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

Subject: EPICS channel access performance test
From: tanushyam bhattacharjee <gettanu@yahoo.co.in>
To: tech-talk@aps.anl.gov
Date: Tue, 10 Jul 2012 00:10:49 +0800 (SGT)
We want to measure channel access performance say for an integer data type using "catime" tool and as per our expectation we have got the result in a linux-x86 platform which concludes something like this:

(i) The plot "No. of PV" vs "Average Time" is like a bath tub curve.
(ii) The initial slope explains the network overhead is more than the size of PV
(iii) The middle plateau explains the optimised performance of CA as the number of PVs are high.
(iv) The final slope explains that CPU is overloaded with no of PVs and from here we can draw the threshold optimised performance of CA for an ioc.


However, when we are performing the same for ARM9 and FPGA-microblaze the final slope is not coming with the data generated though the ioc CPU is overloaded and it maintains the plateau for ever.

Can anybody explain the reason?


Tanushyam Bhattacharjee, Shantanoo Sahoo

Variable Energy Cyclotron Centre
Kolkata,India

Replies:
RE: EPICS channel access performance test Hill, Jeff

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