Semi-quantitative analysis of file transfer speeds with Macs

[paintingwithlight]

Good day all,

I've always hated having to wait while my photos (raw, 24 MP) transfer from my SD card into Lightroom (on an iMac, circa 2013). I also dislike having to wait for an image to load (in Lightroom) when moving from one photo to another. I recently bought a new MacBook Air with SSD. Unsurprisingly, with the SSD the amount of time I have to wait for photos to load when moving from one image to the next in LR has approached zero. I've noted that file transfers from the SDHC to the SSD is about 4 times faster than file transfers to a non-SSD hard drive. I've also noted that file transfers between using Apple's (wireless) Air Drop is approximately 8 times faster than first writing the files to an SDHC card on one computer then reading them into another. Below is a semi-qualitative analysis of time savings that can be realized if you use a laptop on the road with an SSD and later transfer the files to a laptop (without SSD) using Air Drop:

1. Assumptions: you edit the files on the road keeping 100% of the images and want to transfer them all off the laptop to your desktop. Transfer time using the laptop first is 1/4 (fractional time saving reading into laptop) + (1/8 (fractional time saving transferring files with Air Drop)) x 100% (percent of photos that you are transferring to laptop) = 3/8 or 37.5%. Put another way, the transfer speed ratio improves by 2.7:1 in mediating the file transfer via a laptop with SSD.

2. Assumptions: you edit the files on the road keeping 30% of the images and want to transfer that 30% off the laptop to your desktop. 1/4 (fractional time saving reading into laptop) + (1/8 (fractional time saving transferring files with Air Drop)) x 30% (percent of photos that you are transferring to laptop) = 28.8%.
The transfer speed ratio improves by 3.5:1 in pre-editing files on a laptop (culling the photos by 70%) and mediating the file transfer via a laptop with SSD.

FYI.

-michael

[Dave Humphries]

Interesting Michael,

I recently moved to an SSD PC and didn't see much of an improvement in my transfer speed, but in reading your process, I realise what probably caused this

I had set it up to parallel import to the primary SSD location (for editing) and a backup location - which is a traditional spinning platter drive - so obviously it can only import dependent upon the speed of the slowest device

Next time I'll try to just the SSD and see what I get.
(then later backup the files to HDD)

So thanks for my 'penny drop' moment

Cheers, Dave

[John 2]

My system drive is an SSD but I keep my DATA on a separate internal standard hard drive. Although the time for the computer to boot up is very much reduced using an SSD and keeping it relatively uncluttered, as Dave indicates, image transfer times are governed by the speed of my Data drive. Large capacity SSD's are still too expensive a proposition to justify there use for the Data drive for the number of images I store. (I really must do some house keeping). Two things that I have noticed however, are that my image transfer speed from SDHC cards has been hugely improved by using a USB 3 card reader. Several per second despite the fact that the Fuji produces 48MB files. Secondly, using the same computer, after I installed W10 and PS CC, the start up time for Photoshop in particular, is quite slow. Don't know why this should be given that my apps are all on the SSD.

[Dave Humphries]

Two things that I have noticed however, are that my image transfer speed from SDHC cards has been hugely improved by using a USB 3 card reader. Several per second despite the fact that the Fuji produces 48MB files.

My first (only) download was with the built in SD card reader, the spec for the PC is vague - it implies it is connected via USB3 header, but I'm not so sure, since I didn't see the improvement John has. I have since bought a separate USB3 reader, but I haven't had an opportunity to use it yet. (Must shoot more!)

Secondly, using the same computer, after I installed W10 and PS CC, the start up time for Photoshop in particular, is quite slow. Don't know why this should be given that my apps are all on the SSD.

Can you not work (edit) from the SSD in your 'active' folders (i.e. most recent 2-3 downloads), to gain the speed advantage, then move the files off to the 'Data' HDD? (that's my intended practice)

I suspect it is because you have PS CC set up to use the HDD as the data drive, including it's scratchpad, that is causing the slow opening. Mine flies open now - well, I guess it's about 10-15 secs instead of 1.5 minutes!

Cheers, Dave

[John 2]

..........I suspect it is because you have PS CC set up to use the HDD as the data drive, including it's scratchpad, that is causing the slow opening. Mine flies open now - well, I guess it's about 10-15 secs instead of 1.5 minutes!

Cheers, Dave

That gave me a thought Dave. I think that you're right. I normally open Photoshop via Bridge which by definition, means I'm transferring an image. Opening Photo Shop from the App list i.e. without an image file in place, is definitely quicker but never the less, not as instantaneous as it used to be in W7. I can live with it though. My comment was only an observation.

[paintingwithlight]

I had set it up to parallel import to the primary SSD location (for editing) and a backup location - which is a traditional spinning platter drive - so obviously it can only import dependent upon the speed of the slowest device

...

So thanks for my 'penny drop' moment

Cheers, Dave

Hi Dave and John,

Thanks for your replies. I created this post to try to vaguely quantify speed increases so that others can decide whether SSDs, with their higher cost and lower capacity, are worth it.

To compare two different methods:

1) SDHC -> SSD (notebook) -> traditional HD (desktop) via AirDrop (the AirDrop files end up in Downloads and have to be imported into LightRoom but that transfer is trivially quick since the file are already on your hard drive); and

2) SDHC -> traditional HD (desktop) via SDHC slot on iMac.

Method 1, which involves an extra step and wireless transmission, is much faster. I found this surprising. Thought I'd share.

The increased transfer speed is one benefit of SSD. The other is the speed of loading images. I often take 3+ images of a scene and page back and forth to see which I prefer. With the SSD the images appear to load in a fraction of a second which is great.

My next test will be to see if there is an increase in speed (with SSD) when creating a panoramic image in Lightroom - if I try to stitch 4 or more images together the process leaves me with enough time for a quick cup of tea. I suspect that in this case there may be more factors at play such as CPU speed and RAM but we'll see.

Cheers,

Michael

[rpcrowe]

Although I have an SD slot in my Canon 7D2 DSLR, I shoot CD cards exclusively. Using Lexar cars from 300x up to 800x with UDMA and UDMA 7 (on the 32 Gig 800x CF cards) my transfer is, IMO, exceptionally fast. I usually open anywhere from 30 images (of a dog shoot) to several hundred images (travel or event shoot) and I am really impressed at how fast the images open and are copied to my hard-drive and back-up disk.

I use an SSD for my program disk and store my images on a standard hard-drive as well as an external Western Digital hard drive as initial back up. I have noticed in extremely unscientific testing, that the speed of my CF card as well as whether the card has UDMA technology, is the biggest factor in determining the speed of download from the disk.

I originally used UDMA CF cards before I had a camera that was UDMA capable. If I used a 300x UDMA CF card in my 30D and 40D cameras, there seemed as if there was no discernible difference in the write speed to the camera. However, using a UDMA capable Lexar card reader, there was certainly a noticeable difference in opening the files - even though I was using an old and slow (for today's standards) laptop computer. I began to notice a difference in speeds after I was shooting with my 7D cameras which were capable of utilizing the card's UDMA. Now with the relatively larger files of the 7D2, there is a real difference.

BTW: My standard workflow is now to open my files using Adobe Bridge and Adobe Camera RAW using a Lexar UDMA capable card reader with USB 3.0. I have not been on any trips lately, so I have been opening the files using my Dell Desktop computer which has an SSD plus a standard hard-drive as well as tons of RAM.

If I do go on a trip in which I would plan to shoot loads of images, I would need to decide on whether I wanted a new laptop or whether I was willing to use the old model. That would probably depend on how thick my wallet felt at the time...

[paintingwithlight]

My next test will be to see if there is an increase in speed (with SSD) when creating a panoramic image in Lightroom - if I try to stitch 4 or more images together the process leaves me with enough time for a quick cup of tea. I suspect that in this case there may be more factors at play such as CPU speed and RAM but we'll see.

I did the test. There was a slight improvement in speed in stitching together a panoramic photo in LR6 using a laptop with SSD but the increase in speed (about 10-20%) was so small that I can't unambiguously ascribe it to the SSD as the two computers have different CPU speeds and RAM. A non-result.