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My 2GB dane-elec USB thumb drive is much slower in reading (and writing) data than a USB external hard disk. The hard disk is about 6 times faster. Is this normal? And if so, what is the reason that USB thumb drive is so slow while SSD drives are faster than hard disks?

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Low-end flash memory (most USB thumb drives and SD cards) only do a few random writes per second. Mechanical hard drives can do about a hundred. If you write a large number of small files you'll see a huge difference. – netvope Oct 23 '11 at 17:54
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This is normal, sort of. It all depends on the type of memory inside. USB flash drives are fast and really great at small file transfers. However, when you say "External USB drive", I take it as a is basically a Regular Hard drive connected via USB in an external enclusure. These types of traditional hard drives are slower than flash for small files, but as the file size increases, so does the appearance of speed: they can write more bulk data than a cheap USB Flash Drive.

Also, you should make ure that your cheapo Usb flash drive is actually USB 2.0 compatible. If its not, then USB 1.1 is wayyyy slower.

As far as SSD vs USB Flash drives, well its whats inside that counts. You can acutally get USB flash drives which are very fast.

Take a look at this article for a starting point..

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Just curious, how slower is USB 1.1? I read somewhere that 1.1 means its transfer speed is 11MB/sec and 2.0 means 20MB/sec but I highly doubt if that's true or not. – kai Sep 9 '09 at 17:13
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Just to be clear, my drive is definitely USB 2.0... – Dani van der Meer Sep 9 '09 at 17:16
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@kai: Much bigger difference. From everythingusb.com: USB 2.0 has a raw data rate at 480Mbps, and it is rated 40 times faster than its predecessor interface, USB 1.1, which tops at 12Mbps – Will Eddins Sep 9 '09 at 17:40
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USB 1.1 is rated at 12 Mega*bit* per second, which is equivalent to be about 1 megaBYTE per second. USB 2.0 is oh, just about 40 times faster, rated at 480 Mega*bit* per second, which translates to be about 40 megaBYTES per second. – caliban Sep 9 '09 at 17:42
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Also, note that Mbps is MegaBITS per second, which means USB 1.1's max speed is around 1.5MB/s – Will Eddins Sep 9 '09 at 17:42
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up vote 2 down vote

EDIT : since everybody is saying the same thing, might as well i have some fun and say something different

What a question - so you expect small, shock-resistant, cheap... AND fast too??

The reason why USB drives are slower than mechanical hard drives and SSDs is simple - the manufacturers made them that way because it's a mass consumers product. And of all the feature-set, fast is the least appreciated by average consumers (they are not going to notice their single Excel document copied over 0.1 secs faster), and the most expensive to implement.

So, what do you think the manufacturers sacrificed? :)

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I am not sure I agree with the cheap part. The price per gigabyte is much higher than a mechanical hard disk. But I suppose you have a point, I probably expect too much :) – Dani van der Meer Sep 9 '09 at 19:45
we all expect too much but get too little. That's why we come onto SuperUser.com to grumble. :P – caliban Sep 9 '09 at 19:47
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up vote 1 down vote

while SSD drives are faster than hard disks

This is not necessarily true. They are much faster at randomly scattered small reads (which regular HDs are very, very, very bad at, since they involve waiting for mechanical parts to move before you can even start reading). But they are usually considerably slower at writing (since you have to erase flash memory before you can overwrite it) and even large bulk reading (which HDs excel at).

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And don't forget that mechanical disks have cache onboard so they may only have to read those small files once. – Joel Coehoorn Sep 9 '09 at 16:51
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correct. +1 – Molly7244 Sep 9 '09 at 16:59
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Depends on which SSD you are talking about. There are some SSDs that beat HDDs even at writing and sequential reads, they just cost a bit more than the bargain SSDs. There are even some that are 100x as fast as HDDs, you just pay thru the nose for them. – davr Sep 9 '09 at 17:15
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These benchmarks, cdfreaks.com/review/18164-ocz-agility-120gb-ssd-review/…, show an SSD almost twice as fast as mechanical in sequential write. They may not have the insane lead as they do in reads, but I wouldn't call that "considerably slower". – hyperslug Sep 9 '09 at 17:39
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Quality of hardware components / IC

I have a very very fast USB flash drive that is just as fast as SSDs but cost a lot of money.

Whilst it isn't always the case that "You get what you pay for", sometimes it is!

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up vote 0 down vote

Quality of parts and controller.

This Wiki quote sums it up nicely.

The fastest drives currently available use a dual channel controller, although they still fall considerably short of the transfer rate possible from a current generation hard disk, or the maximum high speed USB throughput.

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