Hello!

I live in the Netherlands (Holland) and work with large PDF drawings (originally CAD-drawings). Paper size A0. These PDF-files are vector-based and thus very small in filesize (400Kb). Still when I open the files on the iPad, viewing (zoom and pan) is slow.

I need to make annotations as a preparation to my buildingsite-visit, and when I'm visiting the buildingsite I want to be able to add some more annotations. I have to be able to save the annotated PDF and put it back on my PC.

My best (fastest) viewing experience so far is with iBook, but I can't place annotations with the iBook-app.

ReaddleDocs works fine with text-based PDF's but panning within a PDF-CADdrawing means I'm often confronted with the chessboard-background for several seconds (the app is probably loading the vector-info during those seconds).

With iAnnotate I have the same experience (often waiting for the app to show me the next part of the drawing).

What (fast) app should I try next?

I don't work with CAD drawings. Goodreader ($0.99) is probably one of the best overall PDF apps (even though it is also the least expensive), and it does annotation. Also does a great, and easy job of file management. So, if you are willing to spend a small amount of money, give GoodReader a try, and hopefully it will work with you.

I have seen many, many reviews of PDF readers, and side by side comparisons, and Goodreader is generally either the best, or tied for the best.

I have no personal interest in the company, just an overall great app.

I have heard great things about iAnnotate, and it is also generally very highly rated - but I am puzzled, why the slowdown in speed...

Let us know what you find...

I imagine those CAD pdf files are pretty large.

To help with speed, open the multitask bar by double tapping the home button. Press and hold one of the apps until they wiggle. Press the minus sign on all of them to remove them from memory, though probably the first four or five would be enough.

That will remove all active apps from your memory giving your PDF app a bit more room to work, and hopefully a speed boost. It's what I do with drawing apps when the brushes start lagging more than usual.

I second GoodReader for annotation. It gets very good reviews.

Please download my CAD-drawing and test it within your favorite app. I will post the link as soon as my post count is greater than 3...

2 posts already, this is my third...

If someone has a good PDF reader with annotation functionality, please try to load this file. Zoom in and try panning.

Please leave a reply stating the app you tried and what the results are (quick, slow,...).

http://www.zenman.nl/ipadforum/CAD-drawing.pdf

Thanks!

I tested another app. It's called neu.Annotate (free app).

Loading the image after panning is faster than all the other apps I tried. It only takes about 2 seconds before the screen is fully filled again. The scroll-distance when sweeping is a bit limited though. Maybe that partially explains why it is faster, it only has to load a small portion...

I tried it in GoodReader. Using the faster PDF engine (can be selected in settings) it takes a couple seconds to redraw the screen when scrolling, not too bad. No crashes, which they say may happen using that engine. I also turned off the Higher Quality images and Textured background, which it says is slower. The pdf was still clean and readable.

Actually didn't see that big a difference between the two engines.

Anyway, I added a couple of bogus annotations. It was easy enough once I figured out how to do it (tap and hold for annotation menu, do it again on the annotation to change properties)

Here is your file back so you can check compatibility.

http://dl.dropbox.com/u/17742163/CAD-drawing3.pdf

File linked, because apparently it is now too big to attach.

Originally Posted by twerppoet

To help with speed, open the multitask bar by double tapping the home button. Press and hold one of the apps until they wiggle. Press the minus sign on all of them to remove them from memory, though probably the first four or five would be enough.

That will remove all active apps from your memory giving your PDF app a bit more room to work, and hopefully a speed boost. It's what I do with drawing apps when the brushes start lagging more than usual.

iPad does not do true multitasking, it only saves a file of the app's current status, so you can resume where you left off. These files will be small to insignificant for the most part. The RAM available to the system in the iPad is simply not going to allow for large graphic content.

Cheers,

However the iPad does leave the most current apps in RAM, until the memory manager removes them to make room for other stuff.

This is easy to test. Get a system info app. I use Systeminfo. Open it and view your active RAM. Open the multitask bar and start deleting apps. For the first few (left most) apps you will get a significant increase of free memory. After that you get little or nothing back.

While I agree this should not effect performance, and usually does not, I have found that response time in some of my drawing apps is significantly improved by removing all other apps from memory. Perhaps with more memory the apps in question automatically take advantage of it. No way of telling.

So, if you need some extra speed this is worth trying at least once. Maybe it will help with that app, and maybe not. But it doesn't cost anything to try.