PDF text not being cached?  SOLVED

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David.P
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PDF text not being cached?

Post by David.P »

Hello Forum and Tracker Support Team,

I am currently working with PDF-XChange Editor on a laptop that has less power and less memory than my desktop PC.

The desktop PC has 32 GB RAM, while the laptop has 24 GB.

The performance settings of PDF-XChange Editor are set as follows:

Image
(Laptop)

Image
(Desktop PC)

Actually, all PDF-XChange Editor settings on the laptop and on the desktop PC are identical since the settings file was exported from the desktop PC and imported on the laptop.

When searching through a large PDF file of several thousand pages, I notice that on the laptop, the text does not seem to be kept in the RAM cache as usual.

This is indicated by the fact that each new search for text in the file on the laptop takes half a minute (exactly the same as the first search after having opened the file), whereas I am used to only the first search taking somewhat longer, and each subsequent search being performed in RAM virtually instantaneously.

PDF-XChange Editor also occupies only about 600 MB of RAM on the laptop when the PDF file in question is open, while it occupies over 2 GB RAM on the desktop PC with the same file open.

What could be the reason that the text does not seem to be cached on the laptop, and how could I fix this?

Best regards
David
Last edited by David.P on Tue Jul 12, 2022 3:48 pm, edited 4 times in total.
David.P
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TrackerSupp-Daniel
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Re: PDF text not being cached?

Post by TrackerSupp-Daniel »

Hello, David.P

Thank you for the report, Windows has more control over this than the performance tab would indicate. This tab simply defines how much memory the Editor will request access to, if windows sees that other apps need or are actively using the memory more than we are (which is quite common on Windows 10+ devices with less than 16gb), Windows may be swapping our data to the disk. If you are using a high speed SSD, that may not result in a large difference in data speeds, but if the device has an HDD, you could see a noticeable difference after this happens.

I have spoken with the Dev team and they have requested screenshots of your task manager "performance" tab (particularly with a focus on the memory category), at 3 points in time:
1. When the Editor and a document have recently been opened, before any search begins.
2. Immediately after a search has been performed.
3. After a long enough wait that the software would give you the slow secondary search, immediately following the second search.

Kind regards,
Dan McIntyre - Support Technician
Tracker Software Products (Canada) LTD

+++++++++++++++++++++++++++++++++++
Our Web site domain and email address has changed as of 26/10/2023.
https://www.pdf-xchange.com
Support@pdf-xchange.com
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David.P
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Re: PDF text not being cached?

Post by David.P »

Thank you Daniel,

I will check the memory consumption curve and provide screenshots as soon as I am back at that laptop!

Best regards
David
David.P
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PDF text not being cached?

Post by Tracker Supp-Stefan »

:)
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David.P
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Re: PDF text not being cached?

Post by David.P »

Hello Forum and Tracker Support Team,

I have now recorded the memory usage pattern on the laptop in question, and for comparison on a desktop PC, using the same PDF file. The exact specifications of the two systems can be taken from the linked pages at Userbenchmark.com (the benchmarks were run today). PDF-XChange Editor settings were identical on both systems in each case.

Memory usage curve Laptop ThinkPad T480 24GB RAM:
Laptop specs and benchmarks: https://www.userbenchmark.com/UserRun/53824699
Image
Peak memory usage: 1.3 GB

1: Opened file with ca. 380 MB and ca. 7000 pages.
2: First text search: ca. 33 seconds
3: Subsequent text searches for the same search term: ca. 33 seconds
4: Closed file; reset PDF-XChange Editor settings to default; opened same file again
5: First text search: ca. 33 seconds
6: Subsequent text searches for the same search term: ca. 33 seconds
7: Closed file


Memory usage curve Desktop PC 32GB RAM:
PC specs and benchmarks: https://www.userbenchmark.com/UserRun/53824517
Image
Peak memory usage: 2.2 GB

1: Opened file with ca. 380 MB and ca. 7000 pages.
2: First text search: ca. 28 seconds
3: Subsequent text searches for the same search term: ca. 1 second
4: Closed file; reset PDF-XChange Editor settings to default; opened same file again
5: First text search: ca. 28 seconds
6: Subsequent text searches for the same search term: ca. 1 second
7: Closed file


It can be seen that on the laptop, each subsequent search takes the same amount of time as the first search, about 33 seconds, while subsequent searches on the desktop PC only take about 1 second each.

It is also evident that on the laptop, the already much lower memory usage drops even further to around 700 MB immediately after the first search, and remains at that relatively low level. In contrast, memory usage on the PC remains constantly at about 2.2 GB after each first search run.

It would be great if we could find out why the text on the laptop doesn't seem to be kept in RAM cache, and how to fix this issue on the laptop.

Thank you
David

--
PS: oddly enough, the same search with Adobe Reader on the laptop takes between 6 and 9 minutes each time 🤦🏼‍♂️🤦🏼, while the same search with Adobe Reader on the desktop PC currently takes over 4h (extrapolated, stopped search after about half an hour with only about 600 pages searched)
Last edited by David.P on Tue Jul 12, 2022 4:53 pm, edited 1 time in total.
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Re: PDF text not being cached?

Post by TrackerSupp-Daniel »

Hello, David.P

Thank you for this, I have passed this information along to the Dev team for investigation. I will keep you posted when they let me know what was found.

Kind regards,
Dan McIntyre - Support Technician
Tracker Software Products (Canada) LTD

+++++++++++++++++++++++++++++++++++
Our Web site domain and email address has changed as of 26/10/2023.
https://www.pdf-xchange.com
Support@pdf-xchange.com
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David.P
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Re: PDF text not being cached?

Post by David.P »

Awesome Daniel, thank you.
Best Regards,
David
:)
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PDF text not being cached?

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:)
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TrackerSupp-Daniel
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Re: PDF text not being cached?

Post by TrackerSupp-Daniel »

Hello, David.P

Is this laptop by any chance a 32-bit system? If so, that would explain the reduced cache size, as only ~1GB of RAM can be used to cache content in the PDF-text/context.

Kind regards,
Dan McIntyre - Support Technician
Tracker Software Products (Canada) LTD

+++++++++++++++++++++++++++++++++++
Our Web site domain and email address has changed as of 26/10/2023.
https://www.pdf-xchange.com
Support@pdf-xchange.com
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David.P
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Re: PDF text not being cached?

Post by David.P »

Hello Daniel,

thanks for getting back on this. The system is 64 bit, cf. the benchmark linked above and a summary of the system specification by CPU-Z here:
https://file.io/NWIvIZ1qN4hz

image.png

Hopefully this will help in finding the reason for the slow search on the laptop.

Best regards
David
--

PS: I just realized the fact that I'm using the portable version of PDF-XChange Editor on the laptop. Sure enough, PDFXEdit.exe is reported as 32bit in Process Explorer. Could this be the reason? Is there a possibility to use the 64 bit edition in a portable version?
Last edited by David.P on Wed Jul 13, 2022 5:01 pm, edited 1 time in total.
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Re: PDF text not being cached?  SOLVED

Post by TrackerSupp-Daniel »

Hello, David.P
David.P wrote: Wed Jul 13, 2022 4:53 pm PS: I just realized the fact that I'm using the portable version of PDF-XChange Editor on the laptop. Could this be the reason?
Considering that the portable is only 32-bit, yes that most definitely could be the cause. Please try using the installed 64-bit version of our software instead, and tell me if that resolves the issue.

Kind regards,
Dan McIntyre - Support Technician
Tracker Software Products (Canada) LTD

+++++++++++++++++++++++++++++++++++
Our Web site domain and email address has changed as of 26/10/2023.
https://www.pdf-xchange.com
Support@pdf-xchange.com
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David.P
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Re: PDF text not being cached?

Post by David.P »

Thank you Daniel,

I just was going to say that as a test, I just copied the installed 64 bit version onto the laptop (I do not have administrator rights there) and started it in portable mode. Sure enough, the first search took only 22 seconds, and each subsequent search only about 1-2 seconds as usual.

Problem solved, thanks very much!

Cheers
David
:)
--

PS: as before, the same search in the same file in Ad0be Reader (64 bit) takes several hours 🤦🏼‍♂️🤦🏼‍♀️🤦🏼‍♂️ on the desktop PC, and about 10 minutes on the laptop, every single time. With Ad0be Acr0bat Pro XI (32 bit), the search takes about 5 minutes every time on the desktop PC.
Last edited by David.P on Wed Jul 13, 2022 5:44 pm, edited 2 times in total.
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TrackerSupp-Daniel
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PDF text not being cached?

Post by TrackerSupp-Daniel »

:)
Dan McIntyre - Support Technician
Tracker Software Products (Canada) LTD

+++++++++++++++++++++++++++++++++++
Our Web site domain and email address has changed as of 26/10/2023.
https://www.pdf-xchange.com
Support@pdf-xchange.com
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