Choppy/Stuttering audio across platforms.

[dsalomon]

I'm afraid that I don't have any experience with USB based devices. You'd be adding a hub to an already existing USB port which,on a laptop is certain to give you worse performance than using the USB port directly.

Many laptops have really abysmal USB performance, which leaves you without much of a solution unless the laptop has some higher bandwidth capable expansion port, such as a PC Card expansion port, for which you should be able to find USB cards.

Best - David, AG4F

[13dka]

@all:

Please note that you all have the same symptom, which can be caused by a variety of quite different issues, hence troubleshooting this is done best in a separate thread for everyone having this problem, or in other words, people chiming in with "I have the same issue" is usually making troubleshooting pretty hard and you might not get the help you were hoping for.

Audio breaking up can be caused for example by

- USB bottleneck issues as indicated by Tech_Support

No idea how to check this this right now. Maybe when you checked all of the stuff below without any findings, that's what's left and the most likely culprit.

- a variety of CPU related issues, like a simple "not enough CPU power", thermal throttling (cooling problems), power saving issues (core parking, EIST etc. settings in the BIOS causing CPU clock reduction).

Check/clean your fans, use CPU-Z or a similar tool to check if core clock and multiplier remain constant, if not try to turn off EIST/C1E and whatnot in the BIOS. This is often not possible on laptop BIOSses. The only way then and also related to that:

- Windows power scheme is not on "high performance"

Change that.

- A rogue process or service kicks in and steals CPU power from radio processing

Can be checked quite easy by monitoring the running processes and their CPU load in Task Manager. Also check the Performance tab is something is pegging one core.

- A driver causing high DPC latencies, stopping processing of anything else

Run the DPC latency checker http://www.thesycon.de/deu/latency_check.shtml while running your SDR software and if it indicates (very high red spikes) possible interruptions coinciding with dropouts/stuttering you can use LatencyMon http://www.resplendence.com/latencymon to find the offending device/driver. In particular on laptops it's often the WLAN adapter causing dropouts, so turning that (and your card reader, webcam...) off (ideally in Device Manager) should be the first thing you try.

[tatamare]

On old dell latitude d630 core2duo 2g ram,os win10, run simultaneously; hdsdr (as panadapter), cw skimer,N1MM+, plus another utility (virtual audio cable and virtual com),and don't have any problem at all. Tips, good quality USB cable, antivirus disabled, and Windows non esențial services disable, for Windows service's try caled "game Booster" utility.
GL, 73

[slehy]

I had the same problem, but with SDR console. HDSDR and SDRsharp were fine. PC Win XP, RAM 4gB, processor Intel core 2 duo 2,53Ghz.
It was enough to change the "Audio" at SDRconsole.

[slehy]

I had a similar problem. PC Win XP, RAM 4gB, intel Core2duo 2,53gHz.
The problem was only SDRconsole. HDSDR and SDRsharp been without problems.
It was enough to change the "Audio" menu SDRconsole.
I am sorry for my English. Google translation

[NN4F]

Also you say you are using v2.3 build 2355, simon has done some major updates to 2.3 for the sdrplay, now at build 2381, try the latest version, works fine here on a i3 laptop @ 2.1ghz with 6gb ram...

Paul - NN4F

[rskunath]

[quote="dsalomon"]Here's the specific model I got: http://www.amazon.com/gp/product/B00HJZ ... detailpage.

David, I take it that this card slows to USB2 and still works well with the rsp device.

I'm having the stuttering on a very high end PC and don't mind the extra cost for the card, but I wanted to make sure that this would work with the rsp2.

[rskunath]

Just as a follow-up, I did actually finally install this StarTech card - http://www.amazon.com/gp/product/B00HJZ ... detailpage. It's very nicely done and has a separate power feed from the PC power supply to feed the USB ports. I also picked up a nice little USB3 shielded cable that has a convenient desktop stand.

The bad news is that I still have the choppy audio every time I set the RSP2 to a bandwidth higher than 5 MHz. The CPU usage (AMD FX-8350 8-core at 4.1 GHZ, 32 GB RAM) is low and the waterfalls are smooth. I don't have ASIO drivers for the ASUS onboard Realtek HD audio I'm using. So I don't know if that would be anything to look at. I don't see any ASIO drivers on the ASUS site for the Sabertooth FX990 R2 MB I have. Latency reads low when I test it, so I don't think that's the problem.

I'd still like to get this ironed out and I'm looking for ideas about what to try next.

That USB board was a good investment just for the high-quality rear ports I now have available.

Thanks in advance for any ideas to try...

[sdrplay]

Check the CPU load on each core. I suspect you have 1 core that is maxing out. It's a known issue on our list of things to look at.

Best regards,

SDRplay Support

[rskunath]

I've checked that and nothing over about 60% max, most are under 30%, some lower.