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Apple Preview app renders images very slowly

I would really appreciate knowing if other people with Macbook Pros (1st gen) have this problem as well. Snow Leopard is a real drag without Preview.
 
For what it's worth, this is the speed with which Preview renders several very high-resolution pictures on my 1st gen (non-pro) Macbook. Whether it's even possible or not, Snow Leopard doesn't seem to utilize both cores for rendering the JPEGs. :( Since I'm using an SSD, opening the TIFFs on the other hand takes almost no time here.

Are you sure it was that much faster on 10.4 though? I might try it out one of these days - I still have a 10.4 boot disk lying around somewhere.

 
I'm positive that with Tiger, I could flip between images instantly.

It is interesting that TIFF files seem to render much quicker than JPEGs. Even larger ones. I do know that other applications render JPEGs just fine under 10.6. Can you imagine if images loaded this slowly while browsing the web?

So it seems there's something wrong with Preview. Why don't I see more about this obvious problem in a Google search?
 
timelessbeing said:
I'm positive that with Tiger, I could flip between images instantly.
Click to expand...

Interesting. Like I said - I'll try and see what results i get using Tiger on my machine

timelessbeing said:
It is interesting that TIFF files seem to render much quicker than JPEGs. Even larger ones. I do know that other applications render JPEGs just fine under 10.6. Can you imagine if images loaded this slowly while browsing the web?
Click to expand...

I guess most TIFF files aren't compressed, so there's very little for the CPU to do when rendering the file.

Of course, pictures on the web are usually much smaller, so that's really not a fair comparison.

timelessbeing said:
So it seems there's something wrong with Preview. Why don't I see more about this obvious problem in a Google search?
Click to expand...

I also quickly tested my examples under Windows 7, to get kind of a point of reference. Here's the results I got:

Code: 
						Win 7		OS X 10.6

 3,9MB JPEG 3456x2304	A380 cockpit:		3,5s		2s	
18,4MB JPEG 8502x2560	Elliott Smith Wall:	4s		17s
 3,7MB JPEG 4000x4000	ISS: 			3s		3s
23,4MB TIFF 2348x3291	Cheval:			2s		1s
15,4MB TIFF 3200x1600	Earth Map:		5s		1s

So OS X easily beats Win7 for at least 3 of the 5 pictures and loses spectacularly for that one huge JPEG file.
 
OK - I've just completed the same test on Tiger, and what can I say: You're absolutely right...

Oh well...at least we've now got 'Quick Look' which is insanely fast.

 
As your videos show, the difference is night-and-day.
(Please don't compare to Windows ... there's a reason I left it behind :p)

Quick Look isn't nearly as useful as Preview. You can't do slideshows or annotate etc. Preview is a very essential tool for Mac users.

I've tried posting in Apple's discussion forum, and I get completely ignored.
 
Last edited:
After a bit of reading, I think this problem may have something to do with something called QuartzGL (based on reported slow PDF performance in Preview in some circumstances).

QuartzGL uses your graphics card hardware to render graphics instead of the MacOS software (Quartz 2D). In some cases this is quicker, and in some cases is the same or slower. Normally, individual applications decide whether to use it or not.

How do I find out the rendering method Preview is using?

I tried manually turning system-wide QuartzGL on and off (http://www.chromescreen.com/speed-up-omnigraffle-with-quartzgl/), but neither made any difference at all.
 
Last edited by a moderator:
UPDATE

Here's a few more specs in case it helps ...

Software
Operating system: OS 10.6.5 - completely up-to-date. Clean install onto formatted HD.
Preview version. From "get info": 5.0.1 , From "About Preview": 5.0.3 (504.1)

Hardware:
Model Identifier: MacBookPro1,1
Processor Name: Intel Core Duo
Processor Speed: 2.16 GHz
Memory: 2 GB
Boot ROM Version: MBP11.0055.B08
SMC Version (system): 1.2f10

Chipset Model: ATY,RadeonX1600
VRAM (Total): 256 MB
EFI Driver Version: 01.00.068

My hard drive is healthy. Console doesn't show any unusual messages.
Tried:
- turning QuartzGL on and off
- copying Preview.app from the install DVD.
- new user account
- reinstalling OS

I get mostly ignored on Apple.com discussion forums.
Kinda frustrated here.
 
timelessbeing said:
I get mostly ignored on Apple.com discussion forums.
Kinda frustrated here.
Click to expand...

I'm sorry. I'm not sure there exists a solution for this problem. Snow Leopard simply seems to perform these actions a lot slower on (somewhat) older hardware than Tiger did. It may have something to do with a stronger reliance on the graphics card. On current hardware, SL is able to open these pictures practically in an instant. That can hardly be explained simply by the (relatively modest) increase in CPU speed. Of course, the graphics card in your MBP is a lot more advanced than the integrated graphics in my old Macbook, so I would have expected it to handle all of this much better... :confused:

Exposé, by the way, also performs much worse under Snow Leopard than it ever did on previous versions of OS X. Don't ask me why. :(
 
flat five said:
something i saw around here that may/may not help..

right click on preview.app -> get info

there's a checkbox for 'open in 32-bit mode'

make sure that is un-checked.

[edit - here's a link to that thread]
https://forums.macrumors.com/threads/1032612/
Click to expand...

Holy cow! I think you're on to something. All Core Duo machines will necessarily execute Preview.app in 32bit mode. Now, if I check that box on a MBP7,1, it will afterwards open images almost as slowly as the MB1,1 does ... :eek:
 
I don't have that checkbox.

I have also determined that update 10.6.3 or 10.6.4 breaks it. It works fine in 10.6.2.

When I copy Preview.app from my install disc, it is still slow, so I think it is a component of the operating system that causes this.

I tried to submit an Apple Bug Report but I can't figure it out.
 
timelessbeing said:
I don't have that checkbox.
Click to expand...

Of course not. You're using a 32-bit processor, so you're already opening apps in 32-bit mode whether you want to or not. That checkbox is only available on computers with processors that support the 64-bit instruction set. On such machines, almost all of Snow Leopard's applications are capable of running in 64-bit mode, and will do so by default.

There appears to be a bug specifically with the 32-bit implementation of Preview.app.
 
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