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Flash Memory, a Look Back
An anonymous reader writes "XYZComputing has an interesting roundup of CompactFlash cards manufactured between 1998 and 2005. The cards go through a number of tests to see how the many changes which CF cards have undergone have affected their performance. One of the most interesting aspects of the article is a head-to-head comparison of "extreme" speed flash memory and that same company's less expensive standard model."
I find the difference between the two top Sandisk cards (the normal and the Ultra III) very interesting. I've been meaning to buy a new memory card for my camera (I'd like a bigger one) and knowing that the difference is that little could save me some money.
But that one card's access time is just HORRIDNESS. As the author said, that was bundled for free with a camera, and you do get what you pay for. Wow.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
I got my first flash memory drive about two years ago. For me, its the best thing to happen to storage in years.
With that said, I am still surprised by the large number of floppies used by students and teachers in our education system (K-12). I did IT consulting work at a charter school for two years (just left for a higher paying job), and I had numerous cases where students (and even teachers) were saving documents directly to floppy disks! They would be distraught beyond description when they found out the disk went bad as it was crushed and pounded inside of a backpack, and the data was destroyed. I told everyone that had this happen to them to switch to usb flash drives and it has made the biggest difference.
My usb drive has been through the washing machine, dropped, stepped on, and plugged into hundreds of machines over the last two years with no data integrity loss. It holds all my software utilities for my job, and two years worth of school work. I've had hard drives fail, CD that stopped reading, and the aforementioned floppy disks. I would say that flash memory has been the most reliable form of data storage I have used in my 20 years of using computers.
"Technology gets faster and cheaper with time."
Pretty much every single measurement they do is useless for the #1 use of compact flash cards: higher end point&shoot and low-end DSLRs cameras. Why do I care how much CPU my computer takes to read data off a card, or how fast it can read the data? Those are both offline processes that happen while I'm shooting more pictures my the other card. The only statistic that matters to the primary customer use is the sustained write rate, which this page completely ignores.
Rob Galbraith has a long more comprehensive list of CF cards rated by transfer to computer performance here:i d=6007-6133
i d=6007-6111
i d=6007
http://www.robgalbraith.com/bins/multi_page.asp?c
The Sandisk Extreme III 1G vs Sandisk Standard 1G on the CF to computer test scores 12.859MB/sec vs 2.377MB/sec
In my Canon 10D
http://www.robgalbraith.com/bins/multi_page.asp?c
1.387MB/sec vs 806K/sec (sorry slower older camera that can't reach the speeds of the newer DSLRs)
READ and WRITE speeds may be different. I'm more concerned with how quick the camera writes to the card (Galbraith's numbers) than how quick I can read the data off the card (XYZs numbers)
However...for my money battery life is more important. I'm more concerned with how much battery life the Extreme III vs the Standard card consumes.
I have a 128Mb Sandisk Standard and it drains the battery on my Canon 10D much more quickly than the 512Mb Extreme III that I have. And when the battery gets low on the camera I get an "Error #2" very quickly when using the standard card.
Unfortunately neither Galbraith or XYZ give any numbers on power consumption.
Galbraith goes into more detail on how to compare and review cards here:
http://www.robgalbraith.com/bins/multi_page.asp?c
The CF standard is beginning to show its age. SD cards are close in capacity, and definitly faster. You also don't have any pins to bend in your camera.
Ahh but some clever people use flash memory for more interesting things like their server's base filesystem. For us this kind of comparison is very useful so that we can see which CF cards are going to give us the best results. Flash-based computing is only going to grow as prices go down and sizes go up. It's fast, small, low power, low heat, quiet, and hard to break. Much better than a hdd for many uses.
At what price learning? At what cost wisdom? The price is a man's peace of mind, and the cost is his life.
if you don't have an end-to-end network. Or if you are dealing with prohibitively large file sizes (more than 512mb usually).
Because my computer(s) at home is(are) connected to the internet, I never need not have access to them. I can freely open up my laptop at the University and access my home resources, much as I can from a University terminal.
Flash media makes sense when you go somewhere where there isn't nice packet switched network joining things, but I haven't run across that yet. The only flash media use I have ever used has been my digital camera, PSP, and iPod Shuffle.
Hell, considering the trivial file sizes involved for most people, they could use that fancy Gmail or (thanks to gmail raising the bar) Yahoo or Hotmail as a virtual storage space, provided they don't mind their files being on servers outside of their direct control.
With scp, sftp, and ssh being how they are, and even how easy it is to email yourself files (and use centralized webmail/imap services such as provided by Gmail or most Universities), it boggles the mind that people would use removable media at all. It's just a 12kb doc file in most cases!
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Flash media makes sense when you go somewhere where there isn't nice packet switched network joining things, but I haven't run across that yet.
I have seen such situations:
Hell, considering the trivial file sizes involved for most people, they could use [free web-based e-mail] as a virtual storage space
You should see the size of "most people"'s MP3 collections. Even a single MP3 is too big for many Internet e-mail servers. And if you limit people to 2 GB, then how can they edit home movies?
The CF standard is beginning to show its age.
CompactFlash is merely another form factor of parallel ATA, meaning that in a pinch or as a boot drive, a CF medium can be connected to a PC's ATA cable through a pin adapter, unlike SD. Free software also supports all features of CF, unlike SD that has built-in support for digital restrictions management.
I'm talking about the common case I see on my campus -- people have small files they want to transfer between school and home (like a document file), which fits into the model of those people the original poster mentioned. This works great with Gmail and Hotmail and Yahoo mail, because all provide very ample temp storage compared to a removeable media device (after all, 2gb of flash is still over 100$ Canadian vs. the free email accounts).
And, of course, when I say "I haven't run across it", I mean I personally have never not been connected. Be it at work or at home, the Internet is right there as another tool in my arsenal. The only jobs I haven't had it handy at were min wage night jobs that support my education. I can come up with plenty of examples that break your little list anyways, as things like Gmail and Hotmail work pretty much everywhere there is http access (even through those persnickety firewalls, or over POTS), and provide that temporary, easy-access storage I mentioned for files of sizes I mentioned. The majority of people live in large economic centres, etc.
Anything over 2 gigabytes is a non-sequitur. Either you're a troll or ignorant for thinking that people regularly go between home and work and want 5gb+ movie files floating around daily via a slow-speed network like the internet, when they could easily use a USB 2.5" or 3.5" external drive (which you would use over flash, since it's about 80x cheaper -- a 160gb external drive + enclosure costs the same as a 2gb external flash device currently).
It's also totally outside the use case me and the original poster were discussing. That is, the problem of small document files that had to move between two locations that were linked by the internet.
My personal anecdote is certainly not a carefully compiled research paper or a full statistics model about a proper pool of people, but it's certainly a plausible situation for most people (vs. using floppy disks, which was probably more prevalent 10 years ago). If you have real studies that show it to not be the case, then it's obvious that education on how to use the internet more effectively is something that needs to be rolled out to those user groups.
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The free wireless internet at the local cafe was down today. The baristas do not know what do when this happens, so it stays down until the right person comes through the rotation.
The network is not always available, or using it imposes some non-trivial costs. For example, at my previous job, I used to do a lot of my most critical work in the morning at a cafe w/o wireless. Yes, I could have gone to another cafe, but this one was right above the train platform at the station where I had to transfer, and I usually really wanted the extra 10 minutes it would have taken to walk to another place. (I also wanted to avoid walking upstream against the morning commute in AM Shibuya). Anyway, I'd copy my stuff to CF and hand it to the staff when I arrived at work. Since I went in early to beat the Tokyo commuting crowds, sending it in by Internet would have meant something like 2hrs less sleep. What's more, most of the staff couldn't figure out email attachments and having an icon which they could double click was a lifesaver.
Of course, sometimes nothing works. These days, I do work for a local university. I'm not a regular employee of the Uni, and I don't have a username and password to get on their network. Usually I send in my results (~100K .doc files converted from LaTeX) by email from home or from a cafe with wireless internet, but sometimes the wireless is down at the cafe or the library is closed and I can't connect. "Aha, well, I'll just copy it to CF with the handy-dandy flash slot on my very small laptop and hand it in at the meeting." Alas, BigProf's Windows 98 can't find the right driver for the USB flash reader. Of course, if I had had an optical drive on my laptop, I could have burned a CD-R on the spot.
I think the moral of the story is that more options are a good thing.
I used that card, and the Apacer PhotoSteno Pro II, and the apacer scored 50% faster in random use, and about 100% faster in linear read/write actions (dd). Luckily I already used the Apacer before, and noticed the huge difference. Since the apacer has a theoretical speed of ~14MB/s, I really can not believe that the standard Sandisk (2003 model) scores this high in the test.
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My point, though, was that many people could be easily using the internet instead of using floppy disks, let alone USB memory keys! If you want to live the most inexpensive lifestyle possible, it's best to save the money you would've spent on the USB memory key. Free Gmail/Hotmail/Yahoo makes this possible even for the least capable people (in terms of having their own servers on a 24/7 fast connection, not intelligence).
Of course, my iPod Shuffle is also a USB memory key. Or, if I have my PSP on me, I simple use my a to b-mini cable and it's another 512mb of portable space that works on any USB mass-storage capable OS (my Linux and my MacOS, but not the Win98 I used in an internet cafe 2 years ago). My cell phone (an N-Gag)e takes the same USB a to b-mini cable and, again, lets me use the MMC card in it just like an ordinary flash memory space. I do have these things, and I'm well aware of their use, I just never use them because the internet's that much easier to use (scping projects between systems).
My University lifestyle (and also my job time, where easy wired internet was available) may not match with your use case, but there are 21,000 people in my city who work or attend my University, and they can easily apply my use case to their lives. Of the remaining 250,000, I'm guessing they could do it too (especially with the open wireless networks everywhere -- any given neigbourhood has 3-4 per block, I've noticed).
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Has anyone done any studies on the lifetime of flash memory?
They have a limited number of times they can be rewritten, and it'd be interesting if someone has ever hooked one up and had a PC repeatedly rewrite a sector until it failed.
That was a great flash-back. A real trip down memory lane.
I remember back when cameras didn't have built-in flash. Cameras for the masses used flash cubes or flash strips. The flash units for SLRs were separate items that attached to the hot shoe.