[VIDEO] CPU Performance vs. Real-Time Performance in Your DAW


Senior Member
And to the hardware purists out there - someone pointed out that EFI is used in place of BIOS these days. Yes, it is - but I'll probably be calling it BIOS for a long time to come :)
If you want to be really particular it is UEFI or (uEFI) Unified Extensible Firmware Interface) and yes I am sad enough to know that off-by-heart :/

For Macs until recently (I believe they now use the full specification) Apple only used custom-EFI, as they were only utilizing a substrate of the EFI standard

I do understand however that with Windows 8 they began to implement more and as of the release of Windows 10 they use the full spec to support Secure Boot for Windows with Bootcamp

Sad techy here, who lives in the basement ;)


Active Member
What an awesome video Richard!
Thanks for making this subject clear enough for thick headed guys like me to understand!


New Member
Still the best information on the subject !!! I saw the videos on youtube in the past, but want to thank the author again for the insight.

Unfortunately, in real life - unless you have the budget / time (or technician) to experiment - it's not so easy to implement.
1) You can't base serious decisions on specs only - that is if you (can) have real specs of all the subassemblies/parts and how they're integrated
2) Products are (dis)appearing continuously, and manufacturers change part sourcing / implementation during product lifecycles, etc.

The monitoring tools are a help - unfortunately windows-only afaik :(

BTW : willing to pay for a OS X realtime monitoring tool similar those mentioned in the article/videos !!


Senior Member
One of the best technical explanation videos I have ever seen! Hope the author will make more on other topics.

Regarding OS X macs, its important to understand that OS X uses an entirely different mechanism to handle low level drivers then windows. Windows uses something called Deferred Procedural Call (i.e., DPC), and it has to do with the fact that Windows operating system is interrupt driven. There are pros and cons to being interrupt driven, but one of the cons is this symptom called DPC latency. OS X does not use that mechanism at all. I'm not exactly sure right now what OS X does do, but it does not do DPC. So there is no point to worrying about whether your mac has high or low DPC latency since we don't have a DPC latency checker utility..its not relevant. There is no such thing as DPC in OSX. OS X works a little differently.

That being said... There actually is a built in command line utility in OS X for monitoring latencies... when I run it, they are all low enough to not cause any concerns...so I don't know what OS X is doing differently, but knock yourselves out..its called /usr/bin/latency. From the command line you can type 'man latency' to read more about it.

Much of this video is still extremely good information for musicians, regardless of whether you're using OS X or Windows, in terms of understanding that neither computer is an actual real time computer. It operates on buffers and gives an illusion of real time operation, with buffer latency in the sound card being the thing that enables that to happen. We make music in real time, but the computer is processing things and timesharing different components of the system. Very well presented video here and applicable to both platforms, except for the DPC section.
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New Member
Amazing! Thank you so much for this. There has been talk of modifying one's RAM speed in this thread - but I watched the entire video, and saw no such thing on that topic.

Could someone enlighten me as to the "slow your RAM" theory?


Workstation nerd deluxe
RAM speed is not an issue for audio. New Ryzen CPU's may benefit from it but the effect for realtime audio is marginal.


Senior Member
Finally got around to Watching this. Totally Great! It explains why my 10 year old machine still runs circles around a lot of other machines. The DPC latency is way lower on that machine than my other newer ones.

Great reference to start building my new DAW.


Senior Member
Again, pointing out that several tests from multiple users (including a long Gearslutz thread containing Logic project to test RTP) and a Sound On Sound article, etc, disproves the theory that multiple cores does not increases RTP. This is especially true for script heavy Kontakt patches that uses multi-core processing to handle non-audio related instructions. Also, this video is even less actual today when plugin and DAW manufacturers have optimized their software for multicore use.

Would Apple and all specialized PC DAW Building companies lie about this without anyone discovering it? No.

Are there other factors that can affect RTP? Yes, there is. But disregarding those, multiple cores significantly increases Real Time Performance as long as the system doesn't have any other problems.

I linked the SOS article several years ago:

Also this, a mix between old and new stats:

Test are conclusive.

Also, as several other in this thread has pointed out: This video has nothing to do with OSX. I did an extensive test with Mainstage when programming sounds for a musical theatre show last year, that concluded that Kontakt inside Mainstage (running single core because of multi-core utilization conflicts between Mainstage and Kontakt) increased CPU usage by double rather than running Kontakt in multi core outside Mainstage. With the exact same patches. This also disproves the "multi core doesn't affect performance theory, and Mainstage is very realtime sensitive since it's live playback. This was confirmed on 4 different systems.

I don't agree with the conclusion of this video, and there are plenty of sources to back that up. I can't say what the video author's specific template does for this theory, but in all my cases of building orchestral setups throughout the years, there simply one conclusion:

More Cores = Better Performance.
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Senior Member
unless you need low latency live, especially with a dense plugin stack or a really powerful synth plugin then it doesn’t.
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