about 3 dB. Moving from 100 dB onboard audio to a 120 dB sound card creates an obvious improvement in clarity.

Headphone Amplifier Power

This is one of the most overlooked issues. Headphone impedance, measured in ohms, tells you how much power headphones need. Most onboard audio only handles low impedance headphones well:

• 16-32 ohms: Earbuds, gaming headsets. Work fine with onboard audio
• 32-80 ohms: Entry level audiophile headphones. May work but won't reach full potential
• 80-300 ohms: Quality headphones like Beyerdynamic DT 770/880/990, Sennheiser HD 600 series. Need a sound card or amp
• 300-600 ohms: High end studio headphones. Definitely need dedicated amplification

When headphones don't get enough power, you'll notice low maximum volume, weak bass, and compressed dynamics where everything sounds flat.

DAC (Digital to Analog Converter) Quality

The DAC converts digital audio files into analog signals. Better DACs preserve more detail and create smoother, more natural sound. Key specs include:

• Bit depth: 16 bit is CD quality. 24 bit captures more detail. Both onboard and dedicated usually support 24 bit
• Sample rate: 44.1kHz is CD quality. 192kHz is studio quality. Higher rates can sound smoother
• DAC chip brand: Premium cards use ESS Sabre, AKM, or Burr Brown chips known for audio quality

Electrical Isolation

Onboard audio circuits sit millimeters away from the GPU, CPU, and power delivery systems. These create electromagnetic interference that can leak into the audio path as hiss, hum, or static.

Dedicated sound cards solve this two ways. Internal PCIe cards include metal shielding around sensitive parts. External USB DACs sit completely outside the computer case, away from all interference. This isolation creates a "blacker" background with no audible noise between sounds.

When Onboard Audio Makes More Sense

A dedicated sound card isn't always the right choice. Onboard audio works well for:

• Casual computer use: Web browsing, YouTube, Netflix, video calls
• Budget gaming: Using a gaming headset or basic speakers
• Low impedance gear: Earbuds, gaming headsets (16-32 ohms), wireless headphones
• Tight budgets: Money better spent on GPU or CPU upgrades
• Modern high end motherboards: Premium boards with ALC4080 or ALC1220 codecs rival budget sound cards

Why a Sound Card Might Not Help

Adding a sound card won't fix every audio problem. Keep these limits in mind:

• Bad source files: Compressed MP3s or low quality streams won't sound better with better hardware
• Cheap headphones or speakers: A $30 headset can't reveal details that quality hardware can
• USB headsets: These have their own built in DAC and bypass your computer's audio entirely
• Bluetooth audio: Wireless compression limits quality regardless of source

When a Sound Card Is Worth It

Certain situations benefit clearly from dedicated audio hardware:

• Quality headphone owners: If you own headphones costing $150 or more, especially high impedance models like Beyerdynamic, Sennheiser, or Audio Technica
• Competitive gamers: Virtual surround processing and cleaner positional audio help locate enemies by sound
• Music listeners: Fans of lossless FLAC or high res audio who notice compression artifacts
• Content creators: Musicians, podcasters, and streamers need quality microphone inputs and zero latency monitoring
• Home theater setups: Need optical or coaxial outputs for surround sound receivers
• Interference problems: If you hear hiss, static, or hum that changes with GPU load

Sound Card vs External DAC/Amp

External USB DACs and headphone amplifiers offer an alternative to internal sound cards. Here's how they compare:

External units work well for laptop users, people who switch between computers, or anyone who wants the cleanest possible signal. Internal cards suit desktop users who want gaming features and don't need portability.

Simple Decision Guide

Final Thoughts

Built in audio has improved a lot over the years. Modern motherboards with quality Realtek codecs deliver clean sound for everyday use. Most people genuinely don't need a dedicated sound card.

But if you've invested in quality headphones, if you hear annoying hiss or static, or if audio is important to your gaming or work, a dedicated sound card delivers real improvements. The $80-$150 range offers the best value for most enthusiasts, with clear upgrades in clarity, power, and features.

Start by thinking about your current setup honestly. If you're using quality headphones and they sound quiet or flat, onboard audio is likely holding them back. If you're using a $30 gaming headset, upgrade your headphones first, then consider a sound card later.