Problem with U-He plugins at high audio buffer settings

[KarmaFunkarma]

Obviously, the 10.3 release helped performance greatly, but I found a problem unique to U-He plugins such as Repro 5, Bazille, Hive, Zebra, Zebra HZ, etc, where at higher buffer settings the audio craps out. At 4096, this can happen with even a single instance of one of these plugins. Other plugins that I tested from different companies such as Serum, SynthMaster 1, OmniSphere, various Arturia plugins, Reaktor, etc, do not have the problem. Also, the problem appears to be much more of an issue with the U-He plugins on polyphonic patches as opposed to single note patches. Interestingly, the problem is sort of inverted with HT on/off.

As an example, here's a breakdown of how a song with 4 instances of Repro 5 and one instance each of Omnisphere and SynthMaster1 performs.

256 HT On - Plays Smoothly
256 HT Off - Plays slow with lots of crackles and stutter - DSP meter Red

512 HT On - Plays Smoothly
512 HT Off - Plays slow with lots of crackles and stutter - DSP meter Red

1024 HT On - Plays Smoothly
1024 HT Off - Plays slow with lots of crackles and stutter - DSP meter Red

2048 HT On - No audio with short bursts of sound every few seconds
2048 HT Off - Plays slightly slow, sound stutters constantly almost like talking into a fan

4096 HT On - No audio at all, but the meters on screen are moving
4096 HT Off - Plays slightly slow, sounds like talking into a fan running at a slower speed than what 2048 sounds like.


Reported these details in the beta bug ticket system during beta testing, but never heard back from PH after an initial question about HT settings.

Anyone else with the U-He plugs notice this or have a solution?
MacOS 10.13.6 - Focusrite USB 2i2 - 16GB Ram - 2.2Ghz Core i7

[tanni]

Hi,
Im on Windows 7 (64 bit) i7 cpu 3.4 Ghz, 32 GB RAM and there are no problems like you have.
I have Hive, Zebra, Repro and all runs smooth at the same time.
I have the Base Latency on the uhe synths all on 16 samples (in the Preferences of the uhe synths).

[qr9000]

I don't know if this has been resolved, but I'm experiencing a similar issue with Diva, particularly with polyphonic patches. I am also running OSX (10.14) and using an external soundcard (UMC 404HD).

It's difficult to describe, but it sounds like VST is struggling to emulate the beating sound of detuned oscillators. Whenever I play multiple notes at a time, there are a lot of artifacts, and the sound gets quite muddy. This happens to me regardless of buffer size, and with DIVA in draft, fast, great or divine modes.

On a hunch, I tried running the same MIDI through the same patch in Garageband, and the difference was night and day.

[Boombastix]

I only have Diva - set to multicore (helps a lot) and 16 samples.
I Reason I have HT off, multicore on, ASIO buffer at 512.
Works fine in Win 10 and i7 at 3.4GHz.

But mind you U-he is CPU HUNGRY, and in Diva the voices (stack) amount setting eats up a lot, and of course polyphony too as you almost double the work load.
With a CPU of 2.2GHz, nah, you probably have things a bit under powered.