Why Is My REAPER So Slow? (Lagging, Glitching, Stuttering)

In this article, we will explore why REAPER might become slow and methods to treat the problems.

REAPER is one of the lightest DAWs available. So, technically, it should run flawlessly on most modern computers. However, the DAW offers myriads of settings and controls, making it confusing for new users to optimize it for their system. Hence, I will describe the important options and how they affect your production to help you better understand REAPER.

I’ve formatted this article to cover broad topics like computer settings first with more specific issues later. So, if you’ve already ensured your computer is optimized for music production, you can skip to the later sections. Without further ado, let’s look into the first issue:

Computer Optimization

Properly optimizing your computer is essential for your DAW to run smoothly. This process includes selecting appropriate hardware, drivers, and settings. Furthermore, some background processes and add-on software negatively impact your REAPER’s performance. Such applications, including antivirus, drive protection, intensive backup software, etc., should be disabled or removed.

PCs running on Windows and Linux typically require more optimization than Mac computers since they offer more customization and backward compatibility. However, this article will focus on Windows and macOS. Unless otherwise noted, the screenshots and steps below should be near-identical on both operating systems. Once we’re done with the steps for optimization, we’ll mostly focus on REAPER’s preferences page.

Optimizing Your Windows PC

A basic music production PC should have at least four cores, a 3.0 GHz boosted CPU clock, 8 GB RAM, and an SSD. However, it’s possible to use REAPER to produce music with much less, although you’ll have to be strategic in how you produce and mix. I started using REAPER on a Core2 Duo CPU (2 cores, 2.4 GHz) and 4 GB RAM. I used CPU-friendly plugins and froze any track that used too much CPU. So, it is possible to make music on a potato!

However, whether you’re using an old computer or the latest release, optimizing your PC greatly helps improve your overall experience. Let’s check out some of the steps for PC optimization:

1. Open the Task Manager, go to the Startup tab, and disable any app you don’t need when your PC boots up. I have disabled apps like Cortana, Xbox, Skype, Teams, Messenger, etc., since I don’t use them. I recommend enabling the Security Health Tray, your audio interface’s application, and any cloud storage/backup.
   
2. Use Windows Defender but uninstall any third-party antivirus software. Defender is enough for most users, and it uses the least amount of CPU.
3. Uninstall any unwanted software and keep your Windows and drivers updated.
4. Remove unnecessary files using Disk Cleanup. You can also check for disk errors occasionally by opening the properties of your hard drive partitions and clicking on the Tools tab. Similarly, REAPER lets you remove unnecessary audio files by clicking on Files > Clean current project directory. However, make sure the project uses a subdirectory before using this feature. If the project doesn’t use a subdirectory, the feature can delete media files that belong to other projects.
   
5. Open Control Panel and search for Power Options. Click “Change plan settings” for whichever one you’re using, and click “Change advanced power settings.” Next, under Hard Disk, change “Turn off hard disk after” to at least 20 minutes or to 0 minutes to disable the feature. Find “Processor power management” and change the “Minimum processor state” to 100%. Doing so disables core parking and allows you to use the full potential of your CPU. And finally, go to “USB settings” and change the “USB selective suspend setting” to disabled.
   

Optimizing Your Mac Computer

A Mac computer generally requires fewer customizations than a Windows PC since macOS prioritizes current performance over backward compatibility and doesn’t have to cater to various hardware. Further, Apple builds Mac computers using the latest hardware components, ensuring smoother operation. However, you can still take optimization measures to ensure your computer is fit for music production. Several of them are in the System Preferences. So, make sure you have the page opened before going through these steps:

1. Click on the Siri icon. Enable the Disable Ask Siri option to prevent unwanted interruptions during recording sessions. Furthermore, doing so will save some CPU resources.
2. Extensions are generally alright to leave as they are. However, you can disable customized extensions to get a performance boost.
3. Open Users & Groups, select Login Items and remove unwanted startup items.
4. Open the App Store and go to its Settings page. Disable Automatic Updates to prevent sudden incompatibility with your installed plugins and REAPER. Furthermore, ensure all your installed software is compatible with the new update before manually updating your Mac.
5. Keep at least 20% of your Startup Disk empty so your computer can work properly. The fuller the system drive is, the slower the performance of your Mac. So, try removing files you don’t need using the Review Files feature. You can find it by clicking on the Apple menu, selecting “About this Mac,” and opening Storage.
6. Remove any third-party antivirus you have installed. Mac computers already have built-in antivirus protections called Gatekeeper, Notarization, and XProtect. Furthermore, it also has a malware removal tool. However, if you keep Gatekeeper disabled to install unsigned apps, you might want a third-party antivirus like Bitdefender or Norton. Make sure you disable it during recording sessions, though.

Audio Driver

Symptoms:

• Stuttering sound even when REAPER’s Performance Meter (found under View) shows no significant load.
• Constant stuttering rather than lagging or glitching occasionally.

Audio driver issues plague Windows computers, particularly because of the operating system’s backward compatibility. It uses default drivers that could be from the 90s to ensure all software plays audio correctly. Furthermore, REAPER offers multiple audio drivers to maintain Windows’ philosophy.

Currently, there are two driver types you should bear in mind:

• ASIO
  ASIO (Audio Stream Input/Output) is an audio interface driver protocol that bypasses Windows’ traditional DirectSound signal path. While DirectSound offers a variety of features for consumers, professional users do not benefit from it because it increases the latency and adds an intermediary between the DAW and the audio interface. Hence, every audio interface by a major brand ships with a proprietary ASIO driver that REAPER and other DAWs recognize. This driver offers the best performance and is the first choice.
  Note that the free driver ASIO4All, which you might have installed on your PC, is not a real ASIO driver. It’s a WASAPI driver wrapped as an ASIO driver, which lowers the performance of the prior. However, it’s a good alternative for DAWs other than REAPER if they do not support WASAPI directly.
• WASAPI
  WASAPI (Windows Audio Session API) is Microsoft’s proprietary protocol to allow direct access to the audio interface or motherboard’s audio chip. It is only available in Windows Vista and above, offering close performance to ASIO. So, if you do not own an audio interface, WASAPI should be your choice. Likewise, if your audio interface or sound card lacks a supported ASIO driver, you should use WASAPI.
  Furthermore, WASAPI offers an exclusive mode and a shared mode. I recommend using the exclusive mode, but if you want to use other media players or browsers alongside REAPER, use the shared mode. There are also a couple of other related modes, but they’re beyond the scope of this article. So, please refer to the manual for those.

Let’s check out how to change the audio driver in REAPER:

1. Click on Options and open Preferences. You can also press Ctrl + P for Windows and Command + , (comma) for macOS.
2. Find Devices under Audio.
   
3. From the Audio System drop-down menu, select ASIO or WASAPI as needed.
   

Processing Time/Buffer

Symptoms:

• Crackling noise, particularly when more instruments play together, or more effect plugins are working simultaneously.
• Soloing a track or disabling a few plugins gets rid of the crackling.

The buffer is the time the DAW allows the CPU to process the audio calculations. The calculations include playing back audio files, generating sounds using synths, processing sounds with effect plugins, summing them, and playing them through your speakers/headphones. So, when we add more tracks or CPU-intensive plugins, the computer will require either more time to process them or a faster processing speed (CPU speed).

Increasing the buffer size in REAPER allows your computer more time to process the calculations. Doing so will also affect real-time processes like playing instruments live. So, I recommend keeping the buffer size low while recording live and only increasing it for mixing. Let’s check out how to change the buffer size in REAPER:

1. Click on Options and open Preferences. You can also press Ctrl + P for Windows and Command + , (comma) for macOS.
2. Find Devices under Audio.
   
3. Change the Request Block Size or Block Size value to a multiple of 2. Here’s my recommendation:
   
   • Use 64 or 128 for a live performance to get the least latency.
   • Use 256 for live recordings (with several tracks accompanying you).
   • Use 512 or 1024 for mixing. You can also try 512 for live recordings since it can have an acceptable latency for live playing.

Sample Rate

Symptoms:

• A sample rate higher than the computer can handle will result in similar crackling and stuttering as the lack of block/buffer size.
• In the case of WASAPI, using a sample rate incompatible with your PC’s current default will cause REAPER to refuse playback. Nothing will happen when you press play, even though all other functionalities and playback in other media players seem fine.

The sample rate is the number of times an analog waveform is sampled per second for digital interpretation. It determines the highest frequency possible to be recorded or played in a project file. However, this highest frequency, or Nyquist frequency, is half the actual sample rate due to the Nyquist-Shannon sampling theorem, which helps avoid aliasing (frequency overlap). Suffice it to say that if you use 48 kHz as your sample rate, the highest frequency possible to generate will be 24 kHz. And since 24 kHz is well above our hearing range (20 Hz – 20 kHz), a 48 kHz or 44.1 kHz sample rate is an excellent choice.

44.1 kHz is the CD standard, whereas 48 kHz is the video and broadcasting standard. Most of the music produced nowadays is being streamed and uploaded as videos. So, it’s often a better idea to stick to 48 kHz. Converting the 48 kHz audio file to a 44.1 kHz file for CD distribution or certain streaming platforms will result in no quality loss, whereas the same cannot be said for vice versa.

Some people use sample rates like 96 kHz or even 192 kHz in hopes of better audio quality. Unfortunately, all that will do is annihilate the CPU resources, forcing the computer to process twice or four times as much information as when using a sensible sample rate. So, follow the subsequent steps to make sure you’re using the standard sample rates:

1. Click on Options and open Preferences. You can also press Ctrl + P for Windows and Command + , (comma) for macOS.
2. Find Devices under Audio.
   
3. Change the Request Sample Rate (ASIO) or Samplerate (WASAPI) value to what you want. Type 44100 for 44.1 kHz and 48000 for 48 kHz.
   

Audio Buffering & Multiprocessing

Symptoms of Audio Buffering issues:

• REAPER appears to glitch and stutter faster or with fewer instruments and effect plugins than some other DAWs.
• REAPER glitches when you import and play media (audio or video files) from a certain hard drive.

Symptoms of Multiprocessing issues:

• The Task Manager or REAPER’s Performance Meter shows no significant CPU load, but REAPER keeps stuttering and glitching.
• REAPER starts stuttering when you use folder tracks or sends.

Audio buffering allows REAPER to preload media files in your computer’s RAM instead of streaming directly from your storage drives. This process is especially necessary for computers without a fast SSD and if you’re loading files with high bitrate (due to high sample rate, bit depth, or video resolution). However, too much audio buffering causes a lag in your lag between the moment you press play and the time it starts playing. There might also be lags in your plugin’s visuals. So, it’s important to have a balance that increases your computer’s performance while maintaining usability.

Let’s check out how to set the audio buffering settings:

1. Click on Options and open Preferences. You can also press Ctrl + P for Windows and Command + , (comma) for macOS.
2. Find Buffering under Audio.
   
3. Change the Media Buffer Size as required. If REAPER plays fine but then stutters when it reaches audio clips or the middle of an audio clip, try increasing the Media Buffer Size. Conversely, if REAPER lags and doesn’t start playing when you press play, try decreasing the Media Buffer Size. The default value is 1200ms.
   
4. Enable “Disable media buffering for tracks with open MIDI editors.”

Note that none of the above will have much effect if you use a high-RPM hard drive or an SSD.

Multiprocessing allows REAPER to utilize multiple CPU cores or threads to process each plugin. It reduces real-time CPU usage, and you can find its settings on the Buffering preferences page. However, REAPER disables some multiprocessing features to decrease live audio latency. Unfortunately, it creates an imbalance in the CPU cores and causes even a good CPU to stutter and crackle. I’ve noticed it, especially when using folder tracks or multiple sends. It’s the most common reason REAPER appears unable to host many plugins, complicated routings, or have a strange response to the Task Manager or Activity Monitor’s CPU readings.

Here’s how you can fix this issue:

1. Click on Options and open Preferences. You can also press Ctrl + P for Windows and Command + , (comma) for macOS.
2. Find Buffering under Audio.
   
3. Enable Anticipative FX Processing. This feature processes audio plugins to achieve a smoother performance before they start playing.
4. Enable “Allow on tracks without FX” to reduce the buffer size greatly for lower latency during live performance. Otherwise, keep it disabled.
5. Make sure “Allow on tracks with open MIDI editors” is disabled. Enabling it will cause a lag between the time you click notes in the MIDI editor and when they play. Although, it may be useful if your CPU is awfully overworked and you’re willing to tolerate the lag for reduced stuttering and glitches.
6. Enable “Allow live FX multiprocessing on.” The box next to this setting allows you to type in how many threads you want to utilize. However, I recommend typing the number of threads your CPU has rather than anything below it. On Windows, you can find the number of threads your CPU has by opening the Task Manager, going to Performance, clicking on CPU, and checking out the Logical Processors number. Similarly, on macOS, open the Apple menu, click About This Mac, and, under Overview, click on System Report. Copy the processor’s name into a search engine and look up its threads.

The last setting greatly improves REAPER’s performance, especially if you are experiencing stuttering and glitches despite having no substantial CPU usage.

Understanding The Performance Meter

The Performance Meter is a tool inside REAPER that allows you to check the usage of various resources on your computer. You can open it by going to View and clicking on Performance Meter.

The Performance Meter shows four important measurements: disk use, CPU use, RAM usage, and GPU use. You might have to right-click on the Performance Meter page and confirm they are set to display on the page.

Let’s go over each of the items and how they may be helpful:

• Disk Use
  This feature shows how much data your hard drive or SSD writes or reads per second. If any stuttering or glitching occurs when one of the “Disk read” or “Disk write” numbers go high, you should consider two things: replace your drive because it might be failing or your media has a high bitrate. You should increase Audio Buffering for the latter.
• CPU Use
  The CPU monitor in REAPER shows you the total CPU load, the real-time CPU (RT CPU) load, the CPU used by FX, and the CPU used by media items. Among these, the real-time CPU usage is the most important. Similarly, the latter two are also noteworthy. Furthermore, the Performance Meter also shows the CPU load of each track on a list. This feature is neat for recognizing problematic tracks.
  If REAPER is stuttering while the total CPU load is nowhere close to 100% and the RT CPU load spikes whenever it stutters, follow my steps for Multiprocessing. Similarly, if you notice the FX CPU load is spiking, look for which track has the highest FX CPU load. Then, you can either freeze that track or replace the plugin.
• RAM Usage
  Performance Meter can either show the used RAM or free RAM, which you can select by right-clicking over the page. You shouldn’t have a problem with RAMs if you have a decent amount. However, if your RAM is small, keep an eye on this number to help you decide if you need a RAM upgrade or to freeze some tracks.
• GPU Use
  The GPU usage is called Video Load in the Performance Meter. It stays idle unless you load a video file into REAPER. So, it shouldn’t be a bother if you have a basic, dedicated graphics card.

Conclusion

In this article, we’ve covered the most common reasons REAPER might crackle or stutter while playing. I hope the “Symptoms” lists help you find the correct reason quicker. Furthermore, I hope they prepare you for any future surprises you might encounter.

While REAPER prides itself on being light on the CPU, some of its settings might make it appear the opposite. For example, many REAPER users complain about its inability to have several folder tracks without causing a CPU strain like other DAWs. People don’t realize that REAPER treats its folder tracks as parent sends, which uses real-time CPU processing. And if you don’t set up Multiprocessing as I’ve described, it will use only one core of your CPU and cause an imbalance.

Similarly, users without an audio interface often have a hard time producing music. REAPER is one of the very few DAWs that natively support WASAPI. So, switching to WASAPI from wrappers like ASIO4All or Steinberg’s Generic Low Latency ASIO Driver will greatly improve your computer’s performance compared to other DAWs.

I hope you find this article helpful. Happy music-making!

K. M. Joshi

K. M. Joshi is a multi-award-winning composer and sound designer, specializing in film, game, and TV audio. He enjoys making cinematic music, rock, blues, and electronica. Read more..