1 Topic by enes.sabanovic (edited by enes.sabanovic 2020-04-26 23:29:13)

  • Registered: 2020-04-25
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Topic: Buffer settings go up with higher sample rates with HDSP9632

Hello.

I'm trying to get ultra low latencies with the HDSP9632 and an electronic drum kit triggering VST's. The drum module needs about 3ms to send a midi signal and with the added latency from the sound card (and maybe an extra ms for the MIDI signal) we are up to maybe 6ms which is acceptable but I wonder if it can be improved further.

The lowest latency seems to be 2.5ms output (input is MIDI so no I assume no input latency).

I tried to go to 96kHz but the buffer goes up automatically to 64 samples.

Is there any way to keep it at 32 samples even at higher sample rates or maybe set it to a lower buffer size?

2 Reply by ramses (edited by ramses 2020-04-26 23:28:47)

  • ramses
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Re: Buffer settings go up with higher sample rates with HDSP9632

With higher sample rates you need bigger buffer sizes otherwise you would get audio loss.
A request for 32 samples ASIO buffer size at double speed (88.2/96 kHz) would be equal to a request for 16 samples at 44.1/48 ...
Look at the RTL .. with higher sample rates the RTL becomes lower .. so relax.
But you get higher stress on the PC ... as it needs to process the double amount of data per time interval.

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14
  • Registered: 2020-04-25
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Re: Buffer settings go up with higher sample rates with HDSP9632

ramses wrote:

With higher sample rates you need bigger buffer sizes otherwise you would get audio loss.
A request for 32 samples ASIO buffer size at double speed (88.2/96 kHz) would be equal to a request for 16 samples at 44.1/48 ...
Look at the RTL .. with higher sample rates the RTL becomes lower .. so relax.
But you get higher stress on the PC ... as it needs to process the double amount of data per time interval.

Yes I know but seeing how this card seems unaffected regardless of what you throw at it I was wondering if there was a way to set it lower. It seems I can run huge projects at the lowest available latency and I'm wondering if it was possible to maybe use less buffers with smaller projects. On some of my older cards by other manufacturers I had the option to go lower (even if it meant crackling).

192kHz seems to have a bit less latency at 1.9ms though.

  • ramses
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Re: Buffer settings go up with higher sample rates with HDSP9632

I would trust the exerience of RME what buffer sizes to offer.
It has to run on other customers PCs as well, not only on yours.
Otherwise support cases come in, why it does not work...etc...

Months ago I read a review. At the same ASIO buffer size the RME driver had nearly half of the RTL time of the competitor.
So .. the final RTL does not only depend on the ASIO buffer size but also
- on driver efficiency and
- I think also, how much internal safety buffer a company implements

See the RTL of different RME solutions, its all fine:
https://www.tonstudio-forum.de/index.php/Attachment/2343-UFX-UFX-RayDAT-Latencies-v2-jpg/

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14

5 Reply by enes.sabanovic (edited by enes.sabanovic 2020-04-27 13:47:10)

  • Registered: 2020-04-25
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Re: Buffer settings go up with higher sample rates with HDSP9632

ramses wrote:

I would trust the exerience of RME what buffer sizes to offer.
It has to run on other customers PCs as well, not only on yours.
Otherwise support cases come in, why it does not work...etc...

Months ago I read a review. At the same ASIO buffer size the RME driver had nearly half of the RTL time of the competitor.
So .. the final RTL does not only depend on the ASIO buffer size but also
- on driver efficiency and
- I think also, how much internal safety buffer a company implements

See the RTL of different RME solutions, its all fine:
https://www.tonstudio-forum.de/index.php/Attachment/2343-UFX-UFX-RayDAT-Latencies-v2-jpg/

Yes RME is one of few companies that report the accurate latency. There are benchmark threads where you can see actual latency measurements on different interfaces. RME is on top on all benchmarks.

I know all this but it would have been nice to have the option to set maybe 16 samples in certain situations. All projects don’t have to be 30+ channels.

That madi fx would be optimal for my application with that low output latency. Over my budget undortunately.

  • ramses
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Re: Buffer settings go up with higher sample rates with HDSP9632

As you might need AD/DA the UFX+ would not be bad, as it has AD/DA already included and by this lowest values.
For the MADI FX you need to add the times for converter latency for the AD/DA converter behind MADI/AES.
2,6 vs 3+ms

But tbh when playing a virtual amp playing starts to become uncomfortably with 256 samples buffersize.
Still manageable, but 128 feels better. 512 gives rapid slowdown on playing.
So with 32, 64 and even 128 (staying under 10ms) you should be fine.

Why do you have such high requirements .. simply some fancy ideas "I want lowest latency on planet" or is there any technical reason behind it ?

BR Ramses - UFX III, 12Mic, XTC, ADI-2 Pro FS R BE, RayDAT, X10SRi-F, E5-1680v4, Win10Pro22H2, Cub14
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Re: Buffer settings go up with higher sample rates with HDSP9632

ramses wrote:

Why do you have such high requirements .. simply some fancy ideas "I want lowest latency on planet" or is there any technical reason behind it ?

I play guitar as well and standing 10 feet from an amp is fine with 10ms latency. It's a whole different story with drums.

First of all, electronic drums modules need time to trigger a signal accurately, about 2-3ms. The there is about 1ms of latency added before the MIDI signal reaches the computer. Then you have the output latency on top of that. Best case scenario is about 5.5-6.5ms with the HDSP. This is fine. However less would have been nice.

A drum module will play sounds in about 3 ms after you hit a pad. This feels very snappy. The same latency as when playiing an acoustic kit.