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Question

Usb 3.0 as scratch disk in photoshop?

Forum|Forum|3 years ago
August 5, 2022
5 replies
11279 views

I'm trying to use a SanDisk 256gb usb 3.0 thumb drive on windows as scratch disk and it's formatted as FAT32 and Photoshop 2022 will not recognize the drive in scratch disk preferences, so should I format the thunb drive to NTFS?

Windows

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JHillPhD

Known Participant

I have a SanDisk external SSD 1TB and I have formatted it to "MacOS Journaled"but you can format it to NTFS since it's faster than the other formats. If you work between both PC and Mac then FAT32 is the way to go. Once you're done start up Photoshop then go to Preferences -- Scratch Disks and you should see your drive in the list. Click the check box and move it to the top of the list so Photoshop knows to use that drive first for the heavy lifting and make sure it's empty with no files saved on it to get the most out of it.

Chris 486

Community Expert

I would recommend formatting to NTFS for better speed. It may help the drive to be recognized as well. Are you getting any errors specifically or are you just not seeing it as an option?

Ged and Test do have a point as thumb drives can be more delicate to use. Yes, they can and will work, but also yes that they are not normally recommended for scratch disk use.

D

David Frock Nor CalAuthor

Participating Frequently

I don't see the drive as an option in preferences, it says drive c: my main hard drive and there is no drive d: which is the usb 3.0 drive that is recognized in file explorer as well as recognized when I go to file>save or save as.. in photoshop. I think I went to format the thumb drive as NTFS on my computer , which is windows 10, and it has 2 ways to format the drive , quick way does the format in under ten seconds and the slow way which looked like it would take 12 to 24 hours to format at the rate it was going and I did quick format and it doesn't show up I'm preferences so maybe if I try to format it the slow way?

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David Frock Nor CalAuthor

Participating Frequently

I know the page says no thumb drives and the photoshop preferences won't even recognize the thumb drive as drive d: like my computer will show it as drive d: so yeah thumb drives won't work and the other poster said use a ssd drive with USB 3.0 because they are built differently and so did the adobe chat agree with that

T

Test Screen Name

Legend

It may seem that an external hard drive is just the same thing as a thumb drive. But really, they are not. They just aren't made for that sort of heavy use. Without recommending it for this use, I note that Sandisk make a range of "Portable SSD".

J

John Dzwonar5FAE

Participant

this is purely misinformation. Nothing is different internally form a flash drive and an external hard drive. The only differences are physcial size and internal size. The format of a drive is the format of a drive. The vessel and sahpe that drive comes in mean literally nothign to your computer. This is simply an issue wioth the very unstable architecture of Mac OS. This dosnt happen on my PC

Conrad_C

Community Expert

this is purely misinformation. Nothing is different internally form a flash drive and an external hard drive. The only differences are physcial size and internal size. The format of a drive is the format of a drive. The vessel and sahpe that drive comes in mean literally nothign to your computer. This is simply an issue wioth the very unstable architecture of Mac OS. This dosnt happen on my PC
By @John Dzwonar5FAE

Let’s get some terms straight here.

The original post, and the post you’re replying to, are talking about a “thumb drive,” or USB stick drive. These tend to have a very low price per GB.

Your reply talks about a “flash drive,” which can be a USB thumb drive or an SSD because they both use flash memory, and you compare it to a “hard drive.” (Hard drives are currently discouraged as Photoshop scratch disks because they are too slow compared to the SSDs we have now.)

Thumb drives are not the same as real SSDs or hard drives, and that causes you to miss one extremely important difference:

The performance. This is where we have to be careful about terms.

A Photoshop scratch disk must be FAST, because it’s basically used as a RAM cache.

On any platform (Mac, PC, Linux…):

A good hard drive can achieve 150-250MB/sec.

A SATA SSD can achieve up to around 550MB/sec.

An NVMe SSD can achieve beyond 7000MB/sec.

(All of the above are subject to the limits of the protcol used to connect them, so if USB 3 is used, they will be limited to around 500 or 1000MB/sec depending on the USB port spec.)

But…

If it’s a cheap USB thumb/stick drive, the kind you can get for around $10-30, it uses cheap slow memory and controller, and usually has very slow read/write compared to a true SSD. Maybe as slow as well under 100MB/sec. In addition, it’s typical for it to start fast and then slow down for much of the rest of the transfer.

Therefore, the preferences for a Photoshop scratch disk are, from best to worst:

Internal SSD, preferably one at the highest current throughput such as over 7000MB/sec. If you have over 500GB free on an internal SSD, this is the best Photoshop scratch disk solution.
External SSD, preferably with a Thunderbolt 3 or 4 interface (40Gb/sec, or up to 3000MB/sec real world). This is expensive.
External SSD, preferably with a USB 3 interface (10Gb/sec, or up to around 950MB/sec real world). This is affordable and fast enough to be a decent Photoshop external scratch disk.
External SSD with a USB 3 interface (5Gb/sec, or up to around 550MB/sec real world). You may have to put up with this if you have an older computer.
Hard drive, up to 250MB/sec if you’re lucky.
USB flash/stick/thumb drive, read/write may vary and may be slower than a hard drive.
Floppy disk. (I said best to worst, and this is the absolute worst unless you count a cassette drive). 🙂

I benchmarked a Samsung USB flash drive I have, a current model. The Read speed is sort of OK, somewhere between a hard drive and a low-end SSD. But the 55.6MB/sec Write speed is abysmal…about the same speed as a hard drive from a quarter of a century ago, and absolutely unacceptable for a Photoshop scratch disk. What I actually use for a Photoshop scratch disk is a true SSD in an external USB 3 10Gb/sec enclosure. Both are in the picture below.

So even if Adobe allowed USB stick/thumb/flash drives to be assigned as Photoshop scratch disks, that would be a very bad idea in terms of speed. Use a real SSD. The latest NVMe external SSD enclosures are almost as small as a thumb drive, but are much faster than a thumb drive, and can cost under $100 now.