Bridge is slow because it's only using two threads

Question

I'm finding that Bridge (CS6) exhibits very poor performance when building 100% previews, I think the software is limited to only two threads.
If you load bridge and go into a folder with some images and then Tools->Cache->Purge you'll see that Bridge takes a long time to rebuild the previews even on a high end machine, especially if you have both "Always High Quality" and "100% Previews" selected. I think the problem is that it appears to build the previews using only two threads on the CPU, so while a 2005 dual core machine might get maxed out, a Quad Core, or 8 Thread, or even 12 Thread machine sits there mostly idle while Bridge grinds away for an hour or more.
It's easy to check this, just load up Windows Task Manager, and view the "Processes" tab and Bridge will only ever use 2 threads worth of CPU cycles, i.e. 50% on a Quad Core, and 17% on a 12 Thread high end desktop. I've seen the problem with JPG files, PSD files, and NEF files (Nikon RAW). The processing time of large Nikon D800E NEF files is very slow. After shooting 900 images I can expect the preview build time to take over an hour on a super high end machine with loads of memory, storage IO, and CPU cores and threads, all because it appears bottlenecked on software design. Meanwhile the machine is only running at roughly 20% utilization, the memory barely used, and the IO system close to idle.
I'm using Windows 7 Ultimate 64-bit, 64GB RAM, 12 Thread Core i7 3960X at 4Ghz, two Nvidia GTX470 graphics (in SLI), a 2-way RAID-0 SSD storage array for the OS, and an 8-way RAID-0 SSD array for the photoshop work files. The hardware is clearly not the issue. Although, just to check, I confirmed the same problem exists on a simple Win8 Core i7 system, and a Core i5 laptop.
Even worse, after waiting an hour to build previews for 900 images (3 seconds each), after adding GPS data, or after making edits in Camera Raw it then needs to rebuild all the previews again, this is understandable, but super fustrating when you know it's not working as fast as it really should be.
To be clear, I'm not upset it takes 6 seconds per image per thread - there's a lot of work to do, especially with D800 files. But I'm upset that Bridge's software design only uses 2 threads, and thus limits performance to building a preview every 3 seconds, when in fact it could be working 6 times faster on a PC with 12 thread, and I find it shocking that Adobe's latest software wouldn't be optimized for anything more than a dual core CPU, wasn't quad core launched in 2006?
Roland.
P.S. for any Adobe Tech's reading - I submitted this under case number 184020852 and there's an attached PDF in the ticket including several screenshots.

Answer 1

There have been many discussions in Photoshop forum about processor speed and multicores.  I know Bridge is not Photoshop but it may give you some insight as what is going on.  Photoshop has supported multithreading since CS3.  Here is a quote from Adobe Tech Note:
Photoshop generally runs faster with more processor cores, although some features take greater advantage of the additional cores than others. There is a law of diminishing returns with multiple processor cores: The more cores you use, the less you get from each additional core. Therefore, Photoshop doesn’t run four times as fast on a computer with 16 processor cores as on a computer with four cores. For most users, the increase in performance that more than six cores provides doesn't justify the increased cost.
I run embedded thumbnails (therefore 100% previews are off) as they take up less space and are the fastest to load.  I ran a simple test with Bridge CS5 (32 bit) and CS6 (64 bit) on one folder of 200 video images totaling 16 gigs, or 80 meg per file.  With folder loaded I clicked Tools/Cache/purge cache for xxx folder.  I then timed the rebuild until the arrow stopped spinning in lower left hand corner.  For CS5 the time was 35 seconds.  For CS6 the time was 72 seconds. 
I then took a folder of 1147 jpg images of 660 meg (427k/image).  In CS5 it took 12 seconds to build the cache, and the same for CS6.  However, the interesting part of this is when I loaded this folder in CS6 I had never been there before so it had to build it.  THis took 80 seconds.  When I purged it an it rebuilt it took 12 seconds.  I have noticed this phenomemum before where the initial build takes 5-7 times longer than a rebuild of the cache.
I then ran the same test with the still images with 100% preview and Always High Quality.  With CS5 it took 3 min 30 seconds and with CS6 it took 5 min. 20 seconds.
So with these very SIMPLE tests I conclude that CS6 has quite a bit slower cache process than CS5.  As we have all learned with buying new products, new and improved does not always mean it is better.