Weird VST performance tiny audio drop-outs

[epoch]

I've been doing some benchmarking and have found something strange in the way standalone Reason performs with VSTs on my system.

If I build a song only using REs, I can get the CPU meter to nearly 100% and don't experience any audio drop-outs. Just the GUI getting slower and slower with fewer frames per second. But the audio is rock solid until it starts to disintegrate as the CPU is completely maxed out. This is to be expected and so I rate the performance as impressive.

However, if I build a song only using VSTs, the CPU meter needs only to start touching a few bars (what appears to be only 25-30%) before I get the occasional audio drop-out where the audio just stops for a small moment before continuing. The GUI is still drawing fine at a decent FPS - and it still does this even if all VST plugin windows are closed.

I tried remaking the same projects using Reason 10.4 and it does the same there too. REs are rock solid. But if I use VSTs in a project then audio isn't stable all the time as CPU load increases; I get tiny drop outs reasonably frequently.

Is this a known performance issue with VSTs in Reason, or is this something particular to my system?

[DaveyG]

In Preferences-Audio make sure the "render using audio card buffer size" is checked.
Also play with those other performance settings.

[epoch]

In Preferences-Audio make sure the "render using audio card buffer size" is checked.
Also play with those other performance settings.

Already ensured that was checked.

Also tried with Hyper-Threading both Off and On. It makes no difference. I just get drop outs every now and again once I start pushing the system if there are VSTs in the rack. Like I said, using 100% REs gives very stable performance and no drop-outs. Even at high CPU usage the audio starts to disintegrate instead. But using only VSTs (and building a track out of only VSTs especially) creates these mini audio drop outs - even without any VST windows open.

I've tried at 512 samples and 1024 samples. Still no good.

I'm thinking it must be something in my system as surely someone else would have noticed this before me?

[Noise]

I always recommend checking the power savings settings in windows, check if it is in "balanced mode", it's a major issue for crackling sound. Set it to "ultimate performance"

[jam-s]

Also make sure the VSTs are actually activated as some occasionally just give out silence (or noise) every now and then when in demo mode.

[epoch]

Cheers for the replies!

I'm on Mac so the Windows power setting recommendation isn't something I can follow.

The VSTs are all fully authorised.

Anyway, earlier today I bit the bullet and bought Logic Pro X and I'm glad to report that it has no such issues when using the Audio Unit versions of the same plugins. Shame I can't get this kind of stability with third party plugins in Reason.

I was really hoping to use Reason as a VST host but it seems it just doesn't want to play ball in doing so reliably without audio dropouts on my machine. Will stick with Reason for 100% REs (which are rock solid) and can now use Logic for AUs plus the RRP if I fancy it.

Thanks all

[epoch]

I did some more tests and I think I've found a fix on my machine for this issue. Whilst Logic is great, I do much prefer Reason's workflow, so didn't want to stop looking to work out why this was happening. Here's what I found.

Firstly, my Mac can't go any further than El Capitan.

If I install all El Capitan updates, it includes the fix for Spectre/Meltdown which is in the kernel from Security Update 2018-001 onwards (the last update was 2018-004).

What I found is, if I extract the kernel from Security Update 2017-005 (the last not to have the Spectre/Meltdown fix in it) and put that in /System/Library/Kernels and then do an update caches and reboot, it gives me a much more solid VST performance in Reason in El Capitan, without the weird micro drop outs happening any more. Had to disable SIP to update system files btw.

I think on newer machines with fancier CPUs this mustn't be a problem but on my older machine and older CPU, VST performance just isn't very good at all when using the newer 'more secure' kernel. This machine isn't on the internet so it isn't at risk from running the older kernel code and now at least I've managed to try and squeeze as much performance out of it as I can.

Anyway, I thought I'd share my findings incase anyone else finds this thread and wonders why their older Mac has poor CPU performance when running VSTs inside Reason. It'll likely be Spectre/Meltdown mitigation within the OS kernel.

[Billy+]

I did some more tests and I think I've found a fix on my machine for this issue. Whilst Logic is great, I do much prefer Reason's workflow, so didn't want to stop looking to work out why this was happening. Here's what I found.

Firstly, my Mac can't go any further than El Capitan.

If I install all El Capitan updates, it includes the fix for Spectre/Meltdown which is in the kernel from Security Update 2018-001 onwards (the last update was 2018-004).

What I found is, if I extract the kernel from Security Update 2017-005 (the last not to have the Spectre/Meltdown fix in it) and put that in /System/Library/Kernels and then do an update caches and reboot, it gives me a much more solid VST performance in Reason in El Capitan, without the weird micro drop outs happening any more. Had to disable SIP to update system files btw.

I think on newer machines with fancier CPUs this mustn't be a problem but on my older machine and older CPU, VST performance just isn't very good at all when using the newer 'more secure' kernel. This machine isn't on the internet so it isn't at risk from running the older kernel code and now at least I've managed to try and squeeze as much performance out of it as I can.

Anyway, I thought I'd share my findings incase anyone else finds this thread and wonders why their older Mac has poor CPU performance when running VSTs inside Reason. It'll likely be Spectre/Meltdown mitigation within the OS kernel.

Do you know of a way that I can get hold of Logic for El Capitan as I would rather not upgrade even though I can, I was trying to figure out how to get Logic and run RRP to take advantage of Logics sequencer and midi vst support.

[epoch]

Do you know of a way that I can get hold of Logic for El Capitan as I would rather not upgrade even though I can, I was trying to figure out how to get Logic and run RRP to take advantage of Logics sequencer and midi vst support.

I followed the instructions here: http://www.audiomonk.org/forums/topic/h ... ing%20this

Had to use a MacBook Pro running a newer OS to be able to buy it first.