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<== Date ==> <== Thread ==>

Subject: Re: areaDetector video (Was: network video)
From: "J. Lewis Muir" <[email protected]>
To: EPICS Tech-Talk <[email protected]>
Date: Wed, 01 Sep 2010 09:33:27 -0500
On 9/1/10 7:14 AM, [email protected] wrote:
> As a guide, on an Intel X5260 processor (Dell 2950) with 3 1024x768 Mono
> cameras @ 30fps uses 30% of 1 core for acquisition and another 35-40%
> for compression. The compressed stream is about 10% of the uncompressed
> stream. However, despite the data from the three cameras only being
> 70Mbytes/sec, only one core being utilised so another core is idle, and
> it being a fully switched network, if you add another camera then frames
> start being dropped. So, as they say, your mileage may vary.

Hi, Nick.

If only one core is being utilized, perhaps the software isn't written
to take advantage of the other core.  In this case, the behavior you
observed doesn't seem so surprising: 30% + 40% = 70%. 70% / 3 = 23% per
camera.  One might then anticipate that adding another camera would run
the CPU usage up to 70% + 23% = 93% which might be high enough to cause
frames to get dropped.

Is there a way to run more than one instance of your software?  When
software isn't written to take advantage of more than one core, you can
sometimes overcome this if you can run more than one instance of the
software; the operating system will take care of scheduling the second,
third, etc. software process on other cores.

Lewis

Replies:
RE: areaDetector video (Was: network video) nick.rees
References:
network video John Dobbins
Re: network video emmanuel_mayssat
RE: network video Mark Rivers
areaDetector video (Was: network video) emmanuel_mayssat
RE: areaDetector video (Was: network video) Mark Rivers
RE: areaDetector video (Was: network video) nick.rees

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