USB Stick Challenge - Recommendation in last posting

[admin]

To verify if a certain type of USB stick can handle the needed write/erase cycles I designed a Linux test program to find out how many cycles it can handle.

The test program writes a 64kB block of generated random data 10.000 times onto one single position on the stick and checks after each write if the data is stored correctly. When a 10.000 write cycle has passed all other cells on the stick are also checked, if they did loose their information which can happen as a side effect. This goes on until the stick throws errors. Yes, this destroyes the stick, but we gain some better understanding what sticks handle wear leveling well and which do not

Endurance will be measured by "rounds". A "round" is defined as how often the whole stick could have been completely filled by the written data volume (until the error occured). This takes a stick's size (which helps in doing wear leveling) into account and can give a size independent measure for endurance.

A heavy working Meteohub system uploading lots of graphs, feeding many weather networks is expected to produce a load of about 2 "rounds" per day. Newest Meteohub versions do display a accumulated round value since last reboot on "System Info" page. When you devide that value by the number of days the system is online you get the average "rounds" per day. In the attached example this is about 2 "rounds" per day. When you have a good storage like JetFlash130 in use, which can stand over 2000 rounds you can expect at least 3 years of untroubled operation. In reality I would expect more than the double of this, because the stress test by writing over and over data to one and the same blocks for a hundered of million times is much more demanding than what happens in real life.

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I will post findings about no name and major brand sticks in this thread...

[admin]

This no-name "Platinum" stick, 2GB, failed after 5.5 million 64KB writes onto the same position. Taking its total size of 2GB and a write block size of 64kB into account the stick had only handled 172 "rounds".

The stick does not generally shutdown writes now, so in normal operation the stick would lead to a disrupted file system with high propability of data loss.

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[admin]

This Transcend JetFlash 620 8GB stick, failed after 13.5 million 64KB writes onto the same position. Taking its total size of 8GB and a write block size of 64kB into account the stick had only handled 105 "rounds", which is not too good.

A good feature of the stick is, that it does not take any writes any more, which means it has froozen its status. In a real world scenario it would skip to a read-only filesystem, which allows you to copy the content to a new media without loss of recorded data but with a down time of the system.

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The stick is medium fast (5-6 MB/s write speed), medium priced, wears out rapidly but behavecs nice when being worn out.

[admin]

This Transcend JetFlash V33 4GB stick, failed after 8 million 64KB writes onto the same position. Taking its total size of 4GB and a write block size of 64kB into account the stick had only handled 124 "rounds", which is not too good.

Error occurs as crosstalk on a neighbouring flash cell, which seems to be permanently broken as it does not take any new values to store. Unfortunately, this Transcend stick doesn't shut down writing completely (like the 620er) to conserve the data but simply does not store new data on a block without sending any error message.

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The stick is slow (< 3 MB/s write speed), cheap, wears out rapidly and does not behave nicely when being worn out.

[admin]

This Transcend JetFlash130 4GB stick, failed after 130 million 64KB writes onto the same position. Taking its total size of 4GB and a write block size of 64kB into account the stick had handled slightly over 2000 "rounds", which can be regarded good.

Error occurs on writing the block. Once the error occurs the stick does not perform any more writes to any block. This is regarded as well behavior. A logical drive on top of the srick will fall into "read-only" mode. This will abort operation, but data stored so far will be ok and not corrupted by creeping data loss, while other parts of the stick do still look like working fine.

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The stick is fast (> 10 MB/s write speed) and reliable but unfortunately hard to get and pricy. Once it wears out, it behaves nicely. I do recommend the Transcend JetFlash130 4GB for Meteohub use.

[admin]

This Transcend JetFlash560 4GB stick failed after 93 million 64KB writes onto the same position. Taking its total size of 4GB and a write block size of 64kB into account the stick had handled 1440 "rounds", which is not bad.

Errors occure in a mixture of failing writes and crosstalk to neighbouring blocks. It does not report errors on that, data gets corrupted silently, which is not a very nice behavior in case of being worn out.

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The stick is not very fast (4 MB/s), medium priced, but has quite a good reliability in handling tons of writes.

[admin]

The Super-Talent Pico 4GB stick, which is small and covered in stainless steel handled 86 million 64KB writes onto the same position. Taking its total size of 4GB and a write block size of 64kB into account the stick had handled 1330 "rounds", which is not bad.

Error occured as reported read errors on a large range of blocks. I doubt that this would not be recognized by the system, but being there you also don't have further access to a large area of the stick, which is not good.

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The stick is rather slow (3 - 4 MB/s), medium priced, has quite good reliability in handling tons of writes, but more or less completely inhibits reading data, when being worn out.

[admin]

The Intenso 8GB USB3 stick, which comes in a not so big housing which feels like black metal, handled disappointing 2.6 million 64KB writes onto the same position. Taking its total size of 8GB and a write block size of 64kB into account the stick had handled only 20 "rounds", which is extremely bad.

Error occured as reported read errors on a large range of blocks. I doubt that this would not be recognized by the system, but being there you also don't have further access to a large area of the stick, which is not good.

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The stick is rather slow (5 MB/s) when writing small chunks, medium priced for a USB 3.0 stick, but can't handle lots of writes and more or less completely inhibits reading data, when being worn out.

[admin]

This Transcend JetFlash700 4GB stick failed after 11 million 64KB writes onto the same position. Taking its total size of 4GB and a write block size of 64kB into account the stick had handled onls 170 "rounds", which is bad.

The errors occure by no logner allowing any reads from the stick, which will make the problem eminent to the user at once but also renders all data as no loger available on the stick, which is no nice behavior.

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The stick is pritty very fast (13 MB/s write speed), medium priced, but not a good level of reliability in handling tons of writes.

[admin]

An exceptional poor performer is the OCZ Rally 2 8GB stick. It just mastered 180.000 writes onto the same position before failing. Looks very much like no wear leveling has been implemented at all. Write speed was just 1.5 MB/s when treated with 64k writes. Keep away from this one.

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[admin]

Another not so reliabe stick is the Super-Talent Express DUO 8GB which only handled 6 million writes of 64k blocks onto the same position until it fails. This means it took just 90 rounds before it fails. Failure blocks any further reads from the stick, so you don't get you data back from it. Write speed is quite good at 9 MB/s when writing small blocks.

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[admin]

We have a clear winner. The Patriot Xporter Boost XT with 4GB capacity took over 150 million writes which is equal to about 2300 rounds and still works fine. This is exceptional endurance. Read speed is at 25 MB/s and writes are at 8 MB/s, which is not bad for a cheap stick.

This stick gets my recommendation to be used with the iConnect. Please keep away from the variants with higher capacity, as iConnect will not be able to boot from these!

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