1 2 Previous Next 27 Replies Latest reply: Mar 30, 2014 5:18 PM by Murdock Troon
Adrian.88 Level 1 Level 1 (0 points)

Everytime i try to read a long pdf file in preview the scrolling is very slow and it makes it unreadable. I have already search for a solution in the web but couldn't any.


Can anybody help me?



MacBook Pro, Mac OS X (10.7.3)
  • 1. Re: Very slow scrolling when reading pdf file.
    ezollars Level 2 Level 2 (255 points)

    How long are the PDFs you are looking at?  I've got a full version of Acrobat installed and I don't notice any speed difference in scrolling between Acrobat and Preview.

  • 2. Re: Very slow scrolling when reading pdf file.
    Adrian.88 Level 1 Level 1 (0 points)

    It is almost 400 pages long. In my desktop pc i can see the file just fine, no problem with the scrolling. I work with long pdf files a lot and this is very annoying.

  • 3. Re: Very slow scrolling when reading pdf file.
    ezollars Level 2 Level 2 (255 points)

    Can you do a Get Info (Command-I with the file selected in Finder) and let me know the file size of the problem file?  I've got a 520 page PDF loaded up in Preview right now and it's moving instantaneously from page to page.  However, the PDF is not a large scanned document, but rather is a book that is printed to disk and is mainly text in nature--so its filesize is at 7.1MB.


    The fact you don't have the issue on the desktop seems interesting--I don't notice a difference between my MacBook Pro, a MacBook Air or an iMac I've run a quick test on.

  • 4. Re: Very slow scrolling when reading pdf file.
    Adrian.88 Level 1 Level 1 (0 points)

    I really appreciate your interest.


    The file's size is 36.7MB, it's a long pdf. I don't know why i said it was 400 pages long, this one i am looking at is 1000 pages long, anyway with the 400 pages long i also have problems. The file has got just text and a few diagrams, It's university book to learn how to program in java, it's not scanned.


    The desktop pc i mentioned before is not an imac, it has windows installed.


    In adition my 2 week old macbook pro has Intel Core i5 2.4GHz and 4GB of ram. It has OS X 10.7.3 installed.

  • 5. Re: Very slow scrolling when reading pdf file.
    ezollars Level 2 Level 2 (255 points)

    Hopefully someone else will also have ideas, but I'm wondering if Preview is waiting on the disk, is chewing up the CPU or just sitting there but not showing anything.  If you send it to the end of the file does it go there instantly or does it hang up?


    I'd suggesting loading Activity Monitor and sorting by CPU usage, along with displaying disk activity at the bottom and see which one (if either) appears to be where Preview is concentrating while it's hung up.


    It might relate to the preference file (weird things sometimes hit there), but I suspect you could eliminate that if you temporarily created another user account and opened up a problem PDF there.  That way you could see if the problem seems linked to the account.  If it does, you could try deleting the Preview plist file in your user Library folder (Preview should recreate it if it's missing).


    If you create a pure text PDF of about the same number of pages (if you have a large text only document you could import it into TextEdit, Pages, Word, etc., copy/paste it into itself enough to get 1000 pages, then print to disk) you might look at that as well.  It's possible the file contains some graphics structure that might be slowing things up, though I'd think that would only show if you passed by a page with that sort of graphic. 


    I suppose one final test (though I don't really like it) would be to obain Adobe's Free Reader for the Mac and see if that has the same problem or not.  I don't like that because Adobe may want to claim all PDFs by default, forcing you to swap it back if you want to go back to Preview, but it might help.

  • 6. Re: Very slow scrolling when reading pdf file.
    SCLR46 Level 1 Level 1 (5 points)

    I've had a similar problem with PDFs in both Acrobat and Preview for some time, but found an effective (if bizarre and slightly annoying) workaround. 


    I've found that if I open the trouble PDF in Preview, then select File > Print > Save as PDF, overwrite the original file, then close/reopen the PDF, suddenly the PDF is liquid quick when scrolling.  It's strange.  This seems to have something to do with how Acrobat generates the PDF versus Preview. 


    The annoying part is that I find myself manually repeating this process for a lot of PDF files that I deal with for work.  I would *love* to discover a macro or Automator script that would let me batch "print as PDF" a bunch of slow-scrolling PDFs.  If anyone has any ideas, I would be eternally grateful...

  • 7. Re: Very slow scrolling when reading pdf file.
    lazarusnine Level 1 Level 1 (0 points)

    Like SCLR46, I have the same issues. Saving by 'printing as PDF' works wonders, but it also makes the file size a lot larger in my experience. I had one scanned file, which was only around 10 MB and the scrolling was atrocious. I printed as PDF and the scrolling speed vastly improved, but my file size was then 40 MB. Applying a Quartz filter is not really an option, because the 'smaller file size' results in one that is pretty unreadable. Another tangental complaint is the fact that custom quartz filters no longer appear in Preview's drop-down menu. You have to open the document with the Colour Sync Utility in the Utilities folder. Ridiculous. This hasn't helped much, but at least there's a solution available to you (even if it's not exactly ideal).

  • 8. Re: Very slow scrolling when reading pdf file.
    Shootist007 Level 6 Level 6 (16,640 points)

    Simple fact is the MBPs uses a SLOW 5400RPM drive. this can and does slow the whole system down. The complete PDF is not loaded into menory when first opened so it has to load new pages from that SLOW HDD. On your PC it more then likely has a 7200RPM HDD which will load new pages much faster. And the way Windows handles the caching of those pages when the file is first opened. OS X like to keep everything that has ever been opened since the system was booted in some type of memory space making it harder for new things to get loaded. They do that just incase you might want to veiw or re-open a program or file.


    Try actually quiting some of the stuff the OS X like to leave open, like any and all programs you have opened since boot.

  • 9. Re: Very slow scrolling when reading pdf file.
    Greebojoe Level 1 Level 1 (0 points)

    To Shootist007, nice idea but drive RPM doesn't make THAT much difference from the speed difference the OP has quoted.


    I currently am working to get to the bottom of this problem myself , and just to prove that the drive speed is not at fault here.. i am using a MBA's Solid State Disk, and the lag is definately noticable and in my view unacceptable, even on a 700 page 20Mb file... My cpu is asleep , and i have tons of both free and inactive RAM just waiting to be used.. so i have to start thinking down the line of it being how Preview manages the viewing of certain PDF files..

  • 10. Re: Very slow scrolling when reading pdf file.
    sca Level 1 Level 1 (0 points)

    Agree! RPM is not the problem.


    I use a MacBook Air and I my PDF files (Marantz SA8004 and Denon DBP1611 manual) is not that long (3.7 MB) and preview is toooo slow. I give up reading those files on Mac..

  • 11. Re: Very slow scrolling when reading pdf file.
    Greebojoe Level 1 Level 1 (0 points)

    In reply to sca's post..


    For your Marantz and Denon PDF Manuals.. just do as user SCLR46 suggested, opening the files in preview and re-saving them , it REALLY DOES work well... and even IF they quadruple in  file size , 16mb is nothing nowadays.. enjoy ..

  • 12. Re: Very slow scrolling when reading pdf file.
    appisntworking Level 1 Level 1 (0 points)

    Do you know of the quickest way to do this resaving method with multiple files? It is the only way I have come across that works. Thanks

  • 13. Re: Very slow scrolling when reading pdf file.
    ccstaggs Level 1 Level 1 (0 points)

    Hey, I found something out that is interesting that may help you. I found that when I have "Continous Scrolling" turned on it is slow most of the time and uses up to 88% of CPU when scrolling. When I channge it to "Single Page Scrolling" I never saw it go about 34% and it doesn't appear to be slow. I turned on the thumbnails to the left for each page and scroll through them and the pages on the right update instantly and don't appear glitchy.


    My preview was slow scrolling on PDF files as small as 200k with like 11 pages. That PDF was scanned receipts from my iPhone...you'd think it wouldn't be slow and glitchy when scrolling but it is. I'm kinda doubting that this issue is a computer problem but rather a PDF problem. The pdf format has a plethora of compression settings and image formats that the PDF can contain. I have a technical publication from work that is over 4000 pages and it scrolls just fine. It is not a scanned PDF, it's all strickly text based and line art schematics. It loads instantly and I have no issues with it, but an 11 page 200k file scanned from my iPhone of 11 very small receipts is glitchy. LOL


    Example. You have a 500 page book that you scan and the scanning program take a JPG picture of the pages. Even it it's black and white scan, it's still a picture. You are loading 500 pictures basically. On the other hand, if you could get the source document with the fonts like the master Word document and export to PDF, it will basically flatten and export just the text as a Font and that's how you get (in my case) a 4000+ page PDF that's less than 60 MB. I really think thats the issue with this problem is the way the PDF is created...Adobe really doesn't streamline or standardize the format. I hope that helps, but basically I haven't been able to find a solution, other than turning off continous scrolling like I said.


    If you get this post, try it and let me know if that changes anything for you. Have a good one!

  • 14. Re: Very slow scrolling when reading pdf file.
    possumdesign Level 1 Level 1 (0 points)

    In my case - Snow Leopard and Acrobat Pro 9/10 - the problem was related to a program called RightZoom. If this program is installed together with Acrobat, you have either to deactivate it or add Acrobat in the exclusion list of RightZoom. I did the last and Acrobat now behaves as it should. I found the hint here: http://forums.adobe.com/message/4110934 . It seems that this works with the Reader too.

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