1. We just purchased a new NX5u and the question is regarding SDHC cards. I was picking brains of a B&H rep for a minute and he told me that 24mbps is an absolute minimum for NX5u. I saw Transcend cards which are 20mbps and I think people here use them without problems. Please, confirm.

2. Are there other less expensive options besides 32gb Transcend for $108 from B&H?

3. We are producing a small talk show from our house and the local cable channel haven't switched to HD yet, so we give them all the footage in SD. So, for the time being, what are my options with SDHC cards on a budget to shoot in SD mode?

Thank you all in advance.
KC.

NewEgg has the Transcend SDHC 32Gig class 6 cards for $99.00 with free shipping, I have 2 that I use with my HDR AX2000...They work perfectly on all my High Def footage needs.....

Dave, thank you for your quick reply. B&H has a class 10 transcend 32gb for $108, doesn't sound too good to go down to class 6 for $9.

Transcend 32 GB, class 6 on Amazon.com for $89.00, free shipping.

Adorama has the 16gb Lexar Class 4 for $24.95

LSD16GBSBNA060 Lexar 16GB 60x Platinum II Series, Secure Digital High Capacity (SDHC) Memory Card (http://www.adorama.com/ILXSD16GBP2.html?emailprice=t&utm_source=rflaid62905&utm_medium=Affiliate&utm_campaign=Other&utm_term=Other)

and class 4 will support HD recording? B&H rep told me minimum I need is class 10... I'm confused.

You don't need class 10 cards, class 4 and higher all work. I have all class 4's and have recorded at the highest bit rates many times with no issues. Don't confuse MB with Mbps, it sounds like B&H is using this confusion to upsell more expensive cards.

Ben


Also see this post:

http://www.dvinfo.net/forum/sony-nxcam-hxr-nx5u/478742-sdhc-cards-hxr-nx5.html

Check you camcorder's manual. For the HXR-NX5/HDR-AX2000, class 4 cards are good enough.

On the local cable channel still on SD--shoot and edit in HD and output to SD, so when they do go HD, you'll have archived footage already in hi def.

Heath

Maybe there is some confusion over acronyms? Sometimes you have to read closely to see whether they are describing MB (megabytes) or mb (megabits). 20 "MBps" is a lot more than 24 "mbps"

The cards are 20 MBps, sometimes abbreviated as 20 mBps, and which refers to megaBytes per second. Each "Byte" equals 8 "bits."

The NX5 records AVCHD at up to 24 Mbps (or mega-bits per second). To convert that to "megaBytes" you divide by 8. So 24 Mbps AVCHD is actually 3 MBps.

Incidentally, 24 Mbps is the "maximum" AVCHD recording rate for the NX5. (This is the "FX" setting.) The "absolute minimum" rate is the "LP" mode at 5 Mbps. It seems to me that the B&H rep may have been expressing a personal opinion that you should always use the FX settings (24 mbps) with the NX5 to get the best pictures or he/she may have been saying that a 20 mBps card is the absolute minimum card to use when shooting FX AVCHD on the NX5.

For shooting to SD, you've got basically two options with the NX5. One is to record at HQ 480/60i mode (9 Mbps Mpeg 2) for standard def video. The other is to shoot in FX AVCHD as Heath recommended (as do I.) Remember when shooting to give due respect to SD 4:3 framing if that is your delivery format. You output your edited HD footage to whatever format the cable company wants (DVD/Mpeg2? AVI or Quicktime file?)

Another vote for class 4's. Been using them for a year with no problems at all. HD max rate on Canon hf-s11 and panny tm700.

So to sum it up, a class 4 card has a minimum transfer rate of 4MBps. Mulitiply that by 8 and you get 32Mbps which is faster than the 24Mbps the NX/AX cams record, so class 4 is enough with some left over :-)

If you observe the LED's in the back, the recording is not happening in realtime. The camera records in a memory buffer a few seconds then transfers it on the cards. This means that the transfer speed is actually bigger than 24mbps. So if the cards have a bigger class leads to quicker transfer speeds (up to maximum bandwidth allowed by the components of the camera) and less usage of the cards that could mean less possibility of cards failures. I use only MS Pro Duo and I noticed that the LEDs are red much shorter time than green.

That’s absolutely correct. To secure a constant writing speed (necessary for programming memory cells of a memory card) camcorders use a buffer. If the memory card’s writing speed is not adequate, the buffer overflow may happen which would lead to dropouts in video recording or a complete loss of information.

The NX5/AX2000 buffer size is about 9 MB, and at the highest image quality setting it’s date rate is 3 MB per second. Therewithal, speed measurement for a class 6 memory card is 6 MB/s (for the class 4 it will be 4 MB/s correspondingly), therefore, it seems quite all right to use such cards in the NX5/AX2000.

And most of the time, it will be so. However, it’s important to remember that speed measurement is based on the best fragmented state where no memory card is occupied. Heavy fragmentation can reduce write speeds, consequently higher SD card speeds help compensate for fragmentation.

Practically this means that if you never erase recorded clips on the fly and clean up your memory card each time by erasing all the clips at once, you probably will be okay with the class 6 (or even with the class 4).

By, 'erasing all the clips at once' you mean reformatting the card in camera, right?

No, I meant just to delete all movies/still images at one time.

Mind you, you must avoid formatting your memory card as much as possible (meaning no reformatting every time you simply want to delete data or free space on the card).

As a matter of fact, every flash memory card does wear down (and cheap cards tend to wear the first few bit the most, while the last bit go almost unused). Formatting/reformatting operation merely increases pace of such deterioration.

Is that right Arkady - that reformatting reduces the card's life-cycle? I've never heard of that before, so is this common knowledge? But doesn't a reformatted card present the camera with a 'clean sheet' with no defragging needed, so to speak?

tom.

Hi, Tom

Here are you questions and my answers.


1. Is that right that reformatting reduces the card's life-cycle?

A memory card, based on the flash non-volatile storage technology, stores information in an array of memory cells made from floating-gate transistors, so that each cell stores only one bit of information. A single-level flash cell in its default state is logically equivalent to a binary "1" value.

During reformatting process, each cell of a memory card is erased. To erase a flash cell (resetting it to the "1" state), a large voltage of the opposite polarity is applied. Unfortunately, this can be done only a finite number of times. In technical terms, flash memory has a finite number of program-erase cycles (typically written as P/E cycles).

2. But doesn't a reformatted card present the camera with a 'clean sheet' with no defragging needed?

It’s not necessarily so. Fragmentation happens when you delete one or more clips surrounded by others and then start to recode a new clip. Trying to save free space on the card the camcorder processor may split a new clip into parts filling up the gap.

To avoid this, do not delete particular clips but erase them all.

3. Is this common knowledge? Yes, Tom, it is. Memory wear is the known limitation of flash memory technology.

Thanks for your answers Arkady. You learn something new every day, and it's this that makes life so interesting.

Will this card work fine? I bought four.

Ebay Item number: 120609547882

I don't mean to throw salt on anyone's wounds, but this question came up many times on DPReview forums, and it's been actually cleared that you don't kill free memory flash space by reformatting, this is a simple experiment that takes 2 minutes to open chat windows from two major player's websites.

Sandisk's response about reformatting:

Keith B.: Hello, thank you for contacting SanDisk. My name is Keith B.. Please give me a moment while I look into your question.
KC Kennedy: Good afternoon, I have a question regarding formatting and space on SDHC memory cards. Could you please, verify something for me?
Keith B.: Please tell me what is written on the face of the memory card?
KC Kennedy: A much more knowledgeable friend of mine told me that the more I format my SDHC card, the less free space I get after each formatting. Is this correct?
KC Kennedy: This is just a general memory question, I own many SD cards...
Keith B.: Ok.
Keith B.: This is not correct but formatting will delete all the data saved on card and the available space will remain the same even if you format it number of times.
KC Kennedy: may I refer to the original source?
KC Kennedy: Here are you questions and my answers.


1. Is that right that reformatting reduces the card's life-cycle?

A memory card, based on the flash non-volatile storage technology, stores information in an array of memory cells made from floating-gate transistors, so that each cell stores only one bit of information. A single-level flash cell in its default state is logically equivalent to a binary "1" value.

During reformatting process, each cell of a memory card is erased. To erase a flash cell (resetting it to the "1" state), a large voltage of the opposite polarity is applied. Unfortunately, this can be done only a finite number of times. In technical terms, flash memory has a finite number of program-erase cycles (typically written as P/E cycles).

2. But doesn't a reformatted card present the camera with a 'clean sheet' with no defragging needed?

It’s not necessarily so. Fragmentation happens when you delete one or more clips surrounded by others and then start to recode a new clip. Trying to save free space on the card the camcorder processor may split a new clip into parts filling up the gap.

To avoid this, do not delete particular clips but erase them all.

3. Is this common knowledge? Yes, Tom, it is. Memory wear is the known limitation of flash memory technology.
Keith B.: Please allow me a minute.
KC Kennedy: sure, I appreciate your time and effort
Keith B.: According to the information mentioned above you can say you have the certain numbers of read/write cycle on a flash memory card. The information provided by you do not indicate that formatting the card will have a impact on available space but to a very minimal extent it will have a impact on life cycle of card.
KC Kennedy: Thank you, Keith
Keith B.: Have I provided you with all the required information, today?
KC Kennedy: Yes, Sir. Absolutely, have a great day.
Keith B.: Is there any thing else I may assist you with?
KC Kennedy: not any longer, thank you
Keith B.: We'll send you the incident number that you can use to reference this chat, and also, the chat transcript in a follow-up email. Thank you.
Keith B.: Thank you for contacting SanDisk, and you have a great day, KC.
Keith B. has disconnected.

LEXAR's REPLY:

Welcome to Lexar Media's Live Chat. A Live Chat agent will join you in a moment... Please do not begin typing until you have been connected to an agent.
Hello, my name is Sathya . How may I help you?
KC Kennedy: Good afternoon, I have a question regarding formatting and space on SDHC memory cards. Could you please, verify something for me?

KC Kennedy: A colleague of mine mentioned that the more often you reformat SDHC memory card, the less free memory you get on it. Please, verify if this really is the case
Sathya : No, it is not like that.
KC Kennedy: please, explain
Sathya : For example if you are using 4 GB SDHC card the actual space you will get approximately 3.73 GB the remaining space would be allocate to inbuilt memory on your computer OS.
Sathya : Normally formatting will erase bad sector and if any data in your memory card.
Sathya : And it will reset the memory card to original factory settings.
KC Kennedy: So, formatting card completely even 100 times will still make that same 3.73gb of free space available for recording?
Sathya : Exactly.
KC Kennedy: thank you very much, have a great day
Sathya : You are welcome.
Sathya : Is there anything else I can help you with?
KC Kennedy: no, Sathya, thank you for your help
Sathya : It's my pleasure to assist you.
Sathya : If there is nothing further I can assist you with, I’d like to thank you for visiting Lexar..com. Have a great day.

I don’t mean to turn this chat into a theoretical conference but to verify that the memory wear exists as a real fact of life would take you even less than 2 minutes if you bothered yourself to open Wikipedia website in the first place instead of websites of memory card manufactures.

There you would learn that flash memory does wear down, and cheap cards tend to wear the first few bit the most, while the last bit go almost unused.

To prevent this high quality cards use what is known as "wear leveling" to remap the starting point, resulting in a more even wear pattern. Sure this mechanism works, and you cannot kill your card even after hundreds of reformatting cycles.

But also without a doubt in the long run the less you reformat your card the longer it will last.

Ok, next time I'll go to the first source, Wikepoedia (source without an author).

How about this?

Wear Out

Another peculiarity of NAND Flash as a storage medium is its increasing susceptibility to bit errors after having gone through a certain number of program-erase (P/E) cycles. The number of cycles varies, depending on density (storage capacity per physical area), vendor, and NAND Flash type.

That was an exact quote from the paper titled “NAND Flash Solid State Storage for the Enterprise: An In-depth Look at Reliability, April 2009” written by Jonathan Thatcher (Fusion-io), Tom Coughlin (Coughlin Associates), Jim Handy (Objective-Analysis), and Neal Ekker (Texas Memory Systems).

Is this better than what you called no-name source?

Yes, you are right. Now I know I was wrong :)

Ebay Item number: 120609547882

Sure thing cards turned out to be fake, from serial numbers (all four have the same #'s), to wrong packaging, wrong color of the card, fake holograms, fuffer overflow at highest quality recording...).
Very sad, and seller claims that I don't know how to use memory cards. Sure thing negative feedback will follow as soon as I get my PayPal refund.

Who has lowest priced Class 4 cards in 16-32gb range now?