Does having multiple monitors make video calls slower?

Sometimes. Running two or three monitors increases GPU memory bandwidth usage and can add to CPU load if the system is already near its limit. If you are struggling on a call, try disabling a secondary monitor temporarily to see if it helps.

Why does my fan go crazy the moment I start a video call?

The fan ramps up because the CPU and sometimes GPU workload spikes sharply the moment encoding starts. This is normal behavior. If the fan is consistently loud for the entire call, it means the system is sustaining high thermal load, which points back to a CPU or thermal paste issue on older machines.

Can a VPN slow down my video calls?

Yes. A VPN routes your traffic through an additional server and encrypts it on the fly, which adds latency and can cut effective upload throughput. Try disconnecting the VPN during a test call to see if performance improves. If it does, your VPN server location or protocol may need adjusting.

My internet speed test looks fine but calls are still choppy. What else could it be?

Speed is not the only factor. Packet loss and jitter matter more for real-time audio and video than raw megabits. Run a ping test to your router and to a public server like 8.8.8.8 and look for inconsistent round-trip times or dropped packets, which a standard speed test will not catch.

Why Does My PC Run Fine Alone but Slow on a Video Call?

TL;DR: Video calls combine camera, microphone, encoder, network, and display workloads simultaneously. Your PC may handle each one fine in isolation, but stack them together and a weak link, usually CPU encoding, RAM bandwidth, or upload speed, becomes the bottleneck. Identify which resource is spiking, then fix that specific thing.

What You Need

Windows Task Manager open during a call (Ctrl + Shift + Esc)
A speed test tool like Fast.com or Speedtest by Ookla that shows upload speed
About 10 minutes to run through the diagnostic steps below
Optionally, a second device to monitor while calling from the first

Step 1: Understand Why Video Calls Are Heavier Than They Look

When you are just browsing or working in a document, your CPU, RAM, and network handle one job at a time. A video call forces all of them to sprint together.

Here is what is happening every second you are on that call:

CPU encodes your outgoing video in real time (software encoding is brutal on older chips)
RAM buffers incoming and outgoing audio and video streams
Network uploads your encoded video while downloading everyone else's
GPU (sometimes) handles decode on the receiving end
Webcam driver adds a constant interrupt load

One weak link tanks the whole experience. That is why the PC that feels fast for everything else suddenly chokes the moment Zoom or Teams opens.

Monitoring system resources in Task Manager during a live video call reveals which hardware component is causing the slowdown.

Step 2: Check CPU Usage During the Call

Open Task Manager (Ctrl + Shift + Esc), click the Performance tab, and watch the CPU graph while on a call.

Above 80% sustained: CPU is your bottleneck. The video encoder is eating your headroom.
Spikes to 100% on every keyframe: Same problem. Keyframes are full-image snapshots the encoder sends periodically, and they are expensive.
Below 60%: CPU is probably not the issue. Move to the next step.

If CPU is the culprit, try lowering your video resolution inside the app settings. Dropping from 1080p to 720p can cut encoding load by roughly half. Closing background apps that use the CPU (browser tabs with video, Spotify, cloud sync) also helps immediately.

Step 3: Check RAM Usage

Still in Task Manager, click the Memory section. Look at the "In Use" bar.

If you are at or near the top of your installed RAM, Windows is using the page file on your drive as overflow. That is dramatically slower than real RAM and will make everything feel sluggish.
8 GB is tight for a video call running alongside a browser, email, and Slack. 16 GB is the practical minimum for smooth multitasking in 2024 and beyond.

Short-term fix: close everything except the call app. Longer fix: add RAM. It is one of the cheapest performance upgrades available.

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Step 4: Test Your Upload Speed

This one trips people up constantly. Most home internet packages are asymmetric: fast download, slow upload. Video calls primarily consume upload bandwidth because you are sending your video stream outbound.

Run a speed test at Fast.com and look at the upload number.

Platform	Minimum Upload	Recommended Upload (HD)
Zoom	1 Mbps	3 Mbps
Microsoft Teams	1.5 Mbps	4 Mbps
Google Meet	1 Mbps	3.2 Mbps

If you are on Wi-Fi, the problem may not be your plan at all. A congested 2.4 GHz channel or distance from the router can cut effective upload speed significantly. Try an ethernet cable and re-test. The difference is often dramatic.

Step 5: Check What the GPU Is Doing

In Task Manager, find the GPU section. Look at "Video Encode" and "Video Decode" usage specifically, not just the overall GPU load.

Modern apps like Teams and Zoom can offload encoding to the GPU hardware encoder (NVENC on NVIDIA, Quick Sync on Intel, AMF on AMD). If this is working, your CPU will be noticeably more free.

If your GPU encode usage is near zero and CPU is spiking, hardware encoding may be disabled or unsupported by your hardware. Check the app's advanced video settings and look for a hardware acceleration toggle. Enabling it can be a big win on systems with a dedicated GPU.

Step 6: Check Your Webcam and Driver Load

Some webcams, especially cheaper models, run uncompressed video over USB and force the CPU to compress that raw stream entirely in software. Higher-end webcams compress video onboard and send a smaller data stream.

Also check that your webcam driver is current. An outdated driver can cause repeated USB interrupts that spike CPU usage unpredictably. Device Manager, right-click the camera, update driver.

Common Mistakes

Running too many browser tabs during a call. Browser tabs with video embeds or live widgets consume CPU even when minimized. Close them.

Assuming Wi-Fi is as fast as ethernet. Wi-Fi speed tests in ideal conditions look fine. Under real call conditions, interference and packet loss make it worse. Always test upload while on Wi-Fi at your actual calling location.

Blaming the app when the hardware is the issue. Reinstalling Zoom will not fix a 4-core laptop from 2015 trying to encode 1080p video.

Ignoring background updates. Windows Update, antivirus scans, and cloud backup jobs frequently kick off during business hours and fight the call for CPU time. Schedule these for off-hours.

Using a USB hub for the webcam. Shared USB bandwidth on a passive hub can throttle the camera feed. Plug the webcam directly into a rear USB port on the motherboard if possible.

Bottom Line

Your PC is not randomly slow during video calls. It is hitting a specific ceiling, CPU encoding, RAM capacity, upload speed, or a driver issue, and the diagnostic steps above will tell you exactly which one. Fix that one thing and the experience changes immediately.

If you run through all of this and the PC is still struggling, the hardware may genuinely be at its limit. A RAM upgrade, a faster router connection, or in some cases a CPU or full machine refresh is the real answer. The team at Fix My PC Store on Okeechobee Boulevard can run a full performance check and tell you whether an upgrade fixes it or whether it is something else. Remote support is also available if you want someone to look at what is happening inside the machine without bringing it in.

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