Work in 16bit? What beast of machine you've got?

[samimg]

Hi all,

I'd love to work in 16 bit for its benefits of image quality (no fine noise when doing frequency separation, less banding etc).

I've got a Mac Pro Quad 2.66 / 8GB RAM, with separate internal hard drive as a scratch disk. Everything's fine when working in 8 bit, even large files from digital backs with lots of layers.

In 16 bit, image approx 6000x4000px, even a couple of layers slows down everything, but especially saving to an unacceptable level, it's a couple of minutes to save. I like to save a lot so I just end up working in 8 bit.

I've tried working in 16bit on a 2009 8 core Mac Pro Nehalem too, it was faster, but still noticeably slower than 8 bit.

If you work in 16 bit only, and are happy with the speed, what monster of a machine have you got?

[Florin]

Hi. I made some tests on the job I`m doing right now:
1. image size is 4800 x 6844 pixels, 800 dpi, background and 1 layer (work on background and have the layer as an untouch original file, for compare), PShp indicates Doc31.3Mb/62.7Mb on 8bit/channel, gray scale
I did some brush strokes and saved: 1.5 seconds
2. changed to 16 bit, gray scale, size changed to 62.7Mb/125.3Mb, did the same and saved in 10 seconds.
3. changed to RGB, size is now 188Mb/376Mb, saved in 32 seconds.
If I`m not whrong, the doc size has 2 values, physical/disk.


My system is:
MSI K9N2 Sli Platinum motherboard
Phenom II x3 720 BE with Thermaltake Venus 12 cooler, 3200 Mhz
8Gb (4x2Gb) Patriot PVS24G6400LLKN Extreme Performance Viper Series PC2-6400 CL4 DDR2-800 Dual Channel
MSI nVidia GForce 9600GT / DDR3 512 Mb
x2 WDigital Caviar Black bulk / sata 300 / 32Mb cache / 750Gb each
DVD-RW Plextor px-810SA
PS Xion Power Real 2.2 / 600W
Aluminium case Viper XG with x3 120mm Ever Cool Spider fans (front, back, up)
1 monitor LG Fantasy 19" / 4:3
Logitech 2.1 sound system
Microsoft keyboard
Microsoft IE mouse
OS Windows 7 Ultimate x64

Regards

[andrewrodney]

Any machine will run the 8-bit faster so its difficult to not be affected by this speed increase. That said, the speed hit is well worth the possible quality benefits and archive properties of high bit (16-bit) data. See http://www.digitalphotopro.com/gear/...-decision.html

[DJSoulglo]

Get a buttload of RAM, run CS5 (it's a LOT faster than other versions of PS). Be patient.

[Florin]

I agree about the RAM, look for compatibility brand and top quality. Since I changed for Patriot y have an almost perfect system. I had before a Corsair Twin DHX and my workfow was a hell. Crashes and lost files, video probems, BSOD and so on. This Patriot is the best of the best for my DDR2 mobo. Never failed and I`ll not change to DDR3. I`m happy with it.

[samimg]

Florin - Your test proves the time spent saving raises exponentially, imagine you add 10 more layers with masks, some adjustment layers with masks, etc and everything slows down to crawl.

Andrew - Really informative article, thanks. I agree on the benefits of working in 16 bit, but it comes at a price of extra time spent waiting! Or at the price of new 12 core Mac Pro??

DJSoulglo - Good to know that about CS5 mate!

[Florin]

How many Mb has your "slow" file?

[BriPriUK]

3. changed to RGB, size is now 188Mb/376Mb, saved in 32 seconds.
If I`m not whrong, the doc size has 2 values, physical/disk.

Hi
The first size is the size of the flattened file, the second the size including layers.

Brian

[Quantum3]

Have an oct-core with 8GB of RAM and happens the same to me. It's not the amount of cores, as far as I understand what you write, but how the amount of RAM is being used. 8GB seems to be a lot, and it's, but an image with tons of layers (even in 8 bpc) demands too much RAM. Also, there is a damn bastard app running on the background called mdworker that sucks all the RAM, specially when saving. At the least, 2 GB of RAM are sucked by that damn app till around 3.5 or so. This app is the cause of the problem. I have found it related to the QuickLook app and the indexation of the file for spotlight, but I have configured the Spotlight to not index PSD/TIFF but mdworker still active.

If someone knows how to kill the mdworker or something related, drop a line!

Mart

[Florin]

One of the tricks to accelerate your disk(s) is to desable the Windows index service. Right clic over your C: / Properties / and uncheck the idexfiles service. This stuff is usless. I saw this years ago in a lot of hardware and software forums and it's fine. You`ll win some 25% more disk speed.

[samimg]

Quantum - Good to know about this mdworker.. I'm going to watch it today, see what it does.
Florin - I don't know much about Windows, but can you still search when you disable that?

[Quantum3]

Keep the Activity Monitor opened and you will see it.

[Florin]

On all Windows systems there is a process / service named MDM - "Machchine Debug Manager" but I ignore if it is the same but called by Mac's "mdworker". The fact is that on Win it is holdind very few Rams.
Here I found something about: http://discussions.apple.com/thread....46203&tstart=1
Anyway, Google is your first option to find some forums and read about.

On Win, it`s very easy to desable this both from the Task Manager or Control Panel/Administrative Tools/Services.
You should also desable the indexing service (if you have it on Mac), it runs on background and it really is usless, supposed to accelerate the searching on your HD, when you're looking for some file.

[kav]

If you really want to use 16 bits per channel, anything not done directly on image data but via use of masks is pretty much fine to do on an 8 bit copy. Say curves, selective color, brightness/contrast, softlight or color dodge painting layers, etc. can be done on an 8 bit copy then duplicated. A lot of expensive labs still work on images at 8 bits per channel, so it's not to say that you can't produce printable artwork without working at maximum bit depth. This is just kind of a work around that I use if an image is being processed conservatively and adjusted massively in post. Also not sure if you're working in RGB or CMYK. Having to deal with a 4 channel image at 16 bits per channel is painful.

[Quantum3]

I've been using Microsoft Office on my mac and never had a problem with the mdworker app. It's only noticeable when working/saving big files on PS (400MB-1,5GB on disk, 5-7GB on memory) and it doesn't affect the cores, just the RAM.

[samimg]

I've been testing the mdworker in Activity Monitor, it's quite well behaved on my machine.. Even when saving 1.2 GB file to disk, it only eats up a couple of MB and a fraction of processor speed. I run OS X 10.6.4, no Microsoft Office installed.

What is strange though, that only a small part of time consumed when saving layered 16 bit is actual writing to the disk.. Most of the time (sometimes 3-5 mins) disk is idle, but Photoshop is at 100% or even something like 100.6% of CPU.. Strange.
I guess I only find out whether I can speed up the machine at all by getting CS5 and more memory.

Kav - Let's say you do a soft light layer or a painted mask using tablet with pressure sensitive opacity/flow etc in 8 bit. I think if you did the same thing in 16 bit the mask would have less banding in it/be smoother. So you only have half of the advantage when you convert to 16 bit afterwards and paste in a fresh 16 bit background.

And I agree you can produce printable artwork in 8 bit, I've been doing it for years!

[kav]

Originally Posted by samimg

I've been testing the mdworker in Activity Monitor, it's quite well behaved on my machine.. Even when saving 1.2 GB file to disk, it only eats up a couple of MB and a fraction of processor speed. I run OS X 10.6.4, no Microsoft Office installed.

What is strange though, that only a small part of time consumed when saving layered 16 bit is actual writing to the disk.. Most of the time (sometimes 3-5 mins) disk is idle, but Photoshop is at 100% or even something like 100.6% of CPU.. Strange.
I guess I only find out whether I can speed up the machine at all by getting CS5 and more memory.

Kav - Let's say you do a soft light layer or a painted mask using tablet with pressure sensitive opacity/flow etc in 8 bit. I think if you did the same thing in 16 bit the mask would have less banding in it/be smoother. So you only have half of the advantage when you convert to 16 bit afterwards and paste in a fresh 16 bit background.

And I agree you can produce printable artwork in 8 bit, I've been doing it for years!

I've done it both ways. For my purposes the photographic data would be where I'd be concerned about banding. Even if my masks developed a minor amount of banding it wouldn't worry me much. If it's really difficult painting, I haven't found bit depth to be the determining factor. I have made larger copies of an image just to make painting masks easier. It isn't a perfect solution but it's just annoying when going from 2 pixels to 3 pixels gives you an effective 50% increase on brush size. Between adjusting the shape and going to a higher bit depth, neither solved the problem in the same way for me. I could see it being more necessary with hdr tone mapping.

[Quantum3]

Originally Posted by samimg

I've been testing the mdworker in Activity Monitor, it's quite well behaved on my machine.. Even when saving 1.2 GB file to disk, it only eats up a couple of MB and a fraction of processor speed. I run OS X 10.6.4, no Microsoft Office installed.

What is strange though, that only a small part of time consumed when saving layered 16 bit is actual writing to the disk.. Most of the time (sometimes 3-5 mins) disk is idle, but Photoshop is at 100% or even something like 100.6% of CPU.. Strange.
I guess I only find out whether I can speed up the machine at all by getting CS5 and more memory.

Kav - Let's say you do a soft light layer or a painted mask using tablet with pressure sensitive opacity/flow etc in 8 bit. I think if you did the same thing in 16 bit the mask would have less banding in it/be smoother. So you only have half of the advantage when you convert to 16 bit afterwards and paste in a fresh 16 bit background.

And I agree you can produce printable artwork in 8 bit, I've been doing it for years!

So strange... So you checked the mdworker and it was fine but you found the mac slow anyway?

PS: If you're getting the SBBOD for about 10-25 secs when this happens to you, probably you need to reset your finder.plist