Pentax K100D Memory Card Compatibility

The Pentax K100D uses SD memory cards. 32GB is the biggest capacity SD card that will work in the K100D.

SD memory cards that satisfy the SDXC or SDUC specifications will not function properly in the K100D. These cards will be 64GB or larger, so they can easily be avoided.

Affiliate Advertising Disclosure

Outside the Shot is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to

As an eBay Partner, I may be compensated if you make a purchase. I also participate in affiliate advertising programs with KEH and Adorama. More can be found on the Affiliate Discolsure page.

The SDHC format was announced in 2006. All 32GB cards that are currently being produced will have almost identical performance. You cannot go wrong buying the cheapest class 10 name brand card. At the time of writing this, the PNY Elite 32GB SD memory card has the best price.

Here are several choices to pick from that will work correctly in the K100D. With any of the cards below, you will not have to be worried about slow functionality or SD memory card glitches.

PNY Elite 32GB SD Memory Card
PNY Elite 32GB SD Card
Check price on Amazon
  • Sequential read speed of up to 100MB/s
  • Class 10, U1 rating delivers speed and performance for full HD photography and HD videography.
  • V10 video speed rating to capture uninterrupted HD video at 1920x1080 format
  • Compatible with point & shoot cameras, DSLR cameras, standard & advanced HD-enabled video cameras, and more
  • Reliable & Durable: Magnet Proof, Shock Proof, Temperature Proof, Waterproof

SanDisk Ultra 32GB UHS-I SD Card
SanDisk Ultra 32GB SD Card
Check price on Amazon
  • Quick transfer read speeds up to 90MB/s.
  • Write speeds are not capable of recording 4k video.
  • Class 10 rating for Full HD video (1080p).
  • Waterproof, temperature proof, X-ray Proof, magnet-Proof, and shockproof.

Samsung EVO Plus 32GB SD Memory Card
Samsung EVO Plus 32GB SD Card
Check price on Amazon
  • UHS Speed Class 1 (U1) supports Full HD video and burst shots. 130MB/s transfer speeds1 let you upload footage to your PC in an instant.
  • Built to survive tough conditions and heavy usage, whether you’re at home, outside, or on the go. Backed by 10-year limited warranty.
  • Highly durable with comprehensive 7-proof protection.
  • Backed by a 10 year warranty.

Premium quality memory cards are produced by both SanDisk and Lexar. Low-priced third-party brand names ought to be avoided.

Memory card problems, like a loss of all of your shots because of data corruption, is more inclined to occur with inexpensive cards. The reduction in build quality is not worth the minimal amount of savings.

Purchase a reduced capacity memory card should you want to reduce costs. They tend to be slightly lower in cost and you won’t need to worry about the SD card becoming corrupted.

Understand that, SD card problems are very infrequent. Only only two cards have become corrupted out of the considerable number I have acquired over the years. The two memory cards were pre-owned house cards that were bundled with the purchase of pre-owned digital cameras.

Currently, 4 different specs of Secure Digital (SD) memory cards exist. The Pentax K100D can only use SD memory cards. The benefit is that there is an increase in the transfer rates and maximum storage capacity with the release of every updated specification.

Secure Digital memory card readers are backward compatible. A card reader built into a digital camera that can use SDXC cards will also be able to use SDHC and SD memory cards.

The Pentax K100D’s card reader can only read the original two SD card specifications. SDUC or SDXC memory cards are not going to function correctly.

  • Secure Digital (SD) - These memory cards have a maximum capacity of 2GB and are compatible with the K100D.
  • Secure Digital High Capacity (SDHC) - The capacity of these memory cards range from 4GB to 32GB and are also compatible with the K100D.
  • Secure Digital eXtended Capacity (SDXC) - The capacity of these memory cards range from 64GB to 2TiB.
  • Secure Digital Ultra Capacity (SDUC) - The capacity of these memory cards range from 4TiB to 128TiB.
SD card contacts
SD Card Contacts

Attempting to use an SD memory card that is 64GB or larger in size in the K100D results in the camera to display an error.

Use an SD memory card with a storage capacity of 32GB or less to avoid the problem.

If you have an SD memory card that is 32GB or a smaller capacity, and the card is not functioning correctly, format the card while it is in the camera.

Here is an estimation of the total number of large JPEGs you could expect to save on an SD card.

  • 4GB - 1920 images
  • 8GB - 3840 images
  • 16GB - 7680 images
  • 32GB - 15360 images

The speed rating for SD cards is determined by sequential read and write speeds. The speed of the card is important when many shots need to be written to the SD card.

SD Card Speed Class
SD Card Speed Class

The Class speed rating of an SD memory card is related to the sustained write speed of the SD memory card. A Class speed rating of 2 means that the memory card can sustain a write speed of more than 2MB per second.

  • Class 2 - 2MB/s
  • Class 4 - 4MB/s
  • Class 6 - 6MB/s
  • Class 8 - 8MB/s
  • Class 10 - 10MB/s

The maximum rating an SD card can attain is Class 10. There are memory cards that are significantly faster than 10MB/s. Those SD memory cards use other solutions, such as UHS (Ultra Highspeed Bus), which use a different rating specifications.

Sustained write speeds of 2MB, 4MB, 6MB, or 8MB per second means the card has a speed class of 2, 4, 6, or 8. Cards that have write speeds of 10MB/s or faster are rated as Class 10.

Buy an SD memory card for the Pentax K100D based on price. An expensive card isn’t going to improve performance. As long as it is a speed class 10 card, you will be fine. My recommendation is the PNY Elite 32GB SD memory card.