Why is it so hard to find tech specs on actuall transfer rates for Thumb Drives? Everyone Claims "High Performance" "The Fastest" etc, etc. Also, I found if you run across these types of numbers in speed references 150x, 200x, etc. Those speed ratings are based on the original rotational speed of a CD player; 1X delivers 150 kiloBytes per second.
Heyy, these are really good info. but remember, most of the times, what manufacturers specify are not 100% correct. I have found some benchmarks on flash drives and did a small comparition. The Corsair Vayager GT and Patriot Xparter XT came really close. Take a minute and read it, And please comment your data too.
I believe that USB 2.0 actually has about 34 to 36 MB a sec of bandwidth. So there is going to be a bottle neck at some point no matter how fast the drive actually is. I also believe what xcorat says about vendor specs not being accurate. Some might be conservative while others might be optimistic. I have about 30+ flash drives, some new some old, and the fastest one I have ever seen is the Turbo series from Sony. It is rated at 28mb a sec read and 18mb a sec write. I actually tested it at mid 30s for read and low 20s for write.
well, I read somwhr about a USB HDD that can read at 40MB/s. And the max USB2.0 can go, theoritically is 48MBps.(480Mbps / (8 data bits + 2 parity bits)
(isnt it??) so I guess we will be seeing USB drives that can go up to about 40MBps. But remember USB3.0 spec is supposed to be released this year, Which they boast to have 3Gbps throughput. probably in a couple more years, they will be really fast (somwhr around 300MBps!!!!!!) and will come packaged with hand gloves..............!!!! (well, wont they be blazing hot as well????).................lol
Btw, rozar, why dont you submit some benchmark scores to on my page, so I can add those too. Use HDTune http://www.hdtune.com/
Message edited by xcorat on 05-27-2008 at 08:58:54 AM
Yeah USB 2.0 is spec to 480mbps but I dont think it is really that fast in real world use. Im not sure what the reason is and maybe someone can fill us in. But also we know that a 1 gbps network connection never really goes that fast either.
I will see if I can post some results sometime.
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Reply to rozar
Also, the usb 2.0 spec 480Mbps is the peak transfer rate. The average transfer rate is much lower, which is why even Firewire 400 can beat usb 2.0 on transferring large amounts of data, and probably why the highest speeds on flash drive are all around the upper 30's.
The THEORETICAL bandwidth of the USB 2.0 specification is 480Mbps which comes out to be 60MBps. Every type of bus and or device will have a theoretical bandwidth speed but various real-world considerations will generally keep the actual effective throughput much lower.
lol, all of you havent heard of Buffalo technology's Flash drives have you..? Buffalo still uses the SLC NAND flash chips!
Reads @ 39mb/sec Writes @ 32mb/sec
its not available anymore in the us its time we all asked buffalo to start importing these from Japan!
check the buffalo Japan Website and translate using google.. you will be surprised!
it owns! all the competetion..
Its time these companies stopped using MLC NAND calling them the fastest flash chips.
SLC nand uses a simple logic and has a longer lifespan.. its just a tad costiler.. but for people who want performance.. its small price to pay.
The System always reserves some USB bandwidth for it's use. For Windows look here:
Device Manager (devmgmt.msc)
Universal Serial Bus Controllers, untree this (click the plus sign)
Select any of the "Blah blah blah USB Universal Host Controller / USB2 Enhanced Host Controller"
Right Click > Properties
Advanced Tab (at the top)
Most systems today reserve 10% of the bandwidth
I have not seen it documented that there are 2 parity bits per byte of data, and assuming there is none then:
480 megabits per second / 8 bits per byte = 60 Megabytes per second, with 10% reserved = 54 Megabytes per second.
I don't believe the Universal Serial Bus uses any type of parity, or error correction. The majority of main memory isn't even ECC (Error Correcting Code), why would they waste that much bandwidth on parity for the USB?