Photography / Buying Guide

The Fastest Memory Cards Money Can Buy

Nobody has ever complained about a memory card being too fast and, increasingly, electronics manufacturers expect you to have high-speed memory cards to enable certain features. Smartphones, tablets, and even laptops often rely on memory cards for external storage these days. And, with consumers demanding both higher resolution and less compressed video from cameras, manufacturers have responded by supplying more and more capable memory cards. Today, cameras are recording 4K video to microSD cards and RAW HD video to SD cards. Luckily, memory cards have kept up with the rising demand, and the fastest cards around rival SSD drives, though finding out which ones are truly fast can be a challenge.

How to Determine Whether a Card is Fast, and the Dreaded “Up To”

When memory cards list their read and write speeds, they often use terms like “up to” or “maximum” when referring to the spec. A maximum read speed or speed “up to” a certain amount is the maximum burst speed of a card. It might be able to sustain that speed for a few seconds, which is great for quickly saving a picture, but don’t actually expect to see read and write speeds like that for sustained transfers, like shooting video. Plus, some manufacturers are a bit more liberal with the speeds they quote than others. Sustained transfer speeds can vary greatly from card to card, so to determine a memory card's overall speed by just looking at the card's advertised maximum speed isn’t always the best method.

Luckily, memory cards have a number of metrics to help you sort out which ones are fast all around, though, to the uninitiated they can be a bit overwhelming and look like random numbers. In this article we will not only tell you what the fastest cards are, but also help you understand why.

SD and microSD Cards: SD vs. SDHC vs. SDXC

One of the more obvious metrics we use when comparing SD cards has to do with whether they are SD, SDHC, or SDXC cards. While all these cards look same, the file format they use is different, which determines the maximum capacity of the card. Plain SD cards have a maximum capacity of 2GB, while SDHC cards max out at 32GB; SDXC cards can support up to 2TB—though we aren’t there yet. This metric does not affect speed at all; an SDHC card can be just as fast as a SDXC card, and oftentimes they are.

UHS (Ultra High Speed) Card Classifications

Some SD cards have UHS (Ultra High Speed) Classifications. A UHS (Ultra High Speed) Classification determines the maximum speed at which a memory card can read. This doesn’t affect the speed of the memory in the card, but manufacturers will rarely make a UHS-I card that is unable to read or write faster than a non-UHS card can. Non-UHS SD cards max out at 25 MB/s, but UHS cards can be much faster. Currently, there are two types of UHS classifications: UHS-I Cards, which have a maximum theoretical speed of 104 MB/s, and UHS-II Cards that allow for a maximum transfer speed of 312 MB/s. UHS-II cards also have a second row of electrical contacts to aid in the speed boost. If your memory card reader or camera does not have the second row of contacts, the speed will be more in line with UHS-I cards. A card’s UHS classification is a good way to help gauge its burst speeds.

Speed Class Ratings

Since card manufacturers almost always only give you burst read and write speeds instead of sustained speeds, it can be difficult to pick out a card for video. Many new 4K-capable cameras write at very high bitrates, and if you plan on recording video for longer than a few seconds, the burst speed doesn’t help much. Also, there can be huge variations between the maximum burst read speeds and the minimum sustained write speeds of different cards. It’s not a simple ratio. To determine the minimum write speed of a card, you need to look at its speed-class rating. A speed-class rating means that the card has been verified to never write slower than a card in its classification. Some cards may write a lot faster, especially since the fastest speed class is currently just 30 MB/s, but you can be comfortable knowing that any card with a speed-class rating will never write slower than that speed. Some popular speed class ratings used on SD cards today are:

  • U3- Minimum 30 MB/s Read
  • U1- Minimum 10 MB/s Read
  • Class 10- Minimum 10 MB/s Read
  • Class 6- Minimum 6 MB/s Read
  • Class 4- Minimum 4 MB/s Read

The Fastest SD Cards

Now that we’ve decoded all the technical jargon, it should be clear that if you want the fastest SD cards you can get, look for UHS-II, class U3 cards. And luckily, we carry a number of UHS-II U3 cards from a few manufacturers. SanDisk Extreme PRO UHS-II cards are available in 64GB, 32GB, and 16GB capacities, and offer read speeds up to 280 MB/s and write speeds up to 250 MB/s, which should satisfy the most bandwidth-hungry cameras. Delkin also offers a 32GB card with the same 280 MB/s maximum read and 250 MB/s maximum write speeds. For those willing to trade a little speed for more capacity, Lexar’s Professional UHS-II cards are available in 256GB and 128GB capacities and offer a slightly slower maximum read speed of 150 MB/s.

If you do not have a UHS-II capable camera or computer but still need a fast card, take a look at the SanDisk Extreme Pro UHS-I U3 memory card line, available in 128GB, 256GB, and 512GB capacities. These cards offer read speeds up to 95 MB/s and write speeds up to 90 MB/s, very close to the maximum possible speed of UHS-I.

The Fastest microSD Cards

MicroSD cards are essentially miniaturized SD cards, and share the same UHS and class properties as their full-size brethren; however, as of now there are no UHS-II type microSD cards, so the fastest cards are UHS-I class U3 cards.

Delkin Devices offers UHS-1 U3 rated microSD cards in 32GB and 64GB Capacities. These cards offer up to 99 MB/s read speeds and 50 MB/s write speeds. SanDisks’s fastest microSD cards are the Extreme Plus line, which offer maximum read speeds of 80 MB/s and maximum write speeds of 50 MB/s. They are available in 16GB, 32GB, and 64GB capacities. If you need more than 64GB of space along with high speeds, the 128GB Lexar High-Performace UHS-I microSDXC Card offers read speeds up to 95 MB/s.

CompactFlash Cards

CompactFlash cards used to be the faster and more professional big brother of SD cards; however, several years ago the CompactFlash Association announced there would be no more updates to the format, leaving card performance with a glass ceiling. Today, CompactFlash cards have hit their performance ceiling, and are slower than the fastest SD cards, though they are still quite fast. The UDMA 7 interface has a maximum possible transfer speed of 167 MB/s. Even if a card manufacturer put faster flash memory in a UDMA 7 card, it wouldn’t matter—it would be like plugging an SSD drive into a USB 2 port on your computer (well, not quite that bad, but you get the point). The bright side is that the sustained transfer speeds of CompactFlash cards will most likely be a lot closer to the maximum speed but, since manufacturers don’t share that information, it is difficult to verify.

CompactFlash Card Speed Class Ratings

Many CompactFlash cards have speed ratings like 800x, 1066x, 400x, etc. This speed-rating system is quite old and is based on the data-transfer rate of audio CD files, a paltry 150 KB/s. Needless to say, this doesn’t have much bearing on anything you will probably be doing with your cards, so while you could figure out how fast an 800x card is in KB/s  by multiplying 150 by 800 and convert KB/s to MB/s by dividing by 1,000 (the answer is 120 MB/s) you could also just go by a card’s stated 120 MB/s speed.

The Fastest CompactFlash Cards

Because the maximum speed of CompactFlash cards has been capped at 167 MB/s, for a while almost all card manufacturers offered cards capable of peak read and write performance at that speed. The fastest cards will be UDMA 7 and are advertised as having maximum read speeds between 160-165 MB/s. Lexar’s fastest line of CompactFlash cards is the Lexar Professional series, available in capacities from 16GB and 256GB. Lexar rates these cards at 160 MB/s maximum write speed and 155 MB/s maximum read speed, as well as a minimum write speed of 65 MB/s. SanDisk’s Extreme Pro line of cards also offers similar performance of up to 160 MB/s read and 150 MB/s write speeds. The Transcend Ultimate, Toshiba Exceria, and Delkin Devices Cinema CompactFlash card lines also offer similar maximum read speeds, though their write speeds are a bit slower than the Lexar and SanDisk cards. All of these cards are as fast as CompactFlash cards are going to get; if you want something faster, you will need a different type of memory card.

New Memory-Card Types

XQD Cards

XQD Cards are the reason CompactFlash cards aren’t getting a speed update, as they are the CompactFlash Association’s official replacement for CompactFlash cards. XQD cards offer far higher maximum transfer speeds than CompactFlash, are much smaller, and have a more rugged build than SD cards. There are currently two versions of XQD cards: Version 1.0, which allows for maximum transfer rates of 500 MB/s, and Version 2.0, which allows for speeds up to 1,000 MB/s. While still limited in use, both versions offer faster possible transfer rates than the fastest CF or SD cards available. 

The Fastest XQD Cards

Currently Sony is (still) the only XQD memory card manufacturer, and its newer XQD Version 2.0 cards, available in 32GB, 64GB, and 128GB capacities, are the fastest ones around. All three cards offer extremely fast read speeds of up to 400 MB/s and write speeds of up to 350 MB/s. When it comes to speed, these cards give computer SSD drives a run for their money.

CFast 2.0 Cards                                                     

Despite the fact that CFast cards look almost identical to CompactFlash cards they represent a completely different standard, and will not work in CompactFlash card slots or devices. They are not backed by the CompactFlash association, but are beginning to pick up some steam due to the slow adoption of XQD cards. CFast Cards use SATA connectors to interface with computers and cameras, and the new CFast 2.0 cards use SATA III, meaning they allow for the same maximum transfer rate of 6 Gb/s (750 MB/s) as SATA III drives. While the interface isn’t quite as fast as XQD 2.0, there still aren’t any cards in either format that come close to the maximum possible speed so, at this point, it isn’t really an issue.

The Fastest CFast 2.0 Cards

Currently, both Lexar and Sandisk offer CFast 2.0 cards. The Lexar Professional CFast2.0 cards are advertised as having up to 510 MB/s read speeds and come in 256GB, 128GB, 64GB, and 32GB capacities. B&H also carries SanDisk Extreme PRO CFast 2.0 cards that can reach read speeds up to 515 MB/s, which would make them the top contender for the fastest memory cards mentioned in this article.

So if it’s performance you need, you have to pick sides, CFast 2.0, XQD, or UHS-II-It’s all up to you—well, really it’s up to device manufacturers, but at least now you know how to find the fastest cards available.

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I dont need the fastest that humans can invent, I need something that can handle my max camera output with a bit of room to spare. I wish there was a list of cameras, with maximum MB/s output, and a list of real world read/write speeds for each card out there.

When will this card be available? (Although when shooting stills it is no faster than the SanDisk 90MB/s card.) Just in time for the Panasonic GH4, Kingston announces high-speed SD cards QUOTE: The GH4 is officially able to hit a maximum of 200Mbps if you're shooting full HD with ALL-Intra compression. Luckily, the 30MB/s translates to 240Mbps one you switch from bits to bytes, and with a maximum speed of 90MB/s read and 80MB/s write, the Kingston cards should be able to pipe all those huge video files through without breaking a sweat. The largest of the trio of new cards, the 64GB SDXC version, is also capable of holding 60 minutes of 4K video, or up to 8,000 24-megapixel images.

Hi! I wanted to know what the FASTEST Micro SD card is, as far as read and write speeds. I'm looking for a card 32gb or bigger that I can put in my HTC One S. I don't care about the price, I just want to get a good idea on what to expect.

Thanks for your help!

The fastest microSDHC/microSDXC memory cards we currently carry are the Lexar High-Performance 633x Class 10 UHS-I Memory Card with USB 3.0 Reader, which has a maximum read speed of 95 MB/s (minimum: 10 MB/s) and a minimum write speed of 10 MB/s.  The SanDisk microSDHC/microSDXC Extreme Class 10 UHS-1 Memory Card with microSD Adapter, which has a maximum read speed of 80 MB/s (minimum: 10 MB/s) and a maximum write speed of 30MB/s (minimum: 10 MB/s).

I have a compact flash Ultra 11  memmory card I  have had for years.  This is for my Nikon Coolpix 8800.  Is there something faster?

I take all my pictures in raw.

Hi Jean -

Nikon has tested the following cards and approved their use in the Coolpix 8800:

Nikon FC-CF All capacities

SanDisk Compact Flash (SDCFB) series 32 MB, 64 MB, 128 MB,
256 MB and 512 MB
SanDisk Ultra (SDCFH) series 128 MB, 256 MB and 512 MB
SanDisk Ultra II (SDCFH) series 256 MB

Lexar Media 4× USB series 16 MB, 32 MB, 64 MB, 128 MB,
256 MB and 512 MB
Lexar Media 8× USB series 16 MB, 32 MB, 64 MB, 128 MB,
256 MB and 512 MB
Lexar Media 12× USB series 64 MB, 128 MB, 256 MB and 512 MB
Lexar Media 16x USB series 64 MB, 128 MB, 256 MB and 512 MB
Lexar Media 24x USB series 64 MB, 128 MB, 256 MB and 512 MB
Lexar Media 24x WA USB 64 MB, 128 MB, 256 MB and 512 MB

Renesas Technology (Hitachi) Compact Flash HB28 128 MB,
256 MB and 512 MB

Microdrive: 1GB, 2GB, 4GB

While "WA" (Write Accelerated) cards may be approved for use in this camera, no speed improvements will be noted over non-WA cards.

Other brands and capacities of cards may work, but Nikon cannot guarantee their operation. Check with the manufacturer of the third-party card for compatibility information. Nikon recommends keeping one of the approved cards available for troubleshooting.

Please contact us via e-mail if you have additional questions:

Just bought a new Canon 5d Mark iii and wondering what is the fastest memory card I need (both CF and SD).  I know there are some that are blazing fast but if the camera can't keep up with it I see no reason to spend the extra money.  What are your thoughts?

Canon recommends UDMA Compact Flash memory cards for the fastest performance with the Canon EOS 5D Mark III. Unfortunately, since UDMA 7 has been introduced, UDMA cards have become obsolete, and your best option is to just use a UDMA 7 Compact Flash card, such as the SanDisk 64GB Extreme Pro CompactFlash Memory Card (160MB/s):

For an SD card, the SanDisk 32GB SDHC Memory Card Extreme Pro Class 10 UHS-I is a great choice:

To get the most bang for your buck, I suggest purchasing a high speed/UDMA 7 compliant memory card reader, so you will at least be able to facilitate the high transfer speed when you are writing your files to your computer. My personal favorite is the Lexar Professional USB 3.0 Dual Slot Reader:

the SD drive in the 5d3 is not UHS compatible and is only capable of standard write speeds. no matter what card you use. it's a hardware issue. 

Please update this article. Its one of the first hits on Google if one is looking for the fastest microsd cards and it is two years outdated.

Thank you for pointing out about the search results on this topic. We actually have two new articles posted on this topic in the last day and month.  See the two links below:

Hi Adrian,

Thanks for sharing your comment with us! We took it to heart, and decided to completely rebuild the article. I hope the new information is helpful.


Sam Mallery

What is the advantage of a high speed card ?    Is a slow speed card bad for video taping ?        Will

All cameras that record HD video have their own requirements for the performance speed of the card they record onto.  Most require at least 20-30 megabytes per second or faster sustained write speed in order to properly keep up with the camera’s recording buffer.  Using a card slower than recommended in the camera’s instruction manual could leave you with missing video frames in the recording which will result in a choppy movie. 

Using a card which performs faster than the camera will not cause the camera to perform any faster, but could be beneficial when coupled with a card reader that supports its transfer speed when transferring off the card and onto your computer. 

What card do you recommend for the GoPro Hero3+ Black Edition camera.  There is a wide range of Class 10 microSD cards available in 32GB and 64GB capacity.  I am looking for a firm recommendation that has excellent user performance for this camera.

For the Hero 3+ Black I have been using and recommend the Sandisk 32gb and 64gb Class 10 U3 cards.

great review of storage card formats and capacities...

Great information to know.

Read this...

How about information on performance in temperature extremes?

North Dakota winters we photograph in 20-45 below zero temperatures. Summer time temps(traveling) to 125 above zero and even hotter if one leaves the gear in the vehicle or in direct sunlight.

Which cards perform well in the high and low temperatures?

With regards to extreme tempertatures, SD and Compact flash type memory cards (not microdrive types) are all solid-state which means they have no moving parts, and thus are not affected by cold/heat.  In fact SD cards have been known to be submerged in ocean water for months and still are able to retrieve data.  I've known people who sent SD cards through their home washers and dryers and were still able to retrieve data off of them. 

The better thing to consider in the conditions you've indicated are your batteries, camera's LCD and the camera in general.  Most cameras are specified to work in temperatures ranging from 32-104 degrees Farenheit (0-40 degree celsius). There are a few "rugged" type point and shoot cameras which are rated to go as cold as -14 degrees Farenheit.  For normal cameras, the colder the environment, the faster the batteries will depleat.  Also LCD screens typically freeze or become sluggish as the liquid crystals also have a freezing point within the specs. 

As far as heat in the vehicle goes, do your best to limit the amount of time camera gear sits in the vehicle in the hot summer days.

What about card readers? What are the fastest card readers? Time saved downloading cards can be time consuming on shoots  great article btw  

Sandisk and Lexar both offer card reader capable of up to 500mbps transfer speeds.  See the two links below for details on the options.

This is a very interesting an informative article. An addition that would make it extremely useful is a list of cameras and the card that you would recommend for each one.

We do actually supply that type of information on every camera's product link on our website.  If you visit the page for the camera in question, and regard the "Accessories" tab, we list several recommended/compatible cards at various price points and capacities for our customers to choose from.

I have a Canon 5D MkIII that has an SD card slot as well as a CF card slot.  Currently I only use one SD card but would also like to utilize a second card. Is it advisable or not to use a CF to SD card adapter in my camera so I have the convienence of only using one type of card?  Or should I just buy a CF card?

The CF slot in the 5D Mark 3 is MUCH faster than the SD slot.  It will clear buffer significantly quicker.  If you run 2 cards and write to both, the CF slot will slow down to match SD.  I suggest using CF and have it auto switch over to SD.  Never use SD soley if you're wanting the fastest performance (especially with RAW).

Andrew's reply was spot on, I couldn't say it better myself.

Save this

Thanks so much for the insight.  SD performance and selecting the proper card have been a mystery to me for a long time.  You have cleared up a lot of my questions.

Good comparative analysis. Thanks

  I have a Nikon D 3X  I am curently using 2 Lexar 64 GB 800X CF cards. I have 2 slots for CF cards. What  CF card would you recommend for maximum speed and quality.

Lexar makes excellent CF cards, and their Profesional 800X CF cards would be great for the D3X.  If you are looking for something a bit faster, though, Lexar has come out with their new Professional 1066X CF cards.

My Canon 7D only uses the regular CF cards. It seems that the industry is moving away from these cards. What will I do if the standard CF cards go the way of the Dodo bird?

Peter P


Should that day come (or if you just want to switch from CF to SD cards), you could look into buying something like this:

I read recently that a 5D MKII (or III) user bought something like this and switched entirely to SD cards so that they could use the internal card reader on their Macbook Pro instead of needing to use an external reader. My T3i uses SD cards natively, and I love the convienience of being able to just pop the card out of my camera and insert it in a laptop. Switching to something like this could give you that added convienience and help you "future proof" your 7D.


CF cards are not going anywhere anytime soon.  It will likely be a case where the capacities become to great for the 7D to format, but that is likely even some time off.  Compact Flash cards are still the fastest media option available, and manufacturers keep adding CF card slots to their top tier cameras which require speed.  As an example, the new 7D MK II camera features a CF slot as well as an SD slot.  Those wanting to take full advantage of the camera's features would need to purchase a UDMA 7 CF card which is faster than current SDXC cards can perform.  Its my hunch that your Canon EOS 7D will eventually stop performing before there is a need to worry about memory cards for it going extinct. 

I would not get nervous until manufacturers stop putting CF slots in their top tier cameras - and that hasn't happened *yet*.

I do believe barring acts of God my CF cards will last longer than I will, so no worries there. As far as the camera goes, I agree none are likely to last as long as a CF card, that said I used my 20 years old Canon/Kodak DCS-520 just yesterday. With over 250,000 clicks it is still going strong. And it uses CF cards (via a simple adapter).

Great Article. Just what I needed.

Which one will work with the Panasonic P2 card adapter?

Class 10 SD cards will work with the Micro P2 card adapter in cameras that support using the Micro P2 card adapter. Keep in mind that the SD card has file type restrictions.

This is unquestionably the best article on the state of the Compact Flash industry to date.  Well done!

Wow! This was a great lesson learned.  Looking forward for more

Thanks for the verry good artical. I learned a lot but have been lucky in chooseing the better SD cards for digital photo work.

Thanks, Jim

How do we know the maximum card speed which a camera and card readers, can utilize? 

Some cameras and card readers will specify a maximum (either posted on the manufacturer’s website or printed in the instruction manual). If they do not it is assumed that the camera or card reader will support all speeds of a specific card type be it SDHC, SDXC, CF, etc.

The main issue I have with these data transfer speeds is where the typical electronic radio frequency precautions are staying. If we talk about 500MB/s that means 4Gigabit/s which is strictly taken a waveform in the Gigahertz domain. As far as I know everything above the hundreds megahertz requires special measures in electronics design, lengths of conducting lines and what not. It makes me scratch my head when seeing only 25MHz oscilation crystals on SATA/IDE converters capable up to data transfers ofc150MB/s. Can anyone clarify?

Hi Benzopal -

You may want to contact our engineer friends at LEXAR, SANDISK, or DELKIN for additional insight regarding the underlying science supporting these memory cards.

Please contact us via e-mail if you have additional questions:

Ihave nikon d3300  p.s iwant the best and fastest memory card  thank you


I use a Canon 7D for pictures outdoor and at events of our organization, what is the best card I can use for the speed I need ?