Predicting system latency

[ben howes]

Hi,
I've spent some time trying to get low enough latency for playing virtual instruments from my PC. I've carefully been through the booklet from cantible software and various other online resources but haven't yet achieved acceptable results. It's an AMD system on chip business PC so I'm possibly hamstrung by the hardware. Considering whether I should give up on it and start again with different hardware, or even OS.

My question is this: can one know if a system will be suitable for live playing of vst instruments based on the pc specification?
Is it possible that a low latency distro of Linux could out perform Windows in respect of latency?

My system :
Lenovo s75 SFF
AMD Ryzen 5 3xxxG series with integrated graphics
16gb ram
512 M2 drive
Windows 11
NI complete audio 6 v2

I've gone as far as forcing uninstall of the Vega graphics. I've been using latencymon to measure effects of my interventions.
Thanks
Ben

[Wonks]

Latency really comes down to
a) Drivers
b) Background tasks taking up processor time
c) Processor capability and the amount of software you can run

Assuming the drivers are decent, the primary issue are the background tasks as shown by LatencyMon.

Get those sorted if you can, and then you should be limited by processor/system capability and how processor hungry your VST/VSTis are. When pushing it, more RAM always helps, but can only do so much.

So what results are you getting with LatencyMon?

[ben howes]

It's been a while since I tried TBH but from memory it was either direct x or some windows core driver wfm000 or the like.
I don't want to waste your time helping with trouble shooting as I only want to have some fun with scuffham really.
The interesting thing was that I thought this fairly modern machine would have good latency but I was wrong!

[Wonks]

It could be down to a simple system setting.

I posted in here a few weeks ago now about how my new i7 PC had latency issues caused by ‘core parking’ being turned on. Once turned off, I could get a sub-1ms round trip latency with my interface (though under 2ms is more common for me once projects get bigger).

[Wonks]

In addition, I have noticed that the DAW choice can affect minimum buffer settings e.g. I find Cubase needs a bigger buffer than Studio One does.

[ajay_m]

The KA6MK2 has pretty good drivers and ought to be able to manage latency figures around 5ms or so at 44.1KHz and rather less at 96KHz.

Now that said, there are some things to consider. Firstly of course you do want to run latencymon and just check nothing's causing intermittent spikes. Otherwise the exact DPC latency figure isn't terribly important as long as latencymon is happy.

If you *do* have issues here then WiFi is the first place to look (try disabling it) and then the graphics driver, especially when smooth scrolling, where some driver writers have taken a few liberties with how much time they block interrupts.

Assuming you don't have issues then the next thing to be aware of is that some virtual instruments, particularly Kontakt-hosted, are sensitive to the engine settings, particularly the pre-fetch buffer size. This can often be wound down to only around 6K or so, particularly on SSD-based hardware, and can reduce crackle significantly. It's something to experiment with for sure.

After that some scripted Kontakt instruments in particular can be very demanding on lower-end CPUs. A good example would be Embertone's Walker Piano and to be honest most of their products. On a four core i7 machine you can struggle to get these to play at low latency without the odd crackle. Note though that limiting the maximum voice count in Kontakt can help here, as particularly with the piano you can rack up a LOT of voices playing fast runs even with judicious use of the sustain pedal.

I will say that now I have upgraded to an 8 core Ryzen 5800 laptop then even the most demanding VSTs seem to work well at low latency - I'm now running everything at 96KHz using a Yamaha DM3 mixer as the audio interface and Reaper reports a couple of milliseconds latency.

[Wonks]

In this case I think Ben is just using Scuffham amp sim software.

https://www.scuffhamamps.com/

So no sample files, just processor loading.

[ben howes]

Thanks for the advice. I've been using grand orgue (sample based pipe organ) as well as BFD and a trial of scuffham. Only one stand alone instrument per session, no DAW.
I've definitely tried core parking, uninstalling the Vega graphic driver, on board sound, adjusting buffer and sample rate and various other tweaks. There is no WiFi card installed but I disabled the ethernet card for good measure.
I tried installing Ubuntu Studio and in grand orgue that seemed to eliminate the pops and clicks . I wonder if Windows is the elephant in the room!

[Wonks]

‘Windows on your machine’ is probably a better description.

Let LatencyMon run for a while and take some screen shots of the results. If you can get that reporting in the green, you should then be OK.

[ef37a]

Hi Ben, I used a KA6 with an AMD 6CORE 3G Black and got very acceptable latency with Win 7. This i7 W10 Lenovo laptop was also fine with the NI interface but it is now used with a MOTU M4, probably even better ASIO drivers?

I doubt "Windows" is your problem unless of course it is doing something you are not aware of! Long shot but a question to Native Instruments might give some clues?

Dave.

[Wonks]

It's not just NI, it's all his VSTis.

[ef37a]

It's not just NI, it's all his VSTis.

Get away!

Dave.

[ben howes]

https://drive.google.com/file/d/1C-HBY7 ... sp=sharing
https://drive.google.com/file/d/1MC3SIR ... sp=sharing
Here are my latencymon outputs, Parkcontrol on performance setting.
Strangely the day after I opened this thread, I was getting [dark] green from latencymon and had some fun with scuffham.
Today, not so much...
I've got the latest windows and drivers. Up to date graphics driver, with all the fancy options disabled. No wifi card.
Should I invest more time in this or begin again with a better machine?
Thanks
Ben

[sonics]

Have you tried disabling the network card or networking?

Some computers will never be great for audio due to various hardware configuration and driver issues, unfortunately.

[Lostgallifreyan]

Have you tried disabling the network card or networking?

Some computers will never be great for audio due to various hardware configuration and driver issues, unfortunately.

It often has to do with how well the software allocates buffer memory, but only the coder can control that.. The Windows API has enough methods to keep a coder interested for some time!

A nice trick for a standalone system on W98 was to set the audio program as the 'shell' in System.ini, which is very easy and helps a lot because of the vast reduction in internal windows messages. I imagine the trick can be applied to later Windows but I don't have one to test here.

Even with that shell method I found that glitching, while a lot more rare, did happen if I pushed for audio buffer latency below 10 ms using the MME WaveOut API (and Echo Layla 20 bit interface), but disabling systems in the BIOS might help, by preventing unwanted hardware interrupts. I'm not sure that doing it in the device manager would be enough..

I suspect that if this shell method seemed to be needed in WXP or later, then there may be something significantly wrong with driver or hardware that this method might not do enough to be worth it.

I never try to predict latency. I don't bet either, but it might be a better effort because predicting a race based on a horse's form might be easier.

[ajay_m]

I don't like your ndis.sys result. Can you sort results by descending highest time? Is this the worst figure still?
Definitely disable networking and retest I think, before we move forward.

[ef37a]

Have you tried disabling the network card or networking?

Some computers will never be great for audio due to various hardware configuration and driver issues, unfortunately.

Most of this is way above my pay grade but I have been an 'observer' for over ten years and back then it was mostly PCI interface cards if you wanted the lowest latency. External AIs were Firewire but that was far from a simple option. If the PC or laptop* did not sport a TI 1394 controller (or one specified by the AI mnfctr) you were pretty much up the sewage creek sans means of propulsion.

*These were largely despised for 'serious' audio work despite forum questions every day about a suitable one. We could all see the attraction but in truth there were few laptops about then that could cut it. USB interfaces, except from a very few people like RME, were very long in gestation before they had low enough latency (or even decent mic pres!)

So I am not surprised that once in a while folks find a bad 'un.

Best of luck chap.

Dave.

[sonics]

One other thing. Connect devices to different ports. Laptops will often have a different chipset running the USB2/3 ports. You can get errors and slow data transfer sometimes; try swapping your interface about if possible and retest, also anything else connected to USB ports (but preferably you have nothing).

[ben howes]

To be honest this machine was an eBay punt and it is entirely suitable for general computing. It cost very little so if I end up going out to buy a music dedicated computer I've lost very little.
Thanks all for chipping in

[ef37a]

To be honest this machine was an eBay punt and it is entirely suitable for general computing. It cost very little so if I end up going out to buy a music dedicated computer I've lost very little.
Thanks all for chipping in

If you are in a "nothing to lose" situation it might be an idea to format the drive and re-install Windows 11 (even 10?!)

Dave.

[Wonks]

It's worth using the SFC and DSIM commands to check for system file errors and fix them.

https://youtu.be/acxCueZ2dVQ?si=mErRs-qHVRKZE0B4

It probably won't cure the latency issue, but at least the rest of the system will be in better shape. However, it may improve things.

[robin0112357]

To save future readers from watching YouTube...

Right-click the Start button.

Choose "Command Prompt (Admin)" or "Terminal (Admin)".

Type "sfc /scannow" to fix corrupted Windows System Files.

If OK, you wil get message "Windows Resource Protection did not find any integrity violations."

If not, reboot in Safe Mode and try again.

If still no dice, run the Deployment Image Servicing and Management (DISM)
tool.

In the same prompt, type "DISM /Online /Cleanup-Image /RestoreHealth".