I'm about to upgrade my CPU, and so wanted to do a little not-very-scientific benchmark just to get an idea how my new machine will perform relative to my current one. I observed some really puzzling results and I hope someone here can maybe help me understand what is happening. I'm currently running an Intel Core i7-4790K (no overlocking), and not that it should matter, but my audio interface is a Focusrite Scarlett 2i4, set at 44.1Khz/128 bytes buffer size.
I created a Zebra2 patch that's just uses all four oscillators, set to 11 voices each, and then routed through a couple of effects, to which I then fed a 16-note chord. I've done this test in both Ableton Live 10 and Cubase 10.5 Pro, and the results are similar.
With one instance of Zebra, I get a lot of audible crackling. With two instances, I get a little less, and by the time I get to three instances, everything sounds perfect. I can continue adding instances until I get to about 12-13, before I start to hear any audio distortions.(this is at 128 buffer size. I can get 3-4 more going at 512 before it becomes an issue).
I have a theory that makes me wonder if this could be related to the CPU clock speed scaling on my Intel CPU. I don't know if anyone else has ever observed something like this, but I find it really odd that one instances causes such a problem, but many instances don't (at least not until I actually start to max out my CPU's capacity).
Question about CPU usage
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- KVRist
- 48 posts since 24 Oct, 2011 from USA
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tasmaniandevil tasmaniandevil https://www.kvraudio.com/forum/memberlist.php?mode=viewprofile&u=62450
- KVRAF
- 2171 posts since 22 Mar, 2005 from a planet called u-he
Automatic clock scaling can cause performance issues, especially when it comes to audio production.
We had a few support issues over the years where it turned out that this feature was the source of the problem.
A better option might be to switch to a high performance power profile while working with the host, and then back to a profile with automatic clock scaling afterwards.
We had a few support issues over the years where it turned out that this feature was the source of the problem.
A better option might be to switch to a high performance power profile while working with the host, and then back to a profile with automatic clock scaling afterwards.
That QA guy from planet u-he.
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- Banned
- 207 posts since 13 Jul, 2020
I have same CPU (Core i7 4790k), but i have turned off CPU clock scaling and always runing on turbo mode. Zebra 2 gives me no issues, in fact its one of least CPU heavy plugins along with Dune 3 and Viper. Zebra can get heavier and on par with some modern VSTS if you are using XMF filters.
Last edited by the.new.me on Sat Sep 19, 2020 4:38 am, edited 1 time in total.
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- KVRist
- Topic Starter
- 48 posts since 24 Oct, 2011 from USA
Thanks for the replies, guys. I just finished upgrading the motherboard/CPU to an i7-10700K, and am not seeing that issue any more. I can run 1 instance, or 20+ and it sounds fine. Very weird.
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- Banned
- 207 posts since 13 Jul, 2020
Congratulations with the new buy! I was able to run ~60x instances of Zebra2 with 2 oscillators with 11 unison and xcite filter playing 4 chord note on 4790k (256samples/6ms) so you should triple double thatDNeal wrote: Sat Sep 19, 2020 12:22 am Thanks for the replies, guys. I just finished upgrading the motherboard/CPU to an i7-10700K, and am not seeing that issue any more. I can run 1 instance, or 20+ and it sounds fine. Very weird.
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- KVRAF
- 24442 posts since 7 Jan, 2009 from Croatia
Yes, absolutely disable SpeedStep and core parking (google how to), and make sure all the cores run at the Turbo speed in UEFI.