Why Video Editing Demands So Much From Your Computer
If you’ve ever tried Editing video on an older or underpowered computer you know the frustration of laggy playback, slow renders and frequent crashes or freezes.
Video editing, especially when working with modern codecs and high resolutions, puts tremendous strain on your system’s processor, memory, and storage.
So why is video editing is such a computationally intensive task that requires increasingly beefy hardware.
Massive Video File Sizes
The root cause boils down to the sheer amount of data that makes up video files in the age of high-definition, 4K and beyond.
An hour of 1080p video at a modest 24 frames per second and a bit rate of 10 Mbps requires around 4.5 GB of storage space.
Scale up to 4K (3840 x 2160) at 60 fps with a 50 Mbps bit rate and you’re looking at over 27 GB per hour of footage.
The data rates become astronomical when you get into 8K, higher Frame Rates and more complex encoding like 10-bit color depth.
All that data has to be read from your drive, decompressed, manipulated, re-encoded and written back out during the editing process.
That’s a staggering amount of information to process especially in real-time during playback and scrubbing through the timeline.
The Computational Complexity of Video Codecs
Speaking of codecs (encoder/decoder algorithms that compress and decompress video), modern options like H.264, H.265 (HEVC), VP9, and AV1 utilize incredibly complex techniques to squeeze maximum quality out of minimal file sizes.
They rely on resource-intensive processes like inter-frame encoding, motion vectors and transform coding.
When you edit a video clip the codec has to fully decompress every frame which requires a huge number of computations.
Applying effects, compositing, color grading and other processes pile on even more work for the CPU and GPU.
And when you’re done with your sequence the final render has to crunch through re-compressing every single frame using the same demanding codec.
The demands scale upwards for higher resolutions, bit depths and frame rates.
Codecs have also evolved over time to employ more advanced compression algorithms, trading greater efficiency for increased processing power required.
So you will have noticed I keep using the terms “compress” and “decompress.”
The term “compression” is in itself a bit of a red herring.
It gives the impression that data is somehow being squeezed into a smaller size but nothing could be further from the truth.
What is actually happening in-camera or recording device is that each image is being recorded, compared to previous images and later images (generally about 20 frames each way) and all repeated information is discarded.
That results in an enormous saving in the amount of data that ultimately forms the video files…BUT!
For playback, editing, scrubbing through the timeline and adding effects each frame has to be reconstructed using data from earlier and later frames.
The amount of work your computer has to do in order to achieve that is enormous.
If that’s a little difficult to understand then try this video for a bit more on compression:
Why So Much RAM?
While video processing taxes the CPU and GPU considerably available RAM is possibly the biggest constraint for video editing performance.
As a general rule, more RAM is always better when it comes to buttery smooth video editing.
When you import a clip into your video editing application it gets copied entirely into RAM to allow fast read access during editing.
Those multi-gigabyte file sizes we mentioned earlier?
They need to fit into your system’s memory alongside the video editing software itself, any attached media like graphics and audio, preview files, cached frames for real-time playback and scratch space for background rendering tasks.
If you run out of RAM while editing your system has to swap data between RAM and your storage drive, introducing extreme lag as it tries to shuffle information back and forth.
In the worst cases, you end up with dropped frames, crashes, and instability.
Most video editing programs recommend having at least 16 GB of RAM for 1080p work, 32 GB for 4K footage, and more for higher resolutions and frame rates.
The increased complexity of HDR video also consumes more memory during editing.
Storage Speeds Matter
While not as critical as a fast processor and ample RAM storage drive performance plays an important role in video editing.
With such enormous file sizes, being able to quickly read and write video data to and from your drives can eliminate bottlenecks and keep up with the demands of real-time editing and encoding.
Traditional hard disk drives (HDDs) are the cheapest option for sheer capacity per dollar but their spinning platters and mechanical read/write heads result in relatively slow transfer speeds.
HDDs are acceptable for storing footage offline but video editing directly from an HDD will feel incredibly sluggish.
For an optimal editing experience you’ll want solid-state drives (SSDs) that take advantage of ultra-fast flash memory with no moving parts.
Also bear in mind that your video editing software is sitting on top of the computer’s operating system and whatever that system is it has been developed to be working with SSDs in the current era.
The latest NVMe SSDs over a PCIe connection can achieve sequential read/write speeds over 7,000 MB/s.
That’s the performance you need to juggle multiple streams of 4K (or higher) video without skipping a beat.
It’s best to edit from and render videos directly to a fast internal or external SSD. You’ll want ample capacity too – video files add up quickly once you start accumulating multiple projects.
The GPU Accelerates Video Effects
While CPUs handle the core computations around decompression, processing, and encoding, the graphics processing unit (GPU) plays an increasingly crucial role in video editing.
Many of the effects, filters, compositing tricks and color processing in modern non-linear editing suites offload intensive tasks to the GPU to leverage its parallel processing power.
This goes double for editors working with 3D modeling, animation and motion graphics applications alongside their video editing needs.
Programs like PowerDirector, Filmora, Movavi, Pinnacle Studio and VideoStudio all take advantage of fast GPUs to accelerate their video processing workflows.
For graphics acceleration, most video editing programs rely on GPU-accelerated compute APIs provided by vendors like Nvidia (CUDA and OptiX) and AMD (Stream).
So having a fast, modern GPU designed for creative applications is a must for anyone looking to push the limits of video editing.
Future Video Standards Will Raise the Bar
Just when it seems like modern hardware is finally powerful enough to meet the demands of contemporary video editing, new standards emerge that once again increase the computational requirements.
These future formats increase resolutions, frame rates, dynamic ranges, and color accuracy—all while aiming to achieve greater compression efficiency.
8K video recording and delivery is already on the horizon, with resolutions up to 8192 x 4320 pixels—a staggering 33 megapixel count for each individual frame. Higher frame rates up to 120 fps are gaining traction to enable better motion clarity.
HDR formats with increased color depths and luminance ranges put greater strain on processing, memory, and bandwidth.
On top of that, new video codecs like the royalty-free AV1 have been engineered from the ground up to outperform existing standards through techniques like:
- More efficient entropy coding
- Enhanced predictions and motion estimation
- Frame partitioning and tiles for parallelization
- Support for video at higher resolutions, frame rates, and color depths
While AV1 achieves exceptional compression, it does so by drastically increasing computational complexity—around 7-15 times more intensive than VP9, depending on the quality setting.
The end result? Editing AV1 compressed 8K HDR video at 120 fps will absolutely demand the latest and greatest hardware, even after optimization and acceleration techniques.
Cutting-Edge Hardware for Modern Video Editing
As you can see, editing high-resolution, high-framerate video files requires systems with a multi-core processor in the latest generation, ample amounts of RAM, blazing-fast SSD storage, and a GPU optimized for video editing workloads.
The exact hardware required depends on your specific needs in terms of resolution, frame rates, effects usage, and efficiency demands (i.e. whether you can afford longer render times versus the cost of more horsepower).
As video technologies continue to evolve with higher resolutions, frame rates, dynamic ranges, and new compression algorithms, the hardware requirements will only increase.
Video editing has truly become one of the most demanding tasks for a computer, rivaling the needs of gaming, 3D animation, and scientific computing workloads.
Original post Why is Video Editing So Computer Resource Intensive?
