Re: [Discuss-gnuradio] File sink causes "S" errors

[Josh Blum]

Can you benchmark your hard disk for sustained rate?

I don't think that most disks, even SSD,s can sustain a write rate of 
25Msps @ 4 bytes a sample (if you are capturing shorts) = 100MB/s

-Josh

On 10/05/2010 06:35 PM, Thomas Hobiger wrote:
> Hi everybody,
>
> I am running a USRP2 with a DBSRX and talking to the hardware via raw
> ethernet. Running GRC goes well (e.g. doing a real-time FFT spectrum),
> but when I start recording on disc I get many "S" messages ("2
> successive packets which do not have 2 successive sequence numbers")
> after about 10 seconds. I am currently sampling with a decimation of 4,
> but the problem remains with other decimation factors as wekk, just the
> messages show up slightly delayed. I think the HD itself is not the
> reason as I am recording to a 80 GB SSD, which has EXT4 and is mounted
> in a quite fast mode (I have benchmarked the I/O giving me much more
> bandwidth than what streams in from the USRP2).
> I have started to modify parts of the GNURADIO code, but changing buffer
> sizes does not help much.
>
> Is there anybody who experienced similar troubles?
>
> Regards,
> Thomas Hobiger