discuss-gnuradio
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Discuss-gnuradio] USRP2 Sample 2.4 GHz Channel


From: Douglas Geiger
Subject: Re: [Discuss-gnuradio] USRP2 Sample 2.4 GHz Channel
Date: Thu, 17 Sep 2009 09:27:15 -0400

Depending on how long you want to sample (and how much system RAM
you've got) you can also do something like using tmpfs (i.e. a RAM
disk). I've often resorted to this when doing collections lasting a
minute or less. At 25MS/s * 32bit/S (I&address@hidden) * 60s = 5.58GB
according to my calculator - so that may or may not be a viable option
for you.
 Doug

On Thu, Sep 17, 2009 at 1:00 AM, Matt Ettus <address@hidden> wrote:
> Miklos Christine wrote:
>>
>> Yes, that is exactly what I'm looking for. However, when running
>> usrp2_rx_cfile.py with decimation = 4, I get a 'S' printing to stdout. Is
>> anyone else able to run usrp2_rx_cfile.py and not get that overrun message?
>> What could be the reason for 'S'? Is it a limitation on how fast we can
>> write the samples to the hard disk?
>> I want to keep the maximum number of samples possible.
>
>
> At a decimation rate of 4 you are generating 25 MS/s.  If those samples are
> complex shorts, that works out to 100 MB/s.  If those samples are complex
> floats, that is 200 MB/s.  In the former case, you really need a RAID array
> of at least two fast drives to keep up.  In the latter, you're going to need
> to do something more exotic.
>
> Matt
>



-- 
Doug Geiger
address@hidden




reply via email to

[Prev in Thread] Current Thread [Next in Thread]