Before You Buy a Memory Card....

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Re: Before You Buy a Memory Card....

Postby RationalKeith » Fri Oct 15, 2010 10:22 am

Oh, I omitted a useful claim - that the malware specifically targetted an industrial control system model that is believed to be used in Iranian facilities.
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Re: Before You Buy a Memory Card....

Postby RationalKeith » Mon Nov 01, 2010 8:24 am

The Iran claims have been questionned, see my posts in the So Sue Me thread.

The point remains that USB sticks are a means of spreading malware, as floppy diskettes were years ago.
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Re: Before You Buy a Memory Card....

Postby RationalKeith » Tue Apr 01, 2014 11:29 am

And an update, just to bother the person who whined about using an old thread...

Beware of memory cards/sticks over 32GB.

They require use of the exFAT file system, NTFS is limited to 32GB.

There are patches for Apple and Microsoft o/s, Microsoft Update pushes one for Windows XP but it does not work on 64GB SD cards from two good brands- cannot use more than 32GB. (Windows XP works.)

A problem with newer things is people not fully understanding the specification or simply not following it correctly. Even worse when two companies didn't, one's software will trip over the other.

I'll finger IBM Thinkpads of several years ago for SD card problems with certain card vendors, and SanDisk when 4GB sticks first came out.
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Re: Before You Buy a Memory Card....

Postby PMC » Tue Apr 01, 2014 8:08 pm

Want to say to Rational Keith that your statement on NTFS being limited to 32 gig, is only for that card.... any 320, 500 gig hard drives use NTFS etc.

SD cards don't last forever, and can be damaged. They are great to load with data, and then only for read of that data ( playing mp3's etc). Continuous rewriting will burn them out, since they can only be rewritten X number of times. The larger the files you create and delete, the faster the overwrite occurs.

USB memory sticks can vary. Any bought in main stream stores are usually good. They can be smoked by improper inserting into the holder. They also need to be shut down or set for removal. It is the operating system that decides when to write the data that you have copied to it. I have seem a stick wiped empty because it was pulled out while it was being written to.

Branding should not be a factor in choice. I had a Lexar 32 gig stick that fried in a week... and I have two of their SD cards over a year old, that see some writing, and they work great. Every Sans card that I have, some two years old, all continue to be good.

Use a USB memory stick to backup your SD card. Another point on these cards, the contact points on the card don't like pizza sauce and other related food stuffs. :wave:
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Re: Before You Buy a Memory Card....

Postby Mr.e. » Wed Apr 02, 2014 6:31 am

Well how about after you buy a memory card!
A while back I was transferring some music from my tape deck, to my computer, and after the pain of compressing, and transferring everything to mp3, and finally to the sd card, I walked the sd card over to the second computer tower which was already turned on and inserted the card. Well I instantly wiped out about 400 songs!! YIKES STATIC ELECTRICITY, OH NO! Yep instant fry. Now especially during the winter I discharge all that nasty static, before going near the computer.
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Re: Before You Buy a Memory Card....

Postby jon » Wed Apr 02, 2014 6:49 am

While I agree with PMC's point that Brand does not determine Reliability in either kind of Memory Stick, I do know from experience that Brand and even Model can matter in devices with specific characteristics.

My previous digital audio recorder, a TASCAM (TEAC's Pro Audio division), would fail after about 3 hours into a recording of CD quality WAV format when I used a Kingston SDHC card. TASCAM Support then told me that they had both problems in the lab and lots of customer complaints about Kingston cards not working on that device. They pointed me to their official published list of cards they had tested, but also made the general statement that they had never had a card that failed from two specific brands.

For most devices, you are unlikely to find such a generic statement as "any of these brands", but it is still generally safe to use a different size of the same brand and model as the ones on the manufacturer's published list in the manual or on their support web site. Model matters because it denotes both speed and other characteristics.

In general, real-time recording devices are the ones where you need consistent performance. A computer should be the most tolerant because it will silently retry if the card does not read or write at any given moment. Real-time recording of audio or full-motion video are the most demanding, especially at higher resolution. In theory, still cameras should be a bit more tolerant.


32GB is a limit for another reason, too: SDHC does not support larger sizes. That means that 64GB cards are SDXC, but older devices only supported SDHC. Even SDHC devices can have published limits. I've seen 16GB and 8GB limits even on products currently being sold.

I'm not sure that NTFS is worth the hassle. FAT is not secure, but it also avoids the Permissions Issue that can occur if you move from one computer to another. NTFS knows the User ID that wrote the data; FAT doesn't.

I once used a FAT-formatted SD card to transfer a web site off a very old web-based FTP program used by a web hosting company, because saving the files to my hard drive made them unreadable. The FTP program stored them under the User ID of the web host! Since FAT doesn't store User ID, I was able to retrieve them if stored on an SD card.


I also agree with PMC that SDxx cards are not fragile, but they do not react well to physical abuse. USB memory sticks are generally more robust. You can generally mail either, but only SDxx cards are thin enough that they can be mailed as Letter Mail. I found really nice clear holders/cases on eBay from China (cheap with free shipping) for SDxx and microSDxx cards, and they really help avoid damage at home, on the road and in the mail, as they are still thin enough to go Letter Mail.


Don't have a card reader on your computer? The Kingston MobileLite series are $9.95 to $12.95, depending on whether you need USB 2 or 3. They plug into any USB port.

I think it would also solve Mr.e.'s static electricity problem if you walked the card reader over, with the card inside, rather than the card itself.
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Re: Before You Buy a Memory Card....

Postby Toomas Losin » Wed Apr 02, 2014 9:40 pm

PMC wrote:Continuous rewriting will burn them out, since they can only be rewritten X number of times. The larger the files you create and delete, the faster the overwrite occurs.

One shouldn't worry about this unless one has reason to worry. The typical 100,000(?) write cycle spec will provide a long service life in normal use.

Reason to worry includes having an application that wants to frequently update the same small file or frequently does a write/delete/write cycle of large amounts of data; it's the frequent, automated, reuse of flash sectors that wears them out quicker than one might expect. There's an interesting Wikipedia article about wear leveling, the technique used to (hopefully!) minimize this wear.

I have a 32 GB SDHC card which sees about 8 GB of writes each night for unattended DX. It's been in service for three years and I expect it to still be usable long after the technology is obsolete.
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Re: Before You Buy a Memory Card....

Postby PMC » Thu Apr 03, 2014 7:08 pm

Agree on the burn out rate.

Found this site in my travels, and the images eat up gigabytes, but are impressive. The concept is simiar to google maps, but in horizontal. Click the image to get into it and hold the mouse button down to move the image.... There is a control box on the upper right. G. Bush Jr and his wife are behind Obama... click to find them and anybody else that was there.

http://gigapan.com/gigapans/033ef14483e ... irect=true
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Re: Before You Buy a Memory Card....

Postby RationalKeith » Fri Apr 11, 2014 9:58 am

Erps, My sentence about o/s patches to accomodate xFAT should say that devices with exFAT file allocation table format work with Windows 7, the problem is with Windows XP.

I should add that problems may be different with SD cards and USB memory sticks, as the drivers are different. (Cards in that wide slot in many laptops, I don’t know about – those aren’t all the same interface. It’s like VOA switching to Swahili when I was listening from a mountain top decades ago – probably talking about things we’d recognize but without fluency or a translator it’s meaningless.)

In limited testing 64GB USB sticks work at that capacity in Windows XP but cannot be formatted.

And that USB-connected HDDs are different interface, NTFS supports to at least 2TB.

As for recovering data:
- beware that deleting from SD cards and USB cards does not normally put deleted files into Recycle bin
- there are utilities to recover data from them, I’ll look up my notes
- for recovering from HDDs, I recommend ReclaiMe, it can recover much data from a reformatted drive.
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Re: Before You Buy a Memory Card....

Postby RationalKeith » Mon Apr 21, 2014 3:00 pm

Ah, found my notes on file recovery:

ReclaiMe can recover data from USB sticks not just HDDs, don’t know about SD cards. Even recovers pieces of files where file was partly over-written (as Windows does when re-using space of deleted files which may be stored in fragments – put DeFrag on you maintenance checklist :-), but you’d have to crawl through looking at a huge number of pieces to find what you want.

I’ve used undelete360 on USB sticks, it handles SD cards as well. Claims to handle HDDs too, however hung on sizeable drives and is tricky so I paid $80 for a license for ReclaiMe. (The web site for undelete360 has some overly obvious downloads for other things, and ESET security suite blocked download of the FileRepair program also offered there – apparently it can repair some files, after you recover them.)

Lexar may offer a routine, perhaps bundled on their memory devices, I was not impressed with the one I tried.

Trinity Rescue Kit may be worth trying, it has some imaging capability as well.

Then there are specialists in data recovery, probably starting at a few hundred dollars and zooming upward. Not likely to recover data from an SD card zapped with static, but if you are desperate....
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Re: Before You Buy a Memory Card....

Postby jon » Mon Apr 21, 2014 3:56 pm

As for available sizes, TigerDirect.ca currently has a sale on 256GB SDXC memory cards for $109. As for USB Flash Drives, 1GB ones are available. ....for $1400.
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Re: Before You Buy a Memory Card....

Postby Mike Cleaver » Mon Apr 21, 2014 8:24 pm

Just some other things to check before you think your memory card, usb stick or external (or internal) hard drive has died.
USB sockets and plugs are crap, just like the RCA plugs for stereos and video recorders of days gone by.
There is no locking mechanism to ensure the two stay connected properly.
Check to see all your devices are properly plugged in.
Memory card contacts can become contaminated with gunk, both the card and the insertion point.
A little rubbing alcohol on a q-tip might be the solution when a card won't read or write properly.
With external hard drives, make certain that the power supply or little USB card inside the case hasn't died.
These are as cheaply built as possible and often fail, making you think the drive is toast.
Buy a jig from NCIX or other "real" computer store, not the big box ones, that will replace the "bits in the box" with a more rugged supply and USB connection and plug the drive into it.
The one I have is good for old and new drives.
Too many people have asked me if their corrupted drives or dead drives can be saved.
Often, the drive is fine, as is the card or the USB stick.
It's other parts between the drive and device that have failed.
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54 years experience at some of Canada's Premier Broadcasting Stations
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Re: Before You Buy a Memory Card....

Postby Toomas Losin » Mon Apr 21, 2014 9:19 pm

Mike Cleaver wrote:Just some other things to check before you think your memory card, usb stick or external (or internal) hard drive has died.

Another one: If one bends over too much with a USB flash drive in a pants pocket the wrong way then the strain can cause the USB plug contacts inside to break away from the circuit board. When this happened to me I was able to resolder the connections to make it work again.
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