The new Camera Raw is a little slower to do the actual conversions - no question.
I expect the improved conversion quality (e.g., more perfect CA removal, better shadow/highlight retention, etc.) to come at some computational cost... There's no reason to think that everything that's newer should also be faster, especially not when it has new features and produces better results. You can be sure the previous versions were highly optimized, making them tough to beat.
I have several versions of Photoshop on the same workstation, a dual quad core Xeon x5460 system (8 cores total)... Here's a comparison of my conversion times:
Times to convert 50 Canon .CR2 raw files converted to 6144 x 4096 x 16 bits/channel PSD files:
- Photoshop CS6 x64, Camera Raw 7.1 RC set for PV2012: 237 seconds (4.7 seconds per file)
- Photoshop CS5 x64, Camera Raw 6.7 set for PV2010: 159 seconds (3.2 seconds per file)
- Photoshop CS4 x64, Camera Raw 5.7: 103 seconds (2.1 seconds per file)
Each file in the newer version seems to take about 1.5 times as long as the previous version to convert, which is quite acceptable from my perspective given the increases in image quality.
Guess we're going to have to start thinking of dumping these old, slow systems and getting some really powerful computers.
Not entire correctly. I have LCD screen on keyboard, that show CPU load realtime. Looks like new conversion module lost multi-thread compatibility. Main problem - CPU didn't loaded fully - ACR 6.6 was able to work at 4 files - new just 1 file. And performance is jumping from 40 -50% to 90 - 95% And for me it looks like serious problem with software optimization. BTW new CA module without manual correction work like dumb auto red eye removal module - if it didn't detect CA that visible on picture - it didn't remove it at all ;( - like module that couldn't for example detect red eye on close face portrait.