Graphics Formats speed decreased for reason unknown.

[RautSa]

Greetings,

I have kind of obscure problem to solve: execution time of one LabVIEW program has drastically increased (10-20 times) for some reason. The problem occurred at least half a year ago, and no one really remembers what changed at that time. It’s the same problem on multiple identical computers. While asking users about their experiences I have narrowed the problem down to one sub-VI (see attachment). It creates an array out of PNG-files, and draws pixmaps.

When I run the program directly in LabVIEW on my own computer there’s no problem (showing the exact same pictures as the user in about 1/10 of the time), though the sub-VI takes clearly most of the executions time. User runs the program via TestStand operator interface, using TestStand Runtime 2014 and LabVIEW  Runtime 2014, on Windows 7. I use Windows 7 and LabVIEW 2014.

I know that the computers have stayed the same this whole time, so this shouldn’t be a hardware problem. I also know that PNG-files are in the users C:\temp, they are not retrieved from remote hard drive. What I don’t know is which softwares have changed. Maybe someone else has had similar phenomenon?

-RautSa

[rajamodol]

Hi,

perhaps this could increase your speed performance. I didn't try it yet, just give you a quick idea.  Right-clicked on loop, select "Configure Iteration Parallellism.."
Regards,
Rajamodol 

[Ben]

Do you, by any chance have to work in an evironment where an IT department is forcing software updates and virus check updates?

When you indicated that nothing has changed (and assuming your disk drive has not suddenly been filled or is starting to fail requiring retries to ge tht data) it sounds very similar to situation I have seen where the software version of BIg Brother is trying to protect us from ourselves...

Ben

[altenbach]

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@rajamodol wrote:

perhaps this could increase your speed performance. I didn't try it yet, just give you a quick idea.  Right-clicked on loop, select "Configure Iteration Parallellism.."

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The slow part is probably disk IO, which is sequential, so I won't expect any parallelization advantage. It migh actually slow things down due to the parallelization overhead.

I am with Ben that this could be due to some over-eager security software suite. It could also be a hardware difference.

If your dev computer has an SSD and othe others have a plain old HD, there will be quite a difference.

Are there other hardware differences such as the amount of RAM and the CPU type?

What else is running on these other computers? What is their performance index? What is their average IO and CPU load seen in the task manager? Are they in a clean state or e.g. waiting for a reboot after update? Have you tried rebooting? Anything interesting in the even viewer? Anything broken in the device manager?

What are the power saving settings? If it is agressive, the HD will go to sleep often and needs to spin up first.

Please incorporate a reliable benchmark into your software that e.g. display the total image load time in seconds in a small indicators so you don't need to guess.

[RautSa]

@rajamodol Thanks for the tip, that actually cut off about 30 percent of the sub-VI's execution time. Nice feature, it's good to know about it.

@Ben Yeah, that's exactly the environment where I work. Has there been any software changes around the time the problem first occurred? Most likely. I'll try to find if there is some kind of log of software updates.

@altenbach There are some differences in hardware bethween my computer and the users computer: I have Intel i7 (8 GB RAM, 2.9 GHz), the user has Intel i5 (8 GB RAM, 3.2 GHz), both have HD. But the program has worked much faster on the users computer in the past.

-I have tried rebooting

-Nothing broken in the Device manager

-All of the computers power saving setting have been set to "Never"

-I hope to get answers to your other questions soon.Though I might not get a chance before the last year in university starts (in which case I believe the problem still awaits me in January when I start my thesis).

Thank you all for your answers.

-RautSa

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