Everything you Wanted to Know about Digital Camera Cards, but Where Afraid to Ask

Digital camera cards and their readers are one of the things that we think we know about, but probably don’t. Since they are simple devices most of us assume that is the end of the story and don’t ask for advice or help. So without having to ask, I’m here to help de-mystify memory cards, card readers and computers.

This article is intended to help you learn about the speed of cards, readers and computers and how that effects your import time. This is an important bit of information to help you speed up your workflow. If you are behind the times and or using mis-matched gear you could be losing valuable time importing your images.

This isn’t hard, I just plug my camera in to my computer and off I go!

Connecting your camera directly to the computer is not recommended…ever! It is likely a slow connection and there is a (remote) possibility you can do damage to the camera. Your camera is really a computer disguised as a camera and so it can pick up bad information (read that as a virus) from your computer. It is also possible that your computer could make your card unreadable by your camera. This is a best practices type of thing, as I said it is a remote chance, but why would ever want to risk that.

 My card says 1000X speed it must be fast! Right?

Yes and no! IF you have a camera that can write that fast AND you have a card reader that can write that fast AND your computer has a high speed port to connect to that fast, then yes, you’re as fast as it gets. If you answered no to any of the above, you may in fact be slow!

My card says “high speed” it must be fast, they wouldn’t try to trick me would they?

Well, yes in fact they do try to trick you. I should say that they manipulate the standards. You see even a card labeled as “Class 10” which is the fastest rating for SD (that’s the really small stamp sized ones) cards are not all the same speed. There can be 50% difference in the max write speed of the class 10 cards.

Read the specification for write speed (not the marketing words), it is always true.

I just splurged and spent $70 for a new card fortunately; I saved a bunch and bought a 24 in 1 reader for $12 online. I am quite the shopper!

Perhaps you are for the prices, but you likely just bought a card that won’t match the speed of the cards you just bought. Secondly, do you really have 24 different kinds of cards? I hope not…

Just like in the previous question all card readers have specs that will tell you what their maximum read and write speeds are. A 30mbs (30 megabits per second) card becomes a 10mbs card when you try to read it with a reader that is not capable of reading 30mbs.

WOW, Ok, I junked the card reader and bought one that matches my high-speed cards. Your advice isn’t very good though, it still seems very slow. What gives?

You are most likely 2/3s of the way home. You still have one more data pipe to master and that is your connection to your computer. If your computer is 2 or 3yrs old that USB connector that you are using is likely USB 2 and it is slower than your new fast card reader. The USB standard is backwards and forwards compatible  with each other, except for speed. That means a USB 2 device will talk to a USB 3 device, but only at the USB 2 speeds.

You’ll need a USB 3 input on your computer to get the most speed during the download. You can buy a USB card for your desktop computer and you may be able to upgrade your laptop as well. It is different for almost every manufacturer, so I can’t include a list here. Your local store can help answer this for you.

I have the fastest card and yet my camera stops taking pictures while it writes to the card.

Just like with card readers, your camera can be a bottleneck. Cameras that are even 2 yrs old cannot write as fast as the cards you can buy today. Some of the very high-end DSLRs have their own internal memory (buffer) that compensates, so it may not be noticeable, but your average point and shoot will not benefit from super fast cards in this respect.

I’m using the built in reader from my computer, am I fast?

Depending on your computer, yes you can be quite fast. The Apple MacBook Pro can read faster than many readers. However, it can only read SD cards and not the larger compact flash cards common to most DSLRs.

You’ll have to read and likely dig for the specs, but since most of these are connected directly (Bus Linked) to the brains of the computer they can be very fast.

If you have an expansion slot on your laptop, there are companies like Delkin, that make excellent readers that utilize that slot and it’s Bus link to the computer.


So to summarize, you need to make sure all of your components match up. There is no need to buy a super fast card if your computer cannot read it that fast and vice versa buying a slow card for a fast computer will really slooooow down your workflow.

It is however perfectly fine and advisable to buy cards that are faster than your camera, IF you have the computer and reader that can handle it. For me this is the key combination. I can live with how fast my camera writes to the card, but if I can reduce the time to download my cards from 60 minutes to 6, I want that!

There is a fantastic website that does real world analysis of all things to do with memory cards. They actually test cards in cameras and provide real world data of how fast cards are in cameras. It is scientific unbiased information. Sadly, just this month he announced he would be discontinuing the site for the foreseeable future. It is still a treasure of valuable information and useful reading if you are really looking for speed.  It is Rob Galbraith’s DPI and you can find it here,  www.robgalbraith.com and look for the link to CF/SD/XQD on the left side of the page.

Buying Recommendations

In my experience and that of every photographer that I’ve talked to Lexar and San Disc are the 2 leaders in technology and performance. Delkin also makes a good product and some of their readers are also quite good.

In doing some research for this, I found it was really quite hard to find the max and the minimum read/write speeds for the cards and readers. This was especially true of the less expensive product. Typically, the manufacturer’s site was most helpful.

I think the best plan is just don’t be complacent. In other words, you are unlikely to be getting the best performance from anything that is over 2 yrs old. If you change a component of your workflow, like buying a new computer, don’t forget to upgrade your readers and or cards.

Next time we will talk about the import process itself and how that can affect your workflow.

Have a question that you’d like answered? Leave a comment and we’ll write about it.

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