# RAID 0 ... would one notice any speed improvement?



## rNeil (Jun 5, 2012)

Having 'gear' that is decent but not a hot 'gamer' machine for either my wife's or my main workstations, and suffering from some slowness at times especially such as importing shoots, re-making/re-drawing previews, or applying multiple changes to multiple image files ...

Would a stripped RAID-0 array add any noticeable speed increase? I've read that in PS, it's really only noticeable whilst loading large files or editing video. Lr seems to do quite a bit more forth-and-back to disc and RAM, however. We've both got SSD drives for system and NEEDED programs (like all Adobe), and standard SATA drives for all else. So, someone suggested using a stripped-array pair for image files, but I don't know if Lr writes back to the image drives enough worth doubling the drives number for working files. I'd think it's more a RAM issue?

Neil


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## erro (Jun 5, 2012)

Don't know about RAID, but I would strongly suggest that you put the LR catalog (and associated previews) and cache on a SSD-disk. LR reads and writes to the catalog, previews and cache all the time. The original images are only read now and then, for example when opening a photo in the develop module, but I don't think that is worth spending SSD-disk-money on.


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## donoreo (Jun 5, 2012)

From slowest to fasted : hard drive - > RAID 0 - > SSD.  That is just from a hardware perspective, so yes, RAID 0 should be faster but how much is noticeable, is hard to say.


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## Paul Treacher (Jun 5, 2012)

Neil

I once forgot to set my raid up before reinstaling windows on a previous PC. The result was Windows and applications took twice as long to load so for overall PC performance it does make a big difference however as you already have these on SSD then I dont think it will make to much difference unless you are regularly importing large numbers of large files. When loaded individual images into the develop module you are only talking about a few seconds - does this really matter to you? If your using a PC which has RAID support built in a merely needs to be switched on and this wont involve to much work re-instating your files then I would do it anyway however if it involves spending money on new hardware then I dont think I would - put the money towards you next PC which will, of course, come with raid , wont it ?

Paul


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## rNeil (Jun 6, 2012)

We have SSD drives for system files and as FEW programs as we can keep that drive to, including as noted all the Adobe programs. I don't know if it's really big enough (only 60 gigs, and I'm TICKED at how many programs no longer allow you to install where YOU choose to and demand to be on the system or "c" drive ... grrr ... ). Most programs can live just happily in the "Program Files x86" folder on a regular old hard drive in the computer, they don't need the speed.

My Lr cats are on a standard hard-drive. Currently, I've only 18 gigs free on the SSD, and two Lr studio catalogs (one my personal professional files, one the studio I share with my wife) each with around 7.5 gigs to them. That would seem not ... easy ... to fit onto the SSD. My wife's complete studio catalog for her work is currently above 12 gigs ... and she's got no room in the inn on the SSD. Maybe ... we need MORE SSD drives ...

Neil


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## erro (Jun 6, 2012)

New SSD-drives for the cataloges, just go for it. Having the program on SSd isn't all that important (I mean, does it matter if the program takes 20 seconds or 2 to start?). Having the working data (the catalog in LR's case) is a huge difference though, since this data is constantly read from and written to.


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## thedge (Jun 7, 2012)

I would go SSD over RAID0 any day. If youre set on RAID0, have a religious backup routine. In RAID0, a single hard drive failure and all your data is lost.


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## erro (Jun 7, 2012)

And with two disks, the probability of one failing is twice as large than if you have just one disk.


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## rNeil (Jun 7, 2012)

Thanks for the comments, folks ...  

Using a RAID-0  I am fully aware is not at ALL anything to do with backing-up, but simply a speed issue. As it sounds like a better gain would be an SSD just for the catalogues and Photoshop scratch-files, I think that's where we'll go. Archiving/backup is handled elsewise ...

Neil


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## BigIronCruiser (Jun 13, 2012)

Has anyone seen a significant performance boost in the Develop module by also putting RAW files on a SSD?  Not permanently, but at least until they've been edited?


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## Mark Sirota (Jun 14, 2012)

There's not much to be gained from that, because the raw file is partially processed and that data is stored in the Camera Raw cache. After this, Lightroom will read from the cache rather than from the original, for as long as that data remains in the cache.


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## BigIronCruiser (Jun 14, 2012)

Mark Sirota said:


> There's not much to be gained from that, because the raw file is partially processed and that data is stored in the Camera Raw cache. After this, Lightroom will read from the cache rather than from the original, for as long as that data remains in the cache.



This seems contrary to what Erro said toward the beginning of this thread: "The original images are only read now and then, for example when opening a photo in the develop module".  So, who's right?


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## clee01l (Jun 14, 2012)

BigIronCruiser said:


> This seems contrary to what Erro said toward the beginning of this thread: "The original images are only read now and then, for example when opening a photo in the develop module".  So, who's right?


If the ACR cache contains the data needed, the RAW file will not be accessed.  LR never accesses the original RAW image file directly. So, what Mark and Robert are saying are not in conflict.   Raw files need to be demosaic'd and once done, that result is an RGB image file stored in ACR cache. This is the image file used by LR.  As long as the result is maintained in ACR cache, the original RAW image file is not needed, even for export.  ACR Cache is size limited in Preferences.  Older cached images are dropped off in favor of new additions to maintain a certain storage limit. If the user requests an older RAW file in LR, LR first goes to its own preview cache for a 1:1 preview.  Failing to find one there, it looks in ACR cache for an RGB image file, or if the original is a JPEG or TIFF, it opens the file itself.  If the original file is a RAW file, and there is no 1: preview cache image, or ACR Cache image, them LR calls ACR and demosaic's the original RAW to produce an image it can use.


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## Jim Wilde (Jun 14, 2012)

I don't think it's that straightforward anymore.....

Back in LR2 the individual *.dat files stored in the ACR Cache for my 5DII files (25-30mb) were about 17mb in size.

Currently in LR4, they are now only about 400-500kb each. Even for those two D800 files I downloaded earlier the cache size is only 567kb. I have no idea what that actually now means in terms of opening files in Develop, but because of the longer load times than in Library, I would suggest it ain't the previews being opened....so logically it must be reading from both the ACR cache AND the actual original image.


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## BigIronCruiser (Jun 14, 2012)

Cletus - Thanks for the clarification.  

There are suggestions that putting the Catalog and Cache files on SSD improves performance, but given that individual Preview and Cache files are so small, it's a little illogical that putting them on a SSD would make much of a difference when "Loading" in the Develop module.  Maybe my logic is illogical.

I have a PC with a Core-i7 920 with 8gb memory and multiple HDD's.  I render 1:1 previews, and completely "Loading" Nikon D800 images in the Develop module still takes around 9 seconds.  This is painful, and I'm looking for ideas that might get it down to the 2-4 second range.  I also get temporary hangs (5-15 seconds) when editing, particularly when using spot removal.  The hangs are not unique to large D800 images, as I've also seen the same thing with much smaller D700 images in LR3 and LR4.1.


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## BigIronCruiser (Jun 14, 2012)

After reading THIS article, which includes some verbage on changes in LR4, it seems that SSD's may not be worth the effort.


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## Jim Wilde (Jun 14, 2012)

Ian Lyons, the author of that note, was a bit more bullish about the positive gain from placing the LR Catalog on an SSD in this thread from the U2U forum.


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## clee01l (Jun 14, 2012)

Interesting article, thanks for sharing.


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## Victoria Bampton (Jun 14, 2012)

TNG said:


> logically it must be reading from both the ACR cache AND the actual original image.



Correct.  In fact, it's always required the original raw file, even if the ACR cache exists - which is why it complained when an original was offline and you tried to go into Develop.

The cache files are partially processed data (i.e. demosaic and some early stage processing done), JPEG compressed. I have a vague recollection that it's not full res, but I'd have to check on that. It's the same as the Fast Load Data in newer DNG files.  Consider it a jump start for the Develop module.


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## ukbrown (Jun 14, 2012)

If you have enough RAM then where files are cached can quite often become an irrelevance as once they are read from disk they will be held in RAM.  Windows 7 actively uses any free memory for caching data that is being read from the disk.

Now a lot of people are really anal about data recovery so never have the windows settings of the write caching options ticked.  I have always and never lost any data in five years.  As long as you understand the risks involved, ticking these boxes turns available RAm into a read/write cache for your hard disks and will speed up disk performance quite a bit. 

Try this if you have Windows 7, remember it only speeds up the second read of data and will allow background writes of data to disk, less waiting


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