What's Min PC Spec for RTL2832+HDSDR

[Codeine]

AMD 1.6Ghz
Win XP Pro 1.5Gig Ram
Peak Model 102569AGPK DVB-T Digital USB
RTL2832  and FC0012 Tuner


What is the minimum spec PC I can run RTL2832 USB and HDSDR...? I have it all installed and working correctly (well almost) in a 1.6Ghz machine but the program audio stutters constantly.Tried it on a 2.2Ghz machine and the audio stutter wasn't much better but had slowed to ounce a second and could hear the local broadcast station.I guess this thing is just so processor hungry that it can't work properly but don't want to upgrade my PC to a quad core just use this new SDR.Will have to find a distro and give GNU Radio a try but realy wanted it to work in windows and just what is the lowest spec PC that everybody is using.

Paul
 

[Adam Nielsen]

> What is the minimum spec PC I can run RTL2832 USB and HDSDR...? I have

> it all installed and working correctly (/well almost/) in a 1.6Ghz

> machine but the program audio stutters constantly.

If you're using HDSDR it will show the CPU usage at the bottom - as long
as that's under say 90% the CPU shouldn't be a problem. I would think
1.6GHz would be fine, especially at lower sample rates.

Make sure you're using a USB2.0 port. If you have connected the RTL2832
to a USB1.1 port then it won't be able to deliver the data fast enough
and you will get that type of stuttering. If in doubt, try one of the
ports on the back of your PC as they are most likely to be USB2.0.

> don't want
> to upgrade my PC to a quad core just use this new SDR.

I believe HDSDR is single threaded so a quad core will just give you
three idle cores :-)

Cheers,
Adam.

[Miguel A. Vallejo]

Adam Nielsen wrote:

>>> >>> What is the minimum spec PC I can run
>>> >>> RTL2832 USB and HDSDR...? I have it all
>>> >>> installed and working correctly (/well
>>> >>> almost/) in a 1.6Ghz machine but the
>>> >>> program audio stutters constantly.

>>> If you're using HDSDR it will show the CPU usage
>>> at the bottom - as long as that's under say 90%
>>> the CPU shouldn't be a problem.  I would think
>>> 1.6GHz would be fine, especially at lower sample
>>> rates.

If you are on Windows machine no matters what CPU you have. If you are using a simple Atom or a quad core cpu with 5% cpu load you will have audio stutters. More or less constantly depending on your readlen settings, but you will never get smooth audio. I suspect from libusb0 / Winusb library. It would be nice to have a native implementation on Windows but...

I tested different buffer sizes / packet length combinations. Some worked better than others. Maybe there is a magic combination of buffer size / packed size / FFT size that works fine but I have not found it yet.

With Linux seems to work much better.

[Balint Seeber]

Adam's tip for watching the CPU usage meter is good one, but I believe you need to divide 100% by the total number of cores in your machine to calculate the CPU usage limit for HDSDR (e.g. on a quad-core machine, you don't want HDSDR usage to exceed 25%).

I have been testing with HDSDR on a quad-core 2.4 GHz machine, and Linux on a dual-core 2.5 GHz. I am able to achieve 'smooth' audio with both. Depending on the app/OS (e.g. NBFM vs. OP25) I might adjust the 'readlen' parameter, but the default generally seems to work well for me.

There is still some optimisation to be done, however testing with different values of 'readlen' can often be used to manage CPU usage issues. Formula:

512 * (2 ^ N) where N >= 0

libusb0 is not used for RTL on Windows (libusb0 installs its own kernel driver, and is only used by ExtIO_USRP in Legacy USRP mode, i.e. pre-UHD). libusb1 actually uses the native WinUSB implementation that is part of Windows since Vista (also available for XP), and so does not require additional kernel drivers - just the userland implementation of the libusb1 API.

[imo]

I am running hdsdr on a Celeron M530 1.7ghz notebook (2gb ram). The 1.024Msps is the max setting where the decoding works smooth on it.

Wr+ interrupts itself while decoding every few seconds for a while (0.5sec?) in any setting. Wr+ does not work smooth on my 2.2ghz amd dual core too (??).

imo

[Codeine]

Hi everyone

Thanks for all the info and advice and think my motherboard has USB 2 but the all four usb ports on the rear appear to be USB 1.1.
Is there a simple test or  some software so I can identify which of the four usb ports are actually usb 2...? I definitely have
a via usb enhanced controller listed in device mangler but need to find out if the four usb sockets on the rear are indeed usb 1.1 or 2.

My initial tests indicate that they are all usb 1.1 and the usb 2 option requires me to fit for usb sockets onto a to a header on the motherboard.
Or would it be easier to retro fit a usb 2  PCI card if such a thing exists.I could dig out an old Pentium 2Gig machine which I am certain has usb 2
and have three PC's in shack. I think I have a KVM switch somewhere in my mid 90's computer hardware collection....whatever happened to computer fairs..!

Cheers Paul

[Adam Nielsen]

> Is there a simple test or some software so I can identify which of the
> four usb ports are actually usb 2...? I definitely have

> a _/via usb enhanced controller/_ listed in device mangler but need to

> find out if the four usb sockets on the rear are indeed usb 1.1 or 2.

I'm not aware of any, but if you view devices by connection (in Device
Manager), you can view the properties of the root hub under the USB
controller the rtl-sdr is connected to. At least under Win 7 there is
an Advanced tab in the properties window which will tell you whether the
hub is running at high-speed (USB2) or full-speed (USB1.1)

Hopefully from there you can work out which ports are definitely USB2.

> Or would it be easier to retro fit a usb 2 PCI card if such a thing
> exists.

You can certainly get these very cheaply on eBay. They're probably even
cheaper now that USB3 is out.

Cheers,
Adam.