Sandisk 32 GB Extreme SDHC Cards (SDSDX3-032G-A31)

I don't know if this info is of interest but I just got off a call to Sandisk and ultimately to their "technical support for professional memory cards". My question to them was what is the difference between their item numbers SDSDX3-032G-A31,SDSDRX3-032G-A21, and SDSDX-032G-X46D. All of these are shown on their website as 32 gb SDHC class 10 cards with a 30 mb/s' transfer speed. The final answer from their "experts" is there is no difference except for the packaging. They are the same card. SDSRDX3, SDSDX3 and SDSDX all specify the Sandisk Extreme SDHC card: the 032G, of course, specifies the capacity in gigabytes; the A31, A21 and X46D identify the different manufacturing sites where the cards were made.My next question to them was whether the listed 30 mb/s' read/write "Max" speed was theoretical or actual as I require a card for a video camera with a 24 mb/s' tranfer rate to a memory card. The response was that the card will maintain whatever speed the host is sending to it up to a maximum of 30 mb/s'. (I hope they are right)I hope this helps someone in addition to me select the right Sandisk SDHC card for their requirements . I can't believe how confusing this process has been!Now, in the interest of full disclosure, I have no clue what the rating should be since I have only just now ordered the card from Amazon. I put this information in the review section now because of all the apparent confusion/irritation contained in the reviews because customers ordered this card with a specific Sandisk item # displayed on the Amazon website and then received a card with another Sandisk item # on it.I will update this "review" after I have time to "play" with the card in my camcorder.

When I received the SD card I didn't think about checking and comparing the product# on the box to the Seller's description prior to opening it. They didn't match, and I was like, "F#$%! I got ripped off!" But I did some research and compared the Seller's description, which is "SDSDX3-032G-A31", and the one I received - "SDSDX-032G-X46". The card I got was the upgraded version (based on what read on the Sandisk forum)! It's the newest version that complies with the new SD 3.0 specs. It's also a UHS-1 card. So, I'm happy (and relieved).In terms of performance, I compared the write speed of my old 16GB Class 6 Patriot SDHC card to the Sandisk. I know we're comparing DIFFERENT CLASSES, but I was curious. I transferred a 2.5GB video file to each card, and the Patriot wrote at 10.2 MB/s while the Sandisk wrote at 19.2 MB/s. That was definitely a big improvement, but it wasn't near the 30MB/s as advertised on the box.For my Canon T3i, I did a continuous shoot (RAW + Large JPEG) and after the buffer filled up, it started to shoot at 1 photo per second. With the Patriot it was roughly 1 photo per 2-3 seconds once the buffer was filled. After that I waited to see how long it will take to do a complete Buffer Flush and have the camera ready to do a full shoot again. The Sandisk took 4 sec to do a complete buffer flush, while the Patriot took about 7-8 sec.So overall, I'm happy with the improvement and relieved. I didn't realize while doing some research on this card that there were some counterfeits being sold on eBay (not to knock on eBay).

This card is very fast. I had a Transcend card that did about 16mb/s transfer (the most popular little blue card when you search for SD cards on Amazon). That other card is great but it was not enough to film 1080p video on my Canon T2i. The video was choppy because the buffer couldn't load the data to the card quick enough.I get about 26mb/s with this new card. It says 30 but I'll blame my .99 cent card reader for the slower (but still fat) response time. Films 1080p smoothly and transferring to the computer is a snap. It's so fast I have to go make sure it transferred, no loading bar or anything for 500mb transfers. The card feels sturdy too. As sturdy as a card can feel I guess. No complaints for performance. ONLY complaint is price, but you get what you pay for with this. It doesn't disappoint.I wish they made a 64GB version. I'd pay for it.UPDATE: Plugged the card in to my laptop and tested speed. Never dropped below 30MB/s. Excellent and reliable.UPDATE 2: They sent me the cheaper A21 card as the reviewer after me received as well instead of the advertised A31. Not sure how many people got the wrong card. Performance is still kicking at 30MB/s so honestly I'm fine with it. Might submit a request to change the product description.UPDATE 3: This card is the A31. The A21 performs at 20MB/s and only goes up to a 16Gig. My card was a 32Gig at 30MB/s as described. I think it's just the sticker and packaging might have been repurposed. I have no complaints with this card, still performing great after a few weeks of use.

The actual card is not the A31 but the older A21. As the other reviewers pointed out, the original barcode was covered with another sticker to show A31 and packaging is for A21. You can buy the A21 for $5 less so I felt I was ripped off by Amazon. I have not decided yet whether to return or keep it. This is my first disappointment with an Amazon fulfilled purchase.Update Sep 22, 2011 # 1: After communicating my situation to Amazon CS, I was given a significant discount (sorry, can not disclose). So I'll be keeping this card even if this is not originally what I intended to buy. Great support from Amazon and I'm giving this 5-stars.Update Sep 22, 2011 # 2: I performed benchmark tests using a Transcend card reader plugged into my laptop & the card reader installed on my Alienware PC. I used HD Tune pro. I got average read speeds of about 19 MB/sec. This is the same as the 8GB class 6 Sandisk SDHC card I bought several years ago. I also tested my other class 6 SDHC cards (2 Transcend & 1 Patriot) and I'm getting about 17 MB/s. I'm not sure if the bottleneck is the card reader but I did not expect to get this type of speed for a class 10. I'm going back to a rating of 3 stars. Will find out if there is a bottleneck. I'm disappointed at this point but I got the discount to offset for the slower speed... a class 6 - 32GB card.