Why does ASIO buffer size affect MHarmonizerMB quality?

[Awats]

I use Cakewalk By Bandlab (on the latest version) and when using the MHarmonizerMB, I noticed I have to run the ASIO buffer size up to about 128 or the harmonizer breaks up and gets choppy. Setting ASIO to 2048 makes it totally unusable. It's grinding rocks. Anything beyond 512 starts to crap out. It's not uncommon to run large buffers during playback but with the harmonizer, it limits that to smaller buffers.

I also notice that when I switch ASIO from 128 or so to 2048 from within Cakewalk it takes at least 30 seconds for Cakewalk to return. It's long enough that Windows says it's not responding but eventually comes back. Maybe this is a Cakewalk specific question but figured I ask here.

The reason I ask is:

1. Why does the buffer size affect playback quality?
2. Are there other specific setting I should be using elsewhere to maintain the harmonizer smoothness? When it's smooth, it's great but it seems little things make it start getting choppy and distorted.

I only stumbled on the ASIO buffer size issue because the harmonizer sounded really choppy and I started checking EVERYTHING to figure out why. Overall, the song isn't really taxing the i7 processor. It's related to the buffer or something I haven't figured out.

I've tried both a Presonus Audiobox iTwo and a M-Audio Quad. Same results with the choppiness.

[Awats]

I read the last section of the manual and I get what it is saying but not the relationship to the ASIO buffer directly.

Anyone? Beuller?

[MeldaProduction]

Please send us the project via info@meldaproduction.com or something, also mention what kind of computer you have. It looks like CPU overloads, so your computer apparently cannot handle that anymore, but it's odd, since it should be the other way around. Please also try a different DAW, may be it's a problem in this Bandlab thingy.

[Awats]

I’ll put something together but there is zero indication anywhere the I7 is overloaded. All cores are running. Core 1 might spike to 50% here and there. Plenty of memory too. Cakewalk is pretty well known in the DAW world. But loading a different DAW isn’t really practical.

As long as I stay away from 512 to 2048 it’s fine. Cakewalk starts to have issues itself at 64 or smaller on larger projects.
For playback I’m stuck at 128 or 256.

HP 500
I7 3.3GHz
16GB
Presonus iTwo
No other apps are running