Reaper: lowering latency. Better drive? Interface? Something else?

fretmeister

I have Reaper and my Neural / Helix VST all on an internal SSD that is also my OS drive.
At the moment my projects are run from an external spinning rust 2TB HDD via USB2.

According to Reaper I have 6.5ms latency. Which is not bad - about the same as a halfway decent wireless system. I have not tweaked any Reaper settings - they are whatever default is.

Would I see an improvement if I ran the projects from a USB3 SSD instead?

Would an updated interface be a better bet? Mine is a 1st Gen Focusrite Scarlett 2i4


PC specs are:

Win10 Pro

Processor: Intel Core i5-6600K Skylake CPU, 4 Cores, 3.5 - 3.9GHz
Overclocking: Overclock my CPU by up to 20%
Case: Zalman Z11 NEO Case - Black

CPU Cooler: Corsair Hydro H55 CPU Cooler
Thermal Paste: Prolimatech PK-3 Nano Particle Thermal Paste
Case Cooling: Additional Cooling Fans Upgrade Pack
Motherboard: Asus Z170-K Motherboard
Memory: 32GB DDR4 2133MHz Memory 
Graphics Card: NVIDIA GeForce GTX 970 4GB Graphics Card
OS Drive: 128GB Samsung SM951 M.2 PCIe Solid State Drive

Secondary Hard Drive: Seagate 1TB SSHD Hybrid Drive

Power Supply: Aerocool 80 PLUS 600W PSU

goldtop

RME. Not sure drive swapping when you already have 32GB RAM is likely to help at all with latency.

(Although TBH, I find 6.5ms RTL OK for feel.)

fretmeister

It feels fine and I'm in time, just want to see if I can do better really.

Bod

What version of the Focusrite drivers and MixControl are you on?  Improvements to latency were provided with more recent updates to my 1st gen 18i8.

I'm on driver 4.65.5-658, firmware 1056

Stuckfast

Really the only factors that will make a difference are buffer size and sample rate. Assuming you're on the lowest possible buffer size but you still want to get it lower, you could try operating Reaper at 96kHz instead of 44.1. Diminishing returns will set in pretty fast though, and your recordings will take up twice as much drive space and plug-ins will consume twice as many CPU resources.

fretmeister

Bod said:

What version of the Focusrite drivers and MixControl are you on?  Improvements to latency were provided with more recent updates to my 1st gen 18i8.

I'm on driver 4.65.5-658, firmware 1056

Mix Control isn't compatible with the 1st gen 2i4

I'll have to check the drivers when I get home.

WiresDreamDisasters

First thing to look at is the audio interface. Either how it's setup, or just how capable it is.

If you go into Reaper Preferences>Audio>Device and check it out. What is your block size set to?

Changing drives wont do much for latency. CPU barely comes into it when it comes to latency. I mean, a bit. But it's a minority factor. GPU doesn't come into it, although it *can* effect audio stability in the form of too-high DPC latency.

fretmeister

WiresDreamDisasters said:

First thing to look at is the audio interface. Either how it's setup, or just how capable it is.

If you go into Reaper Preferences>Audio>Device and check it out. What is your block size set to?

Changing drives wont do much for latency. CPU barely comes into it when it comes to latency. I mean, a bit. But it's a minority factor. GPU doesn't come into it, although it *can* effect audio stability in the form of too-high DPC latency.

256 - but the tick box is empty.

WiresDreamDisasters

@fretmeister ;

Okay. Tick the box. Set the value to 64. Restart Reaper if needs be. See how you get on. If it's good latency but CPU usage goes nuts, then try 128.

fretmeister

Cool.

I'll give that a try.

Thanks

fretmeister

Stuckfast said:

Really the only factors that will make a difference are buffer size and sample rate. Assuming you're on the lowest possible buffer size but you still want to get it lower, you could try operating Reaper at 96kHz instead of 44.1. Diminishing returns will set in pretty fast though, and your recordings will take up twice as much drive space and plug-ins will consume twice as many CPU resources.

I've got block at 64 now and buffer at 88200 and I've got it down to 3.1ms

Only tried it on a draft tune though - only 5 tracks on it. 4 Helix Native and 1 EZ Drummer.

John_A

That's a pretty incredible low latency for a USB interface

fretmeister

I don't tend to have a lot going on though. 
I like to record as close to a live feel as possible.

I've just written a new one that I've specifically arranged for a 3 piece band. There's no overlapping of parts, no additional rhythm guitars behind solos etc. 2 vocal parts only.

That sort of thing.

It might stumble a bit if the track count goes up.

WiresDreamDisasters

Be aware that reported latencies in DAW's are not to be trusted. The proper way to do it is to measure the round-trip-latency by measuring the time it takes an output to loop back around to an input.

andy_k

Kenny did a good vid on setting up a project for round trip latency, it helps to get things tuned up.
I use a scarlett V1, but on a Mac, and on my pc I use Asio4all, but don't do much recording through it.
I can get it low enough on my Mac to be able to record Midi from my guitar through Midi guitar 2, which amazes me.
I'd recommend tracking to audio backing tracks only, and limit the DSP to only what is absolutely necessary in any case.
 

fretmeister

WiresDreamDisasters said:

Be aware that reported latencies in DAW's are not to be trusted. The proper way to do it is to measure the round-trip-latency by measuring the time it takes an output to loop back around to an input.

I love the way you think I know how to do that!

WiresDreamDisasters

fretmeister said:

WiresDreamDisasters said:

Be aware that reported latencies in DAW's are not to be trusted. The proper way to do it is to measure the round-trip-latency by measuring the time it takes an output to loop back around to an input.

I love the way you think I know how to do that!

Sorry. Anyway, the Scarlett USB range has a round-trip latency of around 6.7ms at a buffer size of 32 at a sample-rate of 48kHz. So 64 and 128 buffer sizes at 44.1kHz is going to be higher still.
Source: https://www.musictech.net/reviews/studio-recording-gear/focusrite-scarlett-3rd-gen/

But if it feels good, then I wouldn't worry about it.

@Goldtop and his RME recommendation is a good one. Babyface Pro interface is supposed to achieve pretty tasty latencies for a USB interface. But then, that is true of all of the RME devices.

Long and short of it is - if you aren't having problems, don't worry about it! If you are, come and ask here

andy_k

Stuckfast

I may have a vested interest here but I would ignore the latency figures given in that Music Tech review, for several reasons:

(1) Their reviewer was using a Mac not a PC.

(2) He obviously didn't install the additional utility that reduces the latency to under 4ms.

(3) In any case that was with a third-generation model. The first-generation Scarletts used a different USB controller chip. 

WiresDreamDisasters

MAG WARS!

digitalscream

For what it's worth...if anybody's having trouble getting latency down and they're using an AMD CPU, the problem is likely your RAM. I've got 64GB RAM in my machine, but half of it was just running at 2166MHz. I just upgraded it to 3000MHz RAM (like the other half), and all my latency issues have disappeared.

Basically, AMD CPUs are very much dependent on memory bandwidth for low-latency performance, and they get a massive boost from higher-bandwidth RAM.