RAID 0 and SSDs

[DeeEss]

double post sorry.

 

[DeeEss]

Separation gets around the bottleneck that will occur when the application and scratch are running simultaneously (disk is trying to read say PS, and write the scratch data at the same time; the disk's available bandwidth is shared this way). Even if it's a stripe set, as random access performance (what an OS/applications disk needs), doesn't scale as sequential throughputs do (in fact, there's very little gain, whether it's one disk or n in the case of random access performance). Stripe sets do scale to ~ n disks * performance of a single disk in the set for sequential access only.

Thus better performance is possible, particularly for scratch, when it has it's very own location that's not shared with anything else.

Another alternative for scratch, is a single, inexpensive SSD. It's a bit faster at sequential access than a pair of 2 or 3TB mechanical disks (even more of a difference with smaller capacity disks; based on the fact most SSD's can do ~250MB/s for sustained/sequential throughputs; ~70MB/s for random access).

The same goes for the OS/applications disk, as SSD's have the best random access performance of any drive technology (mechanical is doing good to reach ~40MB/s in this area). It's just using the advantage of it's random access performance for this particular usage instead.

Thanks Nanofrog, your answers are always 5 star answers.

Could you please give your opinion on this:
My plan was for 2x 100GB OWC RE's in a Raid0 array for boot/app/scratch. And 4 disk 12tb Raid0 for Data. But with this new info I wonder if infact I could stretch my resources further and only use one of the SSD's for boot/app and then put Scratch on the 4 disk 12TB Raid0. I have 24GB of RAM so the scratch won't be used heavily, unless I have misunderstood things. Could it be that the performance won't suffer that much?

That Leaves me with an SSD that I can use elsewhere in another machine.

Thanks in advance,

 

[nanofrog]

Thanks Nanofrog, your answers are always 5 star answers.

NP.

Could you please give your opinion on this:
My plan was for 2x 100GB OWC RE's in a Raid0 array for boot/app/scratch. And 4 disk 12tb Raid0 for Data. But with this new info I wonder if in fact I could stretch my resources further and only use one of the SSD's for boot/app and then put Scratch on the 4 disk 12TB Raid0. I have 24GB of RAM so the scratch won't be used heavily, unless I have misunderstood things. Could it be that the performance won't suffer that much?

That Leaves me with an SSD that I can use elsewhere in another machine.

Thanks in advance,

The only reason to stripe a pair of SSD's for an OS/applications disk, is if you can get the capacity cheaper than a single disk (and you can spare the additional SATA port). That's it.

Now as an OS/applications disk is primarily read, you don't need the additional over-provisioning of the RE series either. Nor do I see a reason you need 200GB capacity, unless there's a massive amount of libraries I'm not aware of (but even if there are, you could go for the 240GB Pro series instead, and save $70USD). If you don't have such a library, then the 120GB Pro is probably overkill.

Using 4x 3TB in a stripe set for scratch is also overkill. Use smaller disks if you're going with mechanical. Otherwise, you can do better I think with a pair of SSD's (but you'd really want to get these off of the ICH if you do, as the ICH has a bandwidth limitation of ~660MB/s, and it doesn't scale with SSD's as it will with mechanical disks).

Either way, you're over-doing it on both areas (i.e. wasting your money).

The first thing you actually need to do in terms of scratch (to make sure 24GB is enough, but it should be), is check your efficiency in PS. If it's not 100% (or near it, as it may only show 99.9% at best), then upgrade the memory. The point behind this is, memory is far faster than scratch space, no matter if it's HDD or SSD based. It's even faster than a RAM disk, due to the bandwidth limitation of the PCIe slot it would be inserted in.

If you've sufficient memory, PS won't go to scratch that much, and actually run faster (takes advantage of the memory instead). Then the more important bottleneck to be addressed will be the primary data storage area (where ever you're placing the completed projects/files).

This is why a single SSD for OS/applications, and a separate SSD for scratch work well (it does assume there's sufficient memory in the system where scratch isn't thrashed).

You can create a stripe set for your primary project data, and make sure you've a proper backup for it, as the data will be gone when one of those disks fails. Personally, I prefer a redundant form of RAID (10 if you won't/can't go for a proper RAID card), as OS X can handle that (0/1/10 and JBOD).

RAID 5/6/50/60 will require a proper RAID card, but there's other advantages by getting one (faster performance, better recovery options, online expansion, and changing levels with redundant arrays without data loss are the major ones).

I can't stress enough how important a proper backup system is though. And a good UPS as well, particularly with RAID (can save you having to go back and re-perform lost work in the event of a power failure, and the application doesn't automatically resume).

 

[DeeEss]

oh damn it, double post again. Sorry.

 

[DeeEss]

NP.


The only reason to stripe a pair of SSD's for an OS/applications disk, is if you can get the capacity cheaper than a single disk (and you can spare the additional SATA port). That's it.

Now as an OS/applications disk is primarily read, you don't need the additional over-provisioning of the RE series either. Nor do I see a reason you need 200GB capacity, unless there's a massive amount of libraries I'm not aware of (but even if there are, you could go for the 240GB Pro series instead, and save $70USD). If you don't have such a library, then the 120GB Pro is probably overkill.

Using 4x 3TB in a stripe set for scratch is also overkill. Use smaller disks if you're going with mechanical. Otherwise, you can do better I think with a pair of SSD's (but you'd really want to get these off of the ICH if you do, as the ICH has a bandwidth limitation of ~660MB/s, and it doesn't scale with SSD's as it will with mechanical disks).

Either way, you're over-doing it on both areas (i.e. wasting your money).

The first thing you actually need to do in terms of scratch (to make sure 24GB is enough, but it should be), is check your efficiency in PS. If it's not 100% (or near it, as it may only show 99.9% at best), then upgrade the memory. The point behind this is, memory is far faster than scratch space, no matter if it's HDD or SSD based. It's even faster than a RAM disk, due to the bandwidth limitation of the PCIe slot it would be inserted in.

If you've sufficient memory, PS won't go to scratch that much, and actually run faster (takes advantage of the memory instead). Then the more important bottleneck to be addressed will be the primary data storage area (where ever you're placing the completed projects/files).

This is why a single SSD for OS/applications, and a separate SSD for scratch work well (it does assume there's sufficient memory in the system where scratch isn't thrashed).

You can create a stripe set for your primary project data, and make sure you've a proper backup for it, as the data will be gone when one of those disks fails. Personally, I prefer a redundant form of RAID (10 if you won't/can't go for a proper RAID card), as OS X can handle that (0/1/10 and JBOD).

RAID 5/6/50/60 will require a proper RAID card, but there's other advantages by getting one (faster performance, better recovery options, online expansion, and changing levels with redundant arrays without data loss are the major ones).

I can't stress enough how important a proper backup system is though. And a good UPS as well, particularly with RAID (can save you having to go back and re-perform lost work in the event of a power failure, and the application doesn't automatically resume).

Brilliant, thankyou. Great info. Actually the 12TB is for all my Data. Lightroom Library, Retouched PS files, Motion, Logic. There's quite a lot of data... My reference to scratch there was that it would be on a partition of that array, and 64gb would be enough, not the entire 12TB. But it does seem best to keep the scratch seperate then, even if I have overkilled on that one. Maybe I should use it separately as a working and scratch disk.

I have a fairly intensive backup system. Externally to another eSata Stripe and another rotated offsite. It has been working well this way for a few years now. I'm going to look into a UPS now, thanks for the info.

 

[nanofrog]

Brilliant, thankyou. Great info. Actually the 12TB is for all my Data. Lightroom Library, Retouched PS files, Motion, Logic. There's quite a lot of data... My reference to scratch there was that it would be on a partition of that array, and 64gb would be enough, not the entire 12TB. But it does seem best to keep the scratch seperate then, even if I have overkilled on that one. Maybe I should use it separately as a working and scratch disk.

I have a fairly intensive backup system. Externally to another eSata Stripe and another rotated offsite. It has been working well this way for a few years now. I'm going to look into a UPS now, thanks for the info.

Then go the following:

• 1x SSD = OS/applications (keep any libraries you have for PS and similar applications here)
• 1x SSD = Scratch (OWC's 40GB would be sufficient, and at $100USD, it's cheap enough you can replace it when it dies)
• 4x 3TB = Stripe set for project data (personally, I'd still recomend going with a level 10 configuration, but it will half the available capacity - a lot less work though if a disk dies than a stripe set would)

Make sure you're backup is sufficient, and get the UPS (make sure it has a pure sine wave inverter, not a stepped unit). Refurbished will work fine (I use them all the time), and saves a substantial amount of cash.

 

[DeeEss]

Brilliant, that looks good. Really appreciate your input.

 

[Honumaui]

not sure how much you use LR ? and working in the develop module
but the cache is the thing to get on SSD the catalogs and original files not a big deal to keep on regular HDD

so depending on how much you use LR would be the key thing if you are only doing 500 or so files a week ? might be hard to justify it ? but if you are doing a lot more might be easy to justify it

 

[DeeEss]

Hey. I shoot 3-5 times a week and each job/day has 2-3000 frames plus motion too sometimes, so each job has it's own job folder containing it's own C1/DPP/LR catalogues, RAW Files, 16bit working PSDs and CMYK/RGB finals. All that happens on the working drive which as of monday will be the SSD. It then gets moved to the data drive and backed up in a couple different places. Time Machine covers it on the SSD.

Thanks for your input on this btw it's been a good learning experience.

 

[AlexMaximus]

I thought about this one..

Hint: you need a bigger card (more ports) for guinea pig operations err.... future growth and performance.

An ARC-1880ix24 should do the trick.

Not as fancy, but a lot cheaper might be this solution here for a 2008 mac pro:

http://www.barefeats.com/hard108.html

however this raid solution tops out at 180MB / sec. because the raid chip is not able to handle more.. still a lot cheaper then 1100 bucks for the areca card...

Some german folks tested it here..

http://www.macwelt.de/artikel/_Tests/364332/test_stardom_pro_drive_pd2500/1

by the way, there has been this older article regarding Raid 0 and booting with mechanical hd's...

http://www.barefeats.com/quad08.html

 

[Transporteur]

Not as fancy, but a lot cheaper might be this solution here for a 2008 mac pro:

http://www.barefeats.com/hard108.html

however this raid solution tops out at 180MB / sec. because the raid chip is not able to handle more.. still a lot cheaper then 1100 bucks for the areca card...

That thing has nothing to do with a proper RAID card, though.
Completely different target, hence approach.

 

[Honumaui]

Hey. I shoot 3-5 times a week and each job/day has 2-3000 frames plus motion too sometimes, so each job has it's own job folder containing it's own C1/DPP/LR catalogues, RAW Files, 16bit working PSDs and CMYK/RGB finals. All that happens on the working drive which as of monday will be the SSD. It then gets moved to the data drive and backed up in a couple different places. Time Machine covers it on the SSD.

Thanks for your input on this btw it's been a good learning experience.

if you work in Develop mode in LR then putting the cache on SSD is going to be a big bump
I hate the darn lag in the white sliders !!!!! but over the last 6 months I have got mine down to almost no lag

a graphic I had from a post on another forum shows you can gain some speed with the SSD cache

notice the 3rd one down showing cache on SSD and catalog on regular HDD still about as quick as catalog on SSD also doing raid 0 did not really help ?
I did a ton more testing than this but just posted the main info

about a month later
I had added a new machine configurations etc..
so the chart below did not use the same test files as the chart above ! the chart above was on my mac 3,1

I was not as concerned about comparing the file times as I was machines in my next test comparing a 3,1 to a 5,1
so here it is a month later further tweaking LR is getting pretty darn quick for me

I was amazed at the jump in speed I got from a newer machine ?

also trying raid 0 again and more discs I went up to 3 discs and noticed each disc was .02 second gain ?

I have a post production company for pro photographers and we do mostly album design and PS work and raw conversions
I am also a commercial photographer who does some weddings
just so you know where I am coming from

my main machine is a Mac Pro 5,1 is a 4 core 3.2Ghz model with 24 gigs areca 1222x with 8 750 gig HDDs and a few other raid boxes for bu etc..
SSD are from OWC I have two of the 100 RE and three of the 40 gig regular

 

[DeeEss]

if you work in Develop mode in LR then putting the cache on SSD is going to be a big bump
I hate the darn lag in the white sliders !!!!! but over the last 6 months I have got mine down to almost no lag

a graphic I had from a post on another forum shows you can gain some speed with the SSD cache

notice the 3rd one down showing cache on SSD and catalog on regular HDD still about as quick as catalog on SSD also doing raid 0 did not really help ?
I did a ton more testing than this but just posted the main info

about a month later
I had added a new machine configurations etc..
so the chart below did not use the same test files as the chart above ! the chart above was on my mac 3,1

I was not as concerned about comparing the file times as I was machines in my next test comparing a 3,1 to a 5,1
so here it is a month later further tweaking LR is getting pretty darn quick for me

I was amazed at the jump in speed I got from a newer machine ?

also trying raid 0 again and more discs I went up to 3 discs and noticed each disc was .02 second gain ?

I have a post production company for pro photographers and we do mostly album design and PS work and raw conversions
I am also a commercial photographer who does some weddings
just so you know where I am coming from

my main machine is a Mac Pro 5,1 is a 4 core 3.2Ghz model with 24 gigs areca 1222x with 8 750 gig HDDs and a few other raid boxes for bu etc..
SSD are from OWC I have two of the 100 RE and three of the 40 gig regular

Hey Honumaui, nice setup.

This is great info, thanks. I thought just yesterday that I should have got a third drive for a 3 disk raid as I had heard this is fastest and maxes out the Mac Pro bandwidth. Well my 2 OWC RE disks should be arriving on monday with my 24Gb of RAM too so I'm going to try it out and see how it goes, maybe order another.

Are you putting your RAW files with the catalog on the SSD or just the Catalogue files/Cache on the SSD. I think the next purchase on the cards will be a Sonnet E4p, or something similar to get some fast Sata SSD happening.

I actually use Lightroom just for the editing process and quick global colour corrections etc for the client edit. All my Raws are converted in DPP for Canon and C1 for the Phase Back. But the catalogue grid is gonna scream in LR with the new machine. No more waiting for previews to render and clients tapping their fingers. It's one irritation on shoot day I have hopefully just eliminated.

 

[Honumaui]

I used to use C1 a lot
not as much these days but in the old Rob Golbraith days I did a lot to promote them so never had to pay for C1 they gave me a few lic to have

my setup is LR cache and PS scratch are on SSD
my main files and catalogs live on the areca raid which is pretty quick and secure etc..
then backup to a PM setup and TM is also on a PM setup
my boot is on SSD

all my testing showed the cache was the main thing to get on SSD and with catalogs and files being larger figured why waste the expensive space of SSD

3 SSD on the ICH throttles I had a post with numbers some months back ?

 

[DeeEss]

I used to use C1 a lot
not as much these days but in the old Rob Golbraith days I did a lot to promote them so never had to pay for C1 they gave me a few lic to have

my setup is LR cache and PS scratch are on SSD
my main files and catalogs live on the areca raid which is pretty quick and secure etc..
then backup to a PM setup and TM is also on a PM setup
my boot is on SSD

all my testing showed the cache was the main thing to get on SSD and with catalogs and files being larger figured why waste the expensive space of SSD

3 SSD on the ICH throttles I had a post with numbers some months back ?

Yes I use LR alot more now too. It's a great program and has sped up the editing and initial correction part of the job 10 fold. I just wish the tethering function worked better, it's so slow. I can imagine much better with the SSD. C1 is pretty good, for Phase One, but I get better RAW processing with Canon DPP for Canon and shooting tethered is instant, but it's a pig of a program to use. It is slowly getting better, they've finally added collections to it. Ha. Close to 10 years later!

Good testing. Well I'm going to try out my tried and true method of everything being on the SSD and then it gets moved over to the Data Disk later. It's just such a simple one folder set up that I don't need to worry about recombining later. I find LR doesn't like big catalogues, even though LR3 is better. I'll probably get a third SSD to Raid, as you have done too - Will it still get throttled with a new pci card?

 

[gugy]

Ssd raid 0 and photoshop

Hi,
I am a bit confused about RAID 0.
Most of my work is compositing large images in Photoshop. I am thinking in buying 2 SSD from OWC and make a RAID 0 because I heard it does speed things immensely in Photoshop.

My two questions are:

Do I really need to do RAID 0 or can I just have 1 SSD, maybe with larger capacity?

If RAID 0 is that beneficial, how do I set it up after I buy the two SSD drives?

I have a 12 core MacPro and I am planning to buy the multi-mount from OWC to set it up on my empty lower optical bay.

Finally, I currently have 8 gigs of RAM and how much more should I buy for Photoshop? I was thinking 12 or 16 more gigs.

I appreciate any feedback.

 

[Honumaui]

raid 0 wont speed up PS ? on its own
what will is a combination of things
your version of PS your OS your memory and of course the chip speed and scratch and storage a bit depending on the other factors

for the Mac being on SL and using CS5 is the biggest gain along with enough memory ? how much ? well that depends on your file size and such

12 gigs or 16 gigs should do it for most people
you can check PS efficiency I wrote how a few times an
then hit that little triangle to bring up info options check off scratch size and efficiency
basically you want your efficency to stay as close to %100 as you can
your scratch numbers are the left one is how much the document is taking up and the right one is how much your system has left to use

also note its the last thing done in PS for efficiency so if you have a action with 3 things it only shows the last step done not a total of all 3 !
so you want to check things as you work

also check your activity monitor for total memory used
I tend to use 4-6 gigs all the time in my system so with 24 figure I have about 18 left over for PS

so doing a little bit of work on this will help you decide how much memory you need

also a google search will turn up tons of info
in PS hit F8 or go to window>info
basically you want PS to run without going to your scratch disc
if PS hits scratch meaning it ran out of memory then having a SSD as scratch will help things out

24 gigs should give you more than enough room for files up to a gig
most of my files are 300 + megs and I never run into a memory issue
but my system while I am working in PS ends up using about 14-18 or so gigs of memory so 24 fit my work


large files over say 300 megs save as uncompressed TIFF

not sure your SSD size ?
I would run one as boot and one as scratch.cache depending on the size of them ?
if you use LR at all get the cache on SSD !!! it helps a ton just the cache not the catalog or original files

so what size are your SSD
what are your other HDDs you are going to use ?
how big are your PS files ?
how much time do you spend in PS ?
what other programs do you use a lot ?

these will help get your a bit more efficient setup

 

[gugy]

raid 0 wont speed up PS ? on its own
what will is a combination of things
your version of PS your OS your memory and of course the chip speed and scratch and storage a bit depending on the other factors

for the Mac being on SL and using CS5 is the biggest gain along with enough memory ? how much ? well that depends on your file size and such

12 gigs or 16 gigs should do it for most people
you can check PS efficiency I wrote how a few times an
then hit that little triangle to bring up info options check off scratch size and efficiency
basically you want your efficency to stay as close to %100 as you can
your scratch numbers are the left one is how much the document is taking up and the right one is how much your system has left to use

also note its the last thing done in PS for efficiency so if you have a action with 3 things it only shows the last step done not a total of all 3 !
so you want to check things as you work

also check your activity monitor for total memory used
I tend to use 4-6 gigs all the time in my system so with 24 figure I have about 18 left over for PS

so doing a little bit of work on this will help you decide how much memory you need

also a google search will turn up tons of info
in PS hit F8 or go to window>info
basically you want PS to run without going to your scratch disc
if PS hits scratch meaning it ran out of memory then having a SSD as scratch will help things out

24 gigs should give you more than enough room for files up to a gig
most of my files are 300 + megs and I never run into a memory issue
but my system while I am working in PS ends up using about 14-18 or so gigs of memory so 24 fit my work


large files over say 300 megs save as uncompressed TIFF

not sure your SSD size ?
I would run one as boot and one as scratch.cache depending on the size of them ?
if you use LR at all get the cache on SSD !!! it helps a ton just the cache not the catalog or original files

so what size are your SSD
what are your other HDDs you are going to use ?
how big are your PS files ?
how much time do you spend in PS ?
what other programs do you use a lot ?

these will help get your a bit more efficient setup

Thanks for the detailed info.
I am thinking in getting a 120gig SSD for apps/boot and a 40 or 60 gig for scratch disk.
Most of my Photoshop files are around 200 to 400 mb. The thing is I usually have open Photoshop/Illustrator/Bridge/After Effects at the same time. I usually exchange files in between these applications. add to that (safari, mail, ichat, preview and suitcase for fonts)
On top of that I have 4 more HDs on my MacPro. 1tb for my main drive, 2tb for media files, 1tb for past work archives and 2tb for Time machine.
regards

 

[mdgm]

On top of that I have 4 more HDs on my MacPro. 1tb for my main drive, 2tb for media files, 1tb for past work archives and 2tb for Time machine.
regards

Is that hdd for Time Machine backing up your Mac Pro? If you store data all on one device that may be convenient, but it's not a very good idea imo to store backups of data on the same device as the primary copy. Offsite backup of important data is crucial.

If you backup to another device for Time Machine, that frees up an extra drive bay to put in a SSD or a hard drive for some other purpose.

 

[gugy]

Is that hdd for Time Machine backing up your Mac Pro? If you store data all on one device that may be convenient, but it's not a very good idea imo to store backups of data on the same device as the primary copy. Offsite backup of important data is crucial.

If you backup to another device for Time Machine, that frees up an extra drive bay to put in a SSD or a hard drive for some other purpose.

Yes, that time machine drive back the other 3 drives on my MacPro. You are right, I am a bit lazy. I should set up another external drive for a more secure back up. Do you have a strategy for doing that? Also do you recommend any hardware for that. I would end up backing up around 3 or 4tb of files.
Thanks

 

[Honumaui]

if you use a SSD for LR cache and PS scratch a few things

40 gigs will allow you to have about 25 gigs of LR cache
if you also double use it for PS just make sure you dump your cache before PS use ! as you might fill it up ? so also in PS set a second scratch disc such as your BU disc that is not in play with working on files

so 40 will work but a big of juggling maybe
if you dont dump your LR cache not a big deal as PS will just jump to the next drive but with files that large it will jump to the next drive if it runs out of memory so just be aware of that

if you use LR as a large catalog and regularly sort your images etc..
vs using it to develop your raw files and export and move on this will also determine how much cache size you want to have and if you want to be dumping it all the time !!!

 

[DeeEss]

if you're working on big files. I think you'll find 8gb RAM is too little.

If you haven't already, you can see how much you're using now by taking a look at activity monitor. Down the bottom, click System Memory. Also check your photoshop efficiency either at the bottom of the standard window info dialogue. Or the info palette ensure it's visable in the info palette options. 100% or very near is the goal. Below 75% means there's something that needs to be looked at...

Photoshop is my main use, I work on files that are 2 or 3+gb and find that the 24GB of RAM I have is enough but I could use 32gb easily.

I have a RAID 0 array of two SSD's using it for my boot/app/working and a partition for scratch/cache. It's a really quick machine. I have a separate partition so I can quickly and easily erase it.

I also have a 4x Raid 0 HDD array which in some cases such as Sequential Uncached Write is better with speeds, at the moment, of 455.76 MB/sec compared to around 285.22 MB/sec for the SSD Raid 0.

 

[gugy]

if you use a SSD for LR cache and PS scratch a few things

40 gigs will allow you to have about 25 gigs of LR cache
if you also double use it for PS just make sure you dump your cache before PS use ! as you might fill it up ? so also in PS set a second scratch disc such as your BU disc that is not in play with working on files

so 40 will work but a big of juggling maybe
if you dont dump your LR cache not a big deal as PS will just jump to the next drive but with files that large it will jump to the next drive if it runs out of memory so just be aware of that

if you use LR as a large catalog and regularly sort your images etc..
vs using it to develop your raw files and export and move on this will also determine how much cache size you want to have and if you want to be dumping it all the time !!!

Thanks!
Sorry for my ignorance but what is LR (Lightroom?) If it is I don't use it at all. Aperture here and there, but not much.
Most of my composites are for graphic design. I don't play much with photographs.

 

[gugy]

if you're working on big files. I think you'll find 8gb RAM is too little.

If you haven't already, you can see how much you're using now by taking a look at activity monitor. Down the bottom, click System Memory. Also check your photoshop efficiency either at the bottom of the standard window info dialogue. Or the info palette ensure it's visable in the info palette options. 100% or very near is the goal. Below 75% means there's something that needs to be looked at...

Photoshop is my main use, I work on files that are 2 or 3+gb and find that the 24GB of RAM I have is enough but I could use 32gb easily.

I have a RAID 0 array of two SSD's using it for my boot/app/working and a partition for scratch/cache. It's a really quick machine. I have a separate partition so I can quickly and easily erase it.

I also have a 4x Raid 0 HDD array which in some cases such as Sequential Uncached Write is better with speeds, at the moment, of 455.76 MB/sec compared to around 285.22 MB/sec for the SSD Raid 0.

Thanks for the info!

 

[Honumaui]

Thanks!
Sorry for my ignorance but what is LR (Lightroom?) If it is I don't use it at all. Aperture here and there, but not much.
Most of my composites are for graphic design. I don't play much with photographs.

yeah sorry I think I had you mixed up with that other thread where they were asking about LR

the PS info still applies of course