NP300X3C and Real-time audio processing

I was struggling 2 days long to get a proper platform able to process audio in real-time (with an external ASIO audio interface and a bunch of VSTs).

I faced 2 major issues :
- The power supply
- the DPC latency

1. The power supply

To be able to unlock the full power of the CPU (disabling CPU throttling), the power supply cable has to be connected (and of course to get a good autonomy of live playing !)
The problem is the power supply is really "noisy". It induces a huge quantity of noise (through USB cable). So, i'm still looking for a double insulated power supply for the laptop. I've temporary solved the issue by using and external (and heavy) transformer.

2. The DPC latency

The DPC latency is a way to qualify the ability of a platform to handle event in realt time.
There is a tool to measure that :
DPC Latency Checker

This latency depends of the the drivers, the hardware and the software.

After a fresh and complete installation (and after disabling WIFI), a measured it and i got something around 90µs (very good) but with spikes of 2.4ms (1 per minutes) These spikes make the audio processing impossible !

After re-installing from scratch and measuring after each driver and software installation, i found :
- the intel HECI cause some trouble (is it useful ?)
- the samsung easy setting is a crappy piece of software (the major cause of the trouble) ! But without it, no FN Keys

I went to the tasks scheduler to disable all samsung task (easy setting, color improvement, smart control speed boot up, ... loading) and all is good now.

Please samsung, improve this software quickly !

 

1. Have you checked the effect of isolating the ground on the power supply2 You may be getting an earth loop. Alternatively, if running on battery, try changing the power profile to set the maximum processor state when running on battery to 100%.

2. You may not need to go as far as you did in stopping things from running. I can get rid of the regular 60 second spike by killing the Smart Setting process (which I suspect is one of the children of Easy Settings) in Task Manager. The other main cause of spikes seems to be the wireless devices as you have discovered. With WiFi / bluetooth turned off and Smart Setting killed the highest latency I have observed over several minutes is 367 micro seconds. (NP900X4C but essentially the same hardware).

John

 

Hi,

1. Yes, using a transformer isolates the laptop from the earth .... You are right, it is effectivelly a ground loop... I'm lloking for a isolated power supply with a compatible plug. Running on battery with full CPU power enabled leads to 1h20 of autonomy

2. Smart Setting is effectivelly a thing launched at the same time than all "easy seeting" stuffs.I just don't understand how big brand link samsung can provide so poor tools. Wifi/Bluetooth are stuffs that involve big latency, it is known. I can live with that .... but having to kill processes is a little bit disturbing for a high-end laptop.
PS: As far as i know, kill smart control disable the ability to switch to "silent mode"

3. I had around 350us when i had Intel HECI installed ... without it, i can go as low as 120us of latency which is a very good value.

 

1. I use one of these so that I can carry around a thinner and lighter mains cable. It also breaks any ground loop.

2. Samsung's Easy Settings brings together functionality that was previously in separate programs (or not there at all). I'm sure that at least 95% of customers are happy with the one-stop shop approach but a few of us like to have more control. I've just tested my Fn+F11 and silent mode still works although Smart Settings is disabled. I've also encountered latency issues with Dell and Lenovo notebooks so these problems are not unique to Samsung.

3. Intel are one of the offenders. A couple of years ago it was the Intel Rapid Storage Technology driver which caused nasty latency spikes.

John