A

Anonymous

Question

Scratch Disk For Photoshop?

Forum|Forum|6 years ago
August 8, 2019
6 replies
5059 views

What are the advantages to having a scratch disk on an SSD for your workflow? Do you guys ever come across a situation where you found you were bottle-necked by the RAM capacity in your workflow?

scratch disk

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JJMack

Community Expert

Anything the reduces latency will help performance how much it improve performance at what cost enter is more a value issue. Justerforcation may depent on the type of work one dose. If one is dealing with giga pixels image with many layer any improvement in performabce may be preceived by the user and may justify the cost. If you deal with small image and files you may precieve no improvement in performance for the computer is for the most part waiting on you to give it work to do when you are manually using Photoshop UI.

JJMack

Community Expert

Only Adobe has access to Photoshop code and design. We are uses id Adobe Software. All we can tell you for sure is Photoshop is a resource hungry application. And the way you configurable it can cause it toe be very hungry. Some things are very expensive like History states. If you keep hundreds for open documents Photoshop will need to use more RAM and scratch space. Opening smart object and Photoshop will use temp space. Only some features make use of your GPU. So how you use Photoshop greatly influences Photoshop's operation. There is not a single Photoshop workflow.

Use some system monitor and observe what is going on when you use Photoshop.

JJMack

D Fosse

Community Expert

The scratch disk is the single most important component in the entire Photoshop ecosystem.

Everything in Photoshop is written to the scratch disk, as far back as your history states go. That's the main memory.

RAM is a fast access cache to the scratch disk. It used to be very important because disks were slow. Now, with the ridiculously fast NVMe drives, that's no longer a practical consideration and there's little reason to have excessive amounts of RAM.

The general advice today, for best performance, is to have the scratch disk on the system drive (NMVe SSD). A separate scratch drive is no longer advised (as it was with spinning drives).

JJMack

Community Expert

You need to be careful. Your system will not run well if you system Disk(or SSD) files up. For good performance there need to be free space on your system disk. I have seem Photoshop use over 120GB of scratch disk space on my machine. Mobile machine like windows laptops will usually have hibernate enabled. That allocated at least a RAM size chunk of space on your system disk. Free space on your system disk may be to small to use as Photoshop first scratch disk. Photoshop may fill your system disk in no time. I disable hibernate on my workstation to recoup 40GB of free space on my system SSD it only a 256GB SSD. Windows and Adobe software eat around 70GB of space on that SSD.

JJMack

A

Anonymous

Thank you for your reply.

One more question. Do you think there's a significant advantage in workflow if you were connecting your SSDs via an NVMe interface as oppose to something like SAS or SATA? I speculate that large volumes of data would require the type of speed and bandwidth provided by NVMe.

Trevor.Dennis

Community Expert

AlanLovesComputers wrote
What are the advantages to having a scratch disk on an SSD for your workflow? Do you guys ever come across a situation where you found you were bottle-necked by the RAM capacity in your workflow?

What sort of work do you do? From my experience, if you get int complex projects with lots of layer, lots of Smart Objects (Especially if you use nested Smart Objects) and I have a sneaky suspicion that if those Smart Objects contain vector layers, you want to do the very best you can regarding a Scratch disk.

To give you some perspective I currently run a i9-7900X with 64Gb of the best memory I could find, and an RTX2070. Both the boot and scratch drives are Samsung 512Gb 960PRO NVMe drives. This is the sort of performance they deliver:

I can still get bogged down with substantial temporary Photoshop files on the scratch drive, and noticeable lag. It's not terrible, but even with the performance shown above, picking out the bits it needs from a 10Gb temp file is going to take a second or two.

So do use an SSD or NVMe drive for Scratch space. You don't need to dedicate an SSD entirely to scratch space, but make sure it has plenty of space, and keep your data and program files on a different drive.

For real world best choice hardware for all types of content creation, check out Puget Systems

https://www.pugetsystems.com/all_articles.php

JJMack

Community Expert

When you open a Smart Object Layer's Object Photoshop creates a temp Work Documents in users system temp space. Those files persist till you close the document with the smart object out of Photoshop. The temp work file are not in Photoshop scratch space. On a windows system the would be in "C:\Users\(your User ID)\AppData\Local\Temp\" Which is normally on your boot disk. You can change your environment though your system variables.

JJMack

Ussnorway7605025

Legend

The main advantage of a scratch disc is that Photoshop will work if you have one... I would not recommend putting it on the SSD unless that is the only option i.e if your system includes a spinning rust then that is where you are best to place the scratch

Ussnorway7605025

Legend

when you import a image from some out side source {Lightroom, the internet etc} Photoshop puts it in the temp folder

when you open any verson of a PSD Photoshop unpacks it to ram which {by design} goes to scratch folder first then system ram during previews... its common for new users to make big files that their system can't re-open because they lack the scratch | ram to do so

Photoshop is designed to work on Mac systems so Cpu is what does 90% of the work... only some 3d | video & preview options use the Gpu

Trevor.Dennis

Community Expert

The short answer is, if you can fit everything you need on an NVMe SSD, then go ahead do that, and you're done.

But NVMe is the most expensive type of storage, and the maximum available size is not that big compared to hard drives. Professional users editing TV series or feature films at 4K and higher have tens or maybe hundreds of terabytes of video to work with. There are no single NVMe drives that big. And if you find one, it probably won't fit your budget. So multiple drives are typically required, and for budget reasons not all of them will be NVMe.

The cost and relatively small maximum size of NVMe storage means productions have to prioritize what goes on the expensive fast drives. The storage used to augment RAM need to be as close to the speed of RAM as possible (that is, as fast as possible), so those are assigned to NVMe, such as media cache, rendered video previews, and maybe Photoshop scratch. Far cheaper SATA SSDs can be fast enough for other storage needs, such as audio and photos. Source clips go on whichever drive is fast enough to handle its data rate. Hard drives could be used for project files and motion graphics templates because those are so small that not much data is involved, but these days SATA SSDs are affordable enough for most.

That's why many pro video and audio applications have multiple settings for scratch drives. Because multiple drives are often required to store the sheer volume of data, you get to assign which types of media go on which drives. NVMe partitioning of a single drive would not apply, since it only handles that single drive and we're not partitioning it since there's no advantage to it.

https://forums.adobe.com/people/Conrad+C wrote
[snip]
That's why many pro video and audio applications have multiple settings for scratch drives. Because multiple drives are often required to store the sheer volume of data, you get to assign which types of media go on which drives.

With desktop towers and similar, it is such a trivial thing to add drives, you can bump your expensive NVMe drives to new systems, or through hardware updates, and use them according to priority. As I said back up the thread, I have two 512Gb 960Pro drives, but I also another two SSD drives along with a bunch of good quality HDDs for backup and non essential data. I have a third M.2 socket unoccupied 18 months after I got my current 7900X system, but I don't feel the need to invest in a third NVMe drive. I still have that option open to me though.

This approach makes reinstalling your operating system, or major hardware updates so much easier, and a lot safer from a lost data point of view.

We also have some very fast interface options nowadays. USB 3.1 (1250MB/s) does not compare with an M.2 interface, but it is fast enough to be useful.

JJMack

Community Expert

Photoshop Always use scratch space so you would want writing and reading it to be as the best performance possible to reduce latency. SSD will outperform your brown and round disk. If Find most Of the time I that Photoshop it will use around 10GB of Rams where it will use many times that amount of Scratch space. Temp space is also better on SSD than Disk Photoshop also uses temp space for work file when you do things like open smart objects. Disk Performance can vary depending on devices, system configuration and caching and fragmentation.

JJMack

A

Anonymous

Could you please explain the actual workflow of (Photoshop, RAM, Scratch DIsk, CPU, GPU, etc)? I would like to know specifically how the data is moved around in the workflow to the scratch disk and out.

Thank you so much.

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