Is it worth having two SSD for Lightroom catalouge/cache files?

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SSD drives are vastly faster than HDD drives, and many people put their programs and OS onto a modern machine build. Is there any benefit in terms of speed/wear and tear in having two SSD drives; so that the OS drive has Lightroom on it, and the second SSD drives has catalouge/scratch disks on it.

Is there any benefit doing two SSD drives, one solely for cache/catalouge, or is it just better to have everything stored on the OS SSD?

[ricktas]

SSD drives are designed to be written once read many (WORM Drive). They will fail faster if you are constantly writing to/deleting things off them. Each sector of an SSD drive has a limited amount of times it can be written to, but in theory should be readable forever.

So you SSD should be for your operating system and programmes, that once installed are just read into memory for use. All your 'working files' etc should be on a regular HDD.

[wideangle]

SSD drives are designed to be written once read many (WORM Drive). They will fail faster if you are constantly writing to/deleting things off them. Each sector of an SSD drive has a limited amount of times it can be written to, but in theory should be readable forever.

So you SSD should be for your operating system and programmes, that once installed are just read into memory for use. All your 'working files' etc should be on a regular HDD.

My question was is it worthwhile having two SSD drives to separate the program from the catalouge/cache files. I am not sure if it's worthwhile in terms of performance/wear and tear to have two or just put everything on the OS SSD. Working files would be on a traditional external HDD due to size of image collection.

[ricktas]

you also asked "is it just better to have everything stored on the OS SSD?" which I answered. The answer is NO. Do NOT use SSD drives for cache or for any files that are changed frequently! You should also not defragment an SSD drive

[MrQ]

+1 to what Rick has said. You may get a small performance gain by using a second SSD but it won't be as much as you get from putting your operating system and applications on the first one. It's also not worth the increased chance of data corruption from overuse of the SSD.

You can get hybrid drives which might be worth trying for this kind of purpose though. They're basically a normal hard drive with an SSD buffer. The hard drive works out what files you're accessing frequently and moves them to the SSD part, but keeps everything safe and reliable (at least, that's the idea). :)

[MissionMan]

Technically, there would be very little benefit although it would exist. Most SATA's run at 300MB/s per device and your catalogue will not have full size images after the generation of previews so any performance gain would be minimal. My Lightroom catalogue is 400MB (40,000 images) and my previews are 5.8GB but you have to remember that although the previews are 5.8GB, it won't access all previews simultaneously, it loads them as they are needed.

I personally don't have issues with using my SSD for OS and Library, but I replace my machine every year so my risk is mitigated substantially (not sure if Windows has this in later versions but Mac's have a migration assistant that allows you to plug together two machines and it will migrate everything to the new machine so it looks like your old, complete with software activations, emails, web history and passwords). I generally have a 512GB SSD. All my gear has a 3-5 year warranty and I backup consistently every couple of minutes while I am using it. I have backups at work and at home along with cloud backups of all my data. I have a clone of my drive that is done weekly so I can plug it an external, boot directly from the clone and restore it to it's original state from the incremental backup in less than half an hour while I swap out the SSD. When the SSD returns, I can have it back in my machine and up and running with only time lost for the physical removal and insertion of the new SSD because I'll restore it in the background while I continue working. Total failure time impact for me would be under 2 hours. If I compare that to the time wasted waiting for spindle drives, I reckon I'm gaining a lot of productivity.

I've had SSD failures previously but my last SSD failure was years ago when SSD's were in their infancy (Gskill Falcon). These days, SSD's are more reliable but still less reliable than the spindle counterparts. Given the amount of time gained from using SSD's, the risk of failure is something I'm prepared to accept for the advantage of the performance gains. I still do keep my backups on spindle but that's largely because I need my backups to last longer than my machine because they don't get replaced on the same cycle.

[wideangle]

you also asked "is it just better to have everything stored on the OS SSD?" which I answered. The answer is NO. Do NOT use SSD drives for cache or for any files that are changed frequently! You should also not defragment an SSD drive

So do you just have your programs on an SSD rick, and everything else - cache/catalouge/scratch disk on a traditional HDD?

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Technically, there would be very little benefit although it would exist. Most SATA's run at 300MB/s per device and your catalogue will not have full size images after the generation of previews so any performance gain would be minimal. My Lightroom catalogue is 400MB (40,000 images) and my previews are 5.8GB but you have to remember that although the previews are 5.8GB, it won't access all previews simultaneously, it loads them as they are needed.

I personally don't have issues with using my SSD for OS and Library, but I replace my machine every year so my risk is mitigated substantially (not sure if Windows has this in later versions but Mac's have a migration assistant that allows you to plug together two machines and it will migrate everything to the new machine so it looks like your old, complete with software activations, emails, web history and passwords). I generally have a 512GB SSD. All my gear has a 3-5 year warranty and I backup consistently every couple of minutes while I am using it. I have backups at work and at home along with cloud backups of all my data. I have a clone of my drive that is done weekly so I can plug it an external, boot directly from the clone and restore it to it's original state from the incremental backup in less than half an hour while I swap out the SSD. When the SSD returns, I can have it back in my machine and up and running with only time lost for the physical removal and insertion of the new SSD because I'll restore it in the background while I continue working. Total failure time impact for me would be under 2 hours. If I compare that to the time wasted waiting for spindle drives, I reckon I'm gaining a lot of productivity.

I've had SSD failures previously but my last SSD failure was years ago when SSD's were in their infancy (Gskill Falcon). These days, SSD's are more reliable but still less reliable than the spindle counterparts. Given the amount of time gained from using SSD's, the risk of failure is something I'm prepared to accept for the advantage of the performance gains. I still do keep my backups on spindle but that's largely because I need my backups to last longer than my machine because they don't get replaced on the same cycle.

Thanks for your reply. If there is little benefit then there wouldn't be a lot of speed loss by putting catalouge/cache and photoshop scratch disk onto a secondary HDD, rather than a secondary SSD then. Doing it this way I guess would extend the lifespan of the SSD as it would only be opening/closing programs and running the OS.

[MissionMan]

Thanks for your reply. If there is little benefit then there wouldn't be a lot of speed loss by putting catalouge/cache and photoshop scratch disk onto a secondary HDD, rather than a secondary SSD then. Doing it this way I guess would extend the lifespan of the SSD as it would only be opening/closing programs and running the OS.

That's where I'd disagree. Having two separate SSD's and having an SSD and a separate HDD are two completely different things.

For one, once Lightroom is open (initially from the SSD in both scenarios), it's not having to retrieve data because both the application and library can be loaded into memory (RAM). The only performance gain of having two SSD's is that the application and library would open slightly faster on first load. I.e. you have 1GB for the application and 500MB for the library so if they are loaded in parallel at an SSD speed of 500MB/s it would take 2 seconds to open (purely based on data transfer rates and without factoring RAM, Processor etc) because both the library and application load in parallels. If you had them both on the same drive, it would take 3 seconds because all of the data has to come through a single drive and interface. Once those two applications are open, it's only the preview data that is being loaded which is unlikely to exceed the 500MB/s of the drive so the moment the library and application load, your performance gains are lost. I.e. how many photo previews would you view in a second?

Now, when we look at storing the library and previews on a spindle drive, this all changes because spindle is substantially slower. Speeds range from 70MB/s through to 300MB/s depending on the drive (2.5 vs 3.5, how fragmented the data is, does it have to spin up etc) so while the application may load quickly (2 seconds), the library could take much longer to load, and the previews could take even longer to load because they could well be stored on different areas of the drive.

Now, what do you do more often? Open the application (you do this once when you start processing) and then you work on the library, so performance while you are working is likely to be a higher priority, because even if you lose time when you first load the library, it's only a couple of second when you first open it.

Feel free to disagree with me, but that's the way I see it.

[wideangle]

That's where I'd disagree. Having two separate SSD's and having an SSD and a separate HDD are two completely different things.

For one, once Lightroom is open (initially from the SSD in both scenarios), it's not having to retrieve data because both the application and library can be loaded into memory (RAM). The only performance gain of having two SSD's is that the application and library would open slightly faster on first load. I.e. you have 1GB for the application and 500MB for the library so if they are loaded in parallel at an SSD speed of 500MB/s it would take 2 seconds to open (purely based on data transfer rates and without factoring RAM, Processor etc) because both the library and application load in parallels. If you had them both on the same drive, it would take 3 seconds because all of the data has to come through a single drive and interface. Once those two applications are open, it's only the preview data that is being loaded which is unlikely to exceed the 500MB/s of the drive so the moment the library and application load, your performance gains are lost. I.e. how many photo previews would you view in a second?

Now, when we look at storing the library and previews on a spindle drive, this all changes because spindle is substantially slower. Speeds range from 70MB/s through to 300MB/s depending on the drive (2.5 vs 3.5, how fragmented the data is, does it have to spin up etc) so while the application may load quickly (2 seconds), the library could take much longer to load, and the previews could take even longer to load because they could well be stored on different areas of the drive.

Now, what do you do more often? Open the application (you do this once when you start processing) and then you work on the library, so performance while you are working is likely to be a higher priority, because even if you lose time when you first load the library, it's only a couple of second when you first open it.

Feel free to disagree with me, but that's the way I see it.

I can see where you are coming from. From what I understand you are of the idea that having 2 SSD drives is the most effective way to go? Whilst SSD drives have limited read/write capabilities, the speed factor outweighs the loss of an SSD from overwrites etc.

[MissionMan]

I can see where you are coming from. From what I understand you are of the idea that having 2 SSD drives is the most effective way to go? Whilst SSD drives have limited read/write capabilities, the speed factor outweighs the loss of an SSD from overwrites etc.

Optimal for speed, yes, cost effective probably no. If you want the best of both worlds, I'd do the following (which is what I do):

Put your OS, Lightroom Library and Previews on a single SSD. When you first upload photos to your machine, it's likely you'll do most of your post processing in the first month or two so have Lightroom default the storage to your SSD (the actual RAW Files) and do your post processing while they are on SSD. Every month, move the old master photos you are finished with to your second drive which is on spindle. The previews are still on your SSD so viewing the library won't be slow, it's only the editing of old photos that have already been moved to the spindle drive that will be slower.

If you're concerned with the failure rate, invest in a backup solution (you should have some sort of backup anyway) that does ongoing backups as the data changes on your SSD and the Spindle (I mentioned both because often people forget to check if their backup software is backing up both drives). If you need a video of what I mean, I can load a screen cam tomorrow.

[wideangle]

Optimal for speed, yes, cost effective probably no. If you want the best of both worlds, I'd do the following (which is what I do):

Put your OS, Lightroom Library and Previews on a single SSD. When you first upload photos to your machine, it's likely you'll do most of your post processing in the first month or two so have Lightroom default the storage to your SSD (the actual RAW Files) and do your post processing while they are on SSD. Every month, move the old master photos you are finished with to your second drive which is on spindle. The previews are still on your SSD so viewing the library won't be slow, it's only the editing of old photos that have already been moved to the spindle drive that will be slower.

If you're concerned with the failure rate, invest in a backup solution (you should have some sort of backup anyway) that does ongoing backups as the data changes on your SSD and the Spindle (I mentioned both because often people forget to check if their backup software is backing up both drives). If you need a video of what I mean, I can load a screen cam tomorrow.

Cool thanks for your input. Sounds like a single SSD drive is the way to go, I also like your workflow method. Would be great to have a video of what you mean if you are able. Do you also store scratch disks on an SSD as well?

It sounds like that the only "risk" is the failure of using a single SSD, but as you say, having a backup plan will void this, simply having to replace a faulty SSD with a new one. Seems like spending a few hundred dollars based on your findings only increases speed very little. Do you have cache on the SSD too?

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you also asked "is it just better to have everything stored on the OS SSD?" which I answered. The answer is NO. Do NOT use SSD drives for cache or for any files that are changed frequently! You should also not defragment an SSD drive

Sorry Rick, I should clarify, when I said "is it just better to have everything stored on the OS SSD" I just meant cache/catalouge/scratch disks. I would be using a separate HDD for the actual image files.

[wideangle]

you also asked "is it just better to have everything stored on the OS SSD?" which I answered. The answer is NO. Do NOT use SSD drives for cache or for any files that are changed frequently! You should also not defragment an SSD drive

So where do you store your data/cache then, all on traditional hard drives? It seems to defeat the purpose of using a fast SSD drive, when the drive fails just replace it.