USB flash drives x many = SSD?

This is a discussion on USB flash drives x many = SSD? within the Tech Board forums, part of the Community Boards category; Get S.M.A.R.T....

  1. #16
    (?<!re)tired Mario F.'s Avatar
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    Get S.M.A.R.T.
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    Originally Posted by brewbuck:
    Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.

  2. #17
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    Get S.M.A.R.T.
    Sure. Never really used it myself, so don't know how it performs.

    But how about a drive that doesn't fail? It's certainly a lot more common to hear platter drives fail than SSDs (including USB flash drives, in case you want to say that's because no one uses SSDs yet )

  3. #18
    (?<!re)tired Mario F.'s Avatar
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    Well... SSDs are far more unreliable than HDDs, being considerably more susceptible to magnetic and electric fields, a condition you can't predict. They can only serve reliably as temporary storage devices. To make matters worse, the more interesting DRAM SSDs are vulnerable to power outages.

    Still, it's no surprise this thread will become obsolete in... I don't know, a couple of years at most? These things just tend to drop in prices abruptly as soon as they get mass adopted; a real possibility now that even my 50 Euro trash printer comes equipped with an SSD slot.
    The programmer’s wife tells him: “Run to the store and pick up a loaf of bread. If they have eggs, get a dozen.”
    The programmer comes home with 12 loaves of bread.


    Originally Posted by brewbuck:
    Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.

  4. #19
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    Well... SSDs are far more unreliable than HDDs, being considerably more susceptible to magnetic and electric fields, a condition you can't predict. They can only serve reliably as temporary storage devices. To make matters worse, the more interesting DRAM SSDs are vulnerable to power outages.
    Hmm. I thought HDDs are susceptible to magnetic fields, too. I will try to fill my SSD ipod (nano) up with random data, md5sum it, play with a magnet around it, and md5sum it again to see if data corruption has occured. You want to try that with your harddrive? (yes, I am serious, as long as I can be assured that it won't cause permanent damage. I am a very scientific person and like to experiment with everything ).

  5. #20
    (?<!re)tired Mario F.'s Avatar
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    No need to test. Modern hard drives are enclosed within a special cage which does protect them from anything except the strongest fields.

    The movies lie
    The programmer’s wife tells him: “Run to the store and pick up a loaf of bread. If they have eggs, get a dozen.”
    The programmer comes home with 12 loaves of bread.


    Originally Posted by brewbuck:
    Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.

  6. #21
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    Based on my 5mins of reading on Google, SSDs are not susceptible to magnetic fields like harddrives, except in one instance - when the magnetic field induces a current big enough to fry the circuit. But for that to happen, you need a very big flux/s. Meaning (assuming you are not a physics person. sorry for the ignorance otherwise), the magnetic field has to change very fast. For example, if you put it in a high-powered coil and run 220V alternating current through it. That, I don't think is possible in day to day usage . A strong field alone, no matter how strong, will not affect a SSD.

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    hmm seems everything reasonable so far, but you're all forgetting the biggest draw-back of SSD's:
    due to abrasive wear, you can only modify each cell about 100.000 times. This may sound ok, but if you remember, that the swap partition (or pagefile.sys for Windows) is changed continuously, this is actually a lot.
    Though linux users can use JFFS2, because it makes sure, that the cell-usage is evenly distributed, increasing the lifetime.

    No matter what, I think SSD's are not technically mature yet and not worth their current price. The idea of using 4 usb flash drives with RAID0 is clever, but most Laptop users don't have 4 spare usb ports. and even the power consumtion may be equal to a 2.5" platter hdd (Just checked, mine consumes ~1.5W at startup). Besides the fact that my laptop just has 1 usb port, how weird would it look with 4 usb sticks? ;D

  8. #23
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    Current SSD technology allows reads/writes to be spread out over several cells instead of just being focused on one cell, increasing the lifetime of the cells.
    If there's a 100 000 cells and they can be read/written 100 000 times, you could theoretically do 100 000 * 100 000 reads/writes, which is a lot.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  9. #24
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    Still, thats the write limit is probably the biggest concern I have about SSHDs. Especially when you have a computer where the operating system is on it with logging, swapping and stuff.

  10. #25
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    Quote Originally Posted by Elysia View Post
    Current SSD technology allows reads/writes to be spread out over several cells instead of just being focused on one cell, increasing the lifetime of the cells.
    If there's a 100 000 cells and they can be read/written 100 000 times, you could theoretically do 100 000 * 100 000 reads/writes, which is a lot.
    afaik 1 cell represents 1 bit (bridge open or bridge closed). Which means that 100.000 state changes are very little. Creating a file with the contents "Hello" would already be 40 changes, twice as much if its unicode. and there are additional changes for the file-system pointers...

    Let's talk again about that topic in a few years. SSD's might be worth the money by then
    Speaking about laptops and their battery lifetime, it's cheaper to buy another battery than the few mW you save from the SSD.

  11. #26
    (?<!re)tired Mario F.'s Avatar
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    Looking at the information provided by wikipedia on SSDs, the disadvantages seem to be important when compared to HDDs. Currently using these devices as random storage seems counter-intuitive since HDDs provide more data at a lower cost, using less space and with a considerable larger lifetime.

    Now, I can see them as a second device for temporary or backup storage. The lower write access, the (I insist) lesser reliability, and limited writes, when compared to HDDs, still beat DVDs and CDs.
    The programmer’s wife tells him: “Run to the store and pick up a loaf of bread. If they have eggs, get a dozen.”
    The programmer comes home with 12 loaves of bread.


    Originally Posted by brewbuck:
    Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.

  12. #27
    C++まいる!Cをこわせ! Elysia's Avatar
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    Although prices for SSD is dropping rapidly.
    In a few years, they'll catch up to HDDs, and pass them, from what I saw in an article once.
    Well, I'm guessing SSD will be more reliable by then. It's an area of intense researching, after all.
    Quote Originally Posted by Adak View Post
    io.h certainly IS included in some modern compilers. It is no longer part of the standard for C, but it is nevertheless, included in the very latest Pelles C versions.
    Quote Originally Posted by Salem View Post
    You mean it's included as a crutch to help ancient programmers limp along without them having to relearn too much.

    Outside of your DOS world, your header file is meaningless.

  13. #28
    (?<!re)tired Mario F.'s Avatar
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    I agree. They are only now hitting the road.
    The programmer’s wife tells him: “Run to the store and pick up a loaf of bread. If they have eggs, get a dozen.”
    The programmer comes home with 12 loaves of bread.


    Originally Posted by brewbuck:
    Reimplementing a large system in another language to get a 25% performance boost is nonsense. It would be cheaper to just get a computer which is 25% faster.

  14. #29
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    No matter what, I think SSD's are not technically mature yet and not worth their current price. The idea of using 4 usb flash drives with RAID0 is clever, but most Laptop users don't have 4 spare usb ports. and even the power consumtion may be equal to a 2.5" platter hdd (Just checked, mine consumes ~1.5W at startup). Besides the fact that my laptop just has 1 usb port, how weird would it look with 4 usb sticks? ;D
    Well, you can always get usb hubs . IIRC one USB bus can do 60mb/s (480Mbit/s), so it may not be a good idea to connect all 4 sticks to the same hub (unless you don't mind maximum 60mb/s throughput). I would connect 2 to one bus (and use two ports). Most laptops nowadays have at least two USB ports .

    Oh and I read somewhere that, in agreement with Elysia, nowadays USB flash drive firmwares do wear-leveling (used to be the filesystem's job).

    The lower write access
    The particular example I have given has a write speed of 64MB/s. IIRC that is on par with if not faster than current 2.5" laptop harddrives (average ones). The read speed of 132MB/s is faster than any harddrive I have seen (consumer harddrives). Certainly faster than laptop drives.

    the (I insist) lesser reliability
    That I am not so sure (literally. I haven't done much research in that area).

    and limited writes
    With wear levelling implemented in firmware, is it really that bad? also, swap may not be needed at all depending on amount of RAM. My desktop with 2GB of ram doesn't have any swap file/partition. IIRC, even if you create one, Linux won't touch it until it runs out of DRAM, which has never happened in the past year or so that I have been running my computer without swap.

  15. #30
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    Quote Originally Posted by cyberfish View Post
    Well, you can always get usb hubs . IIRC one USB bus can do 60mb/s (480Mbit/s), so it may not be a good idea to connect all 4 sticks to the same hub (unless you don't mind maximum 60mb/s throughput). I would connect 2 to one bus (and use two ports). Most laptops nowadays have at least two USB ports .

    Oh and I read somewhere that, in agreement with Elysia, nowadays USB flash drive firmwares do wear-leveling (used to be the filesystem's job).


    The particular example I have given has a write speed of 64MB/s. IIRC that is on par with if not faster than current 2.5" laptop harddrives (average ones). The read speed of 132MB/s is faster than any harddrive I have seen (consumer harddrives). Certainly faster than laptop drives.


    That I am not so sure (literally. I haven't done much research in that area).


    With wear levelling implemented in firmware, is it really that bad? also, swap may not be needed at all depending on amount of RAM. My desktop with 2GB of ram doesn't have any swap file/partition. IIRC, even if you create one, Linux won't touch it until it runs out of DRAM, which has never happened in the past year or so that I have been running my computer without swap.
    yes, an usb hub is a solution, but... you can't feed 4 usb flash drives with one usb port. The power output is way too low. Yes, anyone else could use a second usb port, but in my case this is not possible.. The Thinkpad 600E only has one usb port (its from Feb. 1999.. heh). But you're right, modern laptops can handle this, I'm the exception
    I guess with a little craftsmanship it should even be possible to build a nice case for two or even four usb drives...
    hehe, this kind of motivates me to build a case for the drives, including some source of external power (to work them with one usb port). I think an acrylic casing would be awesome... maybe I'll build the case before buying the drives. I think I even have acrylic somewhere

    erm wait a second.. this idea just became obsolete. They have 32G usb flash drives at alternate.de for just 92 EUR.

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