CS4 32-bit vs. 64-bit -- some thoughts

[mdavis]

Having built a new high performance (for now) computer a few months ago, I upgraded my Photoshop CS3 to CS4 and installed it in the new box.  In the process of using CS4, I have learned a few things that may be food for thought among those of you with 64-bit operating systems and CS4.

If you have both, you probably already know that Adobe installs both a 32-bit and a 64-bit version of CS4 on your computer by default.  Both versions boot in about the same time (2-3 seconds on my system), and the menus and features are essentially the same.  The main advantage I can see with CS4-64 is that it handles much larger files and can use more than 3.2 gigabytes of memory, which is an operating system feature, not necessarily CS4.  This gives CS4-64 a speed advantage in working on some files, though probably not smaller files.  Both versions are said to support multi-core processors.

But CS4-32 has some decided advantages over CS4-64:

Most plug-ins that work in CS3 will work in CS4-32 (Curvemeister is, happily, one of these), but few if any will work in CS4-64.

I'm finding that Actions do not often work in either CS4-32 or CS4-64 because of menu changes and/or key assignment changes between CS3 and CS4 versions.  If you re-build an action using the CS4 menus or keys, the same action works just fine in CS4.  You simply have to interpret the steps in terms of CS4 language.

Bridge, now an integral part of CS4 rather than a "stand alone" application, automatically sends images to either ACR or directly to CS4 (depending on your file type and preference settings).  You cannot force Bridge to send images to CS4-64 if you're running it from CS4-32 and vice versa.

ACR has been upgraded incrementally for CS4.  If you are in CS4-64, and open Bridge, it will send images to ACR for preliminary editing and will then send images directly to CS4-64.  In short, CS4-32 loads Bridge-32 and everything is done in that 32-bit mode.  CS-64 loads Bridge-64 and Bridge finds CS4-64 or ACR as appropriate.  Images worked in ACR from within CS4-32 can later be loaded into CS4-64.  ACR does not seem to be version-bit specific, it only sees which CS4 bit-version you called it from and sends it images to the loaded version.

When using scanner input, it is possible to send images to CS4-64.  However, after finding the scanner input option missing in the Files-Import menu in CS4-64, I did some digging and found out that the only way to directly input scanned images directly to CS4-64 is to use the WIA import option within CS4-64 to point to the scanner.  Then, the only capture format available is bitmap (.bmp) images.  The reason for that (I discovered) is not the fault of CS4, it has to do with the fact that TWAIN, which is the interface that your scanner uses between its own scanner software interface and CS4, does not support 64-bit.  Therefore, you will find the scanner input listed in the CS4-32 File-Import menu, but not in CS4-64.  All scanner functions are "normal" in CS4-32 assuming you have 64-bit drivers for your scanner installed.

For the time being, if you are interested in quick workflow and application integration, you are going to use CS4-32 where Curvemeister lives.

[derekfountain]

For the time being, if you are interested in quick workflow and application integration, you are going to use CS4-32 where Curvemeister lives.

My experience with 64 bit computing has only been through Linux, so it's not exactly on topic, but it basically echos this post. 64 bit Linux came out about 4 years ago when the first 64 bit CPUs appeared, and the same sorts of problems where exposed as Photoshop is seeing now. Basic compatibility was maintained by installing both 32 bit and 64 bit versions of things, with the hope that some clever semantics would ensure that the right version of a program, library or plugin would always be picked up based on the context it was used. In practice this mostly worked, but wasn't quite perfect.

In the Linux world you can frequently get around problems by grabbing the source code and compiling it yourself in the mode you want, assuming you have the skills to do that. But even so, closed source things like Java, Flash and so on still presented problems. In the Windows world, where pretty much everything is closed tight, it's going to be a longer and more painful journey.

After a couple of months I came to the same conclusion about 64 bit Linux that mdavis has apparently come to about Photoshop: it doesn't work properly and it's better to stay in well understood, well supported 32 bit land unless you have a compelling reason to switch. On my Linux desktop I honestly couldn't see any performance difference between 64 bit and 32 bit, so I wiped my 64 bit Linux setup and put the 32 bit version back. That was 3 years ago, and I'm still running a 32 bit OS on 64 bit hardware.

Things have matured a lot in the 64 bit Linux world since then, and it's probably now a perfectly workable system. I suspect 64 bit Photoshop will mature quicker because there's a much more compelling technical argument why people would want it - performance on 64 bit systems will be better, if only because of the larger memory space. But I would suggest people proceed into 64 bit land with caution. The fact your 32 bit plugins like CM might not work is not likely to be the only problem you'll encounter.

[mikemeister_admin]

I've run Vista x64 since this July, and PS x64 for a few weeks, so thanks for initiating this posting. Yes, plugins and drivers, that's for now a bit of a bitch with PS x64. However, aside from that, I have found PS x64 to be a wonderful application for really large files! I now have 16 GB of RAM in my desktop and Photoshop CS4 x64 "sees" close to 15 GB -- i.e., it regards the almost-15 Gb as 100% -- and it purrs like a cat in a field of catnip!  Even crazily huge, multi-layered panorama photos are now quite endurable to work with. I have not yet encountered any particular "issues" with this new x64 build, so I don't think there's any reason to be so cautious as you guys seem to think is necessary. I personally find the 64-bit part is THE killer "feature" in CS4 -- with Content Aware Scaling being second in rank -- and I'm really grateful to Adobe for having given us Windows people this new "feature": amazing speed with huge files.