NAS for photo editing - req'd speed?

[Wombat]

I am planning to build a NAS to use primarily for storing, keywording, and editing photos. Currently, I store photos locally on my desktop workstation, but I would like to be able to access and work on them from my laptop as well, so a NAS is necessary. What sort of NAS speeds are required to 1) keyword photos using a program such as IDImager and 2) edit/convert Raw files (~10 MB each) to JPEGs using a program such as Adobe Lightroom? I know that video editing requires ridiculous speeds to be workable, but I am hoping still photo editing does not. Is anyone using a NAS to edit photos?

If I import a bunch of photos from a shoot and begin making edits to each one, will data have to go back and forth to the NAS with each edit (i.e., every time I move a slider), each time I go to a new photo, or only once when I import them all (and again when I export)? The latter would be the best--I could deal with longer import and export times much more readily than a constant, overall sluggish editing process.

For the moment, I will not get into what I am thinking of spec'ing for the NAS; I just want a rough idea of what level of performance I might need to have satisfactory results. I don't want a NAS if it is going to bring my workflow to a crawl, although I am willing to accept a slightly less snappy response from a NAS than from direct attached storage for the sake of convenience.

Thank you for any thoughts, suggestions, or experiences you can share.

Steve

 

[Jim.Roberts]

Hi Steve

I've built a NAS for exactly that purpose (as well as streaming media). I use NEFs and they run into 20MB+ sometimes. I built a NAS as detailed here. I'll let you know how it performs as I'm going to be setting it up properly at my house tonight. I use PS CS4 and lightroom and I'll let you know what it was like editing with them over the network and what speed it is running at. That should give you an idea of what speed you need if you decide to build your own or buy one.

As for editing, I 'think' PS CS4 and Lightroom store the image in cache when your editing it so it doesn't have to keep moving data about on the disk.

Jimbo

 

[Wombat]

Thanks, Jim! I look forward to hearing your results. I also think that Photoshop (which I will also use with the NAS if things work out) and Lightroom cache images as you suspect.

If it turns out that the speed requirements for photo editing are modest enough, I may eventually buy a consumer grade NAS to use because of the simplicity of set-up and administration, as well as low power consumption. At the moment I am assuming I am going to need/want more speed than a reasonably priced off-the-shelf box will provide, so I am tentatively planning to turn my soon-to-be-retired workstation (3.4 GHz P4) into a NAS--but it will be big, loud, and power-hungry, so I am hoping to be able to retire it quickly.

Thanks again.

 

[Jim.Roberts]

Steve,

The good news is that it works and editing is not a problem.

The bad news is that saving the files afterwards takes an age.

Over my WLAN (802.11g) it reads and writes at about 2.2-2.6 MB/s (17.6-20Mb/s), 802.11g is about 54Mb/s. My LAN on the laptop is limited to 100Mb/s and I manage about 96Mb/s (12MB/s). This is a bit faster but nowhere near the goal of 120MB/s (Gigabit LAN). I reckon it would work OK if I had Gigabit LAN on my laptop.

So the answer to your question is yes it's possible, but you will need a Gigabit LAN to make it work well. At the moment 40MB/s to 80MB/s seems to be the range of commercial NAS. See Tim's comparison here.

Hope this helps ,

Jimbo

 

[Wombat]

Thanks for the update, Jimbo. That is both encouraging and a little disappointing. Most of my work will be on a desktop machine that will be connected to the NAS via gigE LAN, but I will also access the NAS wirelessly with my laptop, via an 802.11g connection. The laptop does have a Draft-N adapter built in, so maybe this experiment will drive me to upgrade my wireless router to 802.11n to see how much that helps.

When I eventually get things set up, I will report my results as well. Thank you again. If anyone else has also worked with photos on a NAS, I think Jimbo and I would both be interested to hear about your experience.

Steve

 

[00Roush]

To my understanding files that are edited over the network are usually copied into a temp file on the client during editing. Only when you save, will the file actually be written to the server. But every program is different in how it works with networked files. Also you could see very different speeds from different programs. Some programs might read/write in 4k increments while others might do 64k which can greatly change how fast files are read/written across the network.

I went ahead and did a few tests on my home network. I opened a 18.5 MB JPEG file that was located on my server. Transfer speed opening the file in Vista photo gallery came in at about 8-12 MB/sec. (based on network statistics) Transfer speed opening the file in Paint Shop Pro (different computer running XP) was about 5 MB/sec. For reference my average file copy speeds between my Vista client and the server are 80-100 MB/sec on large files.

In my opinion most any Gigabit NAS will work good for photo editing. I feel that the program used will have the largest impact on fast files are opened and saved. Using gigabit will most likely help but in my opinion will not make a huge difference unless you are dealing with photo files that are 40 MB+. The files are just not large enough to ramp the speed up. Just my opinion though.

00Roush

 

[Wombat]

Thank you for running that test, 00Roush. I suspect you are right about speed ramp-up for smallish files, so a lot will depend on how Lightroom (for example) handles things. I do think it will copy the files to a local temp directory, but the question is when: if it copies all images on import, or at least when switching over to editing, that will be okay. If it moves each image only as it is "focused on" for editing, then there will be a lag of probably 3-4 seconds going from image to image, which will be rather annoying. I often blitz quickly through dozens of images, so having to wait a few seconds for each successive one to load will be painful--I am getting ready to replace my 3.5+ year-old workstation because even the lag I experience on it going from image to image is enough to be annoying.

I suppose one could copy images from the NAS to a local drive for editing and then syncronize later, but that would create headaches as far as metadata is concerned, as well as Lightroom's database, and it would somewhat defeat the purpose of having a NAS--you could use sneakernet with a big USB stick or drive at that point.

Thanks again, and like I said, when I get around to trying it, I will post my results.

Steve

 

[00Roush]

I am not really familiar with Lightroom. Not sure what you meant about importing. But this might help... Using Paint Shop Pro I opened up 10 different pictures at the same time that were about 6 MB each. From what I can tell all files were temporarily copied to the local machine or at least to local memory. Focusing on any particular picture was very quick. File transfer speed according to the network statistics was 12-18 MB/sec while the files were being opened.

Not sure if that helps or not. Either way let us know how things turn out.

00Roush

 

[Wombat]

I am sorry for using a term and not defining it. Lightroom is built around a database. You cannot simply "open" a file in LR; rather, you have to point it to a file or directory of files so that the LR database (Adobe calls it a catalog) knows where it is. The reason for this is that when you make edits to a Raw file (or add keywords, ratings, stars, or other metadat), all of that information is stored in the LR database in a location associated with the particular image file. Besides being an efficient way of storing things, the setup allows for totally reversible, non-destructive editing of images.

In the version of LR that I have (1.4), I believe that the catalog/database file itself must reside on a local drive, not a network drive, but that may have changed in 2.0. Either version allows images to reside anywhere, which is another reason the catalog/database approach is nice--as far as the end user sees things, everything is in one place (LR) even though the image files may be scattered across various drives, removable media, and network shares.

I will primarily do editing in LR on my desktop, so even if 2.0 (which I plan to get soon) does not allow the database to reside on a network share, that will not matter much. What matters more is how well it will work with the image files on the NAS. (The other program I use to manage images, IDImager, does allow its database to be stored on a network share, and that is the one I am likely to use from both the desktop and laptop.) Of course, if LR 2.0 allows the db to reside on the NAS, then everytime it has to write to the database I may encounter slowdowns, especially with small, frequent writes. I will just have to try it and see how it goes. It may be that I will keep the LR db on the local desktop drive even if 2.0 allows it to be on the NAS--I will still be able to browse images from the laptop through IDI (or Windows directly).

Thank you for asking that question--it has made me start thinking about how things will actually work once I get things up and running.

Steve

 

[Jim.Roberts]

Steve, I now have Lightroom 2.2, so I'll try over the network for you and see what happens.

Jim

 

[Wombat]

Thank you, Jimbo. I look forward to hearing the results.

Steve