Write Speed Too Slow for Me.
343028
I bought a 128GB Lexar 1000x SD card. I wouldn't have a problem with this product if the write speed was actually advertised. Then I would have not bought it in the first place. In most cases, write speed is of more critical importance than read speed, so why is it not listed anywhere? The card I purchased was put to test in a Blackmagic Video Assist recording DNxHD high-bitrate footage, and it could not perform. Whatever the write speed is, it was lower than what I needed and I experienced dropped frames. By purchasing an equally-priced and accurately-advertised Sandisk Extreme Pro (95R,90W), my problems were solved.

The product functions as advertised.
But that's the problem - it functions as advertised.  Please, Lexar, tell us the write speed of your cards so we know what to buy rather than have to guess!
4024007
This is very nice for the cost but the transfer speed is subpar at best. If you re not using it as an active read write drive you're fine but with these type of applications I've noticed significant lag. Also recalling even text files once I had over 16 gigs worth of storage, was slow.
3175406
A decent microSD card, especially for the price which is unbeatable.  However the write speed on this card is nowhere near the 48mps it claims.  The card i received was particularly slow and only benchmarked at roughly 15mps.  If speed is your goal, pass on this card.  If you're looking for large capacity archival storage for a cheap price, this is your card.
3537933
I clocked write speed at about 14 MB/second on windows XP. That's nice. On the downside, it has this incredibly irritating red light that slowly blinks even when the drive is idle! I was ready to take a hammer to the thing until I put black tape around it to hide the light. Now I can't see the light flash when data is read written or read to the drive. Also, it's bulky enough to bump into other USB devices, so you may need to remove them. I did not have either of these problems with my old Memorex 512MB traveldrive, which was only slightly slower.
204782
I typically do not review products, but this one is a bit of a special case for me; the read and write speeds are horribly misadvertised, as I'm getting less than half of the advertised 'up to 100 mb/s'. Then again, it was "Up to", meaning that sandisk could lie and weasel their way out of a disappointing product.

The reason I'm giving this 2 stars, even with my disappointment, is that it at least works for what I want, at least, so far.
965679
I have always liked Transcend flash memory products and the comfort of physical durability made for high expectations of this external USB 2.0 drive.
The style and external build quality impressed. However, the write times for this drive are woefully slow.  I have several portable drives from LaCie (Samsung HD), Iomega and Seagate and they are all at least x4 faster.  I formatted on a 10.6 Apple laptop (HFS journaled and FAT32) and a Win7 Compaq desktop (FAT32 and NTFS) with similar results. Read times are acceptable.

I use the drive to transfer bunches of small files (JPEGs, MP3, documents); my plan of using it for a backup drive had to be scrapped. On the plus side, the drive works fine with just one USB port on my MacBook Pro (2007) and Asus netbook.

*UPDATE 2/23/11*

Remembering that the drive has a two-year warranty I sent the drive to Transcend USA (Orange, CA) and about one week later received a brand-new drive in the mail. No explanation was given for the swap but the replacement drive seems to work fine and am pleased with Transcend's quick service. It's nice to be able to power this drive from one USB port from my silver-keyed MacBook Pro.
1384757
Really terrible performance - my older USB 2.0 flash drives are faster than this model. I contacted Kingston to inquire about the speed and was told that the 5MB/sec write speed was "in line" with what's considered normal for this model, and if I wanted faster write speeds I should select a different model. If you want speed/throughput, STAY AWAY.

I've tried these on several Mac models as well as a PC running Linux - same across the board.

Oh yeah, and sometimes it takes FOREVER for them to unmount. Another thrill.
4547007
Not sure if there is a quality control problem, but as with other customers, I can only get a write speed max of around 19 MB/s. I use it in a canon 7d and 5d (with adapters) and this SD card was slower than my old 133X CF cards. I later got a&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/PNY-U3-Turbo-Performance-64GB-High-Speed-MicroSDXC-Class-10-UHS-I-up-to-90MB-sec-Flash-Card-P-SDUX64U390G-GE/dp/B00W77C1QU/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">PNY U3 Turbo Performance 64GB High Speed MicroSDXC Class 10 UHS-I, up to 90MB/sec Flash Card (P-SDUX64U390G-GE)</a>&nbsp;(also used with the same adapter, but also a micro adapter on top of it) and it wrote at least 2 times quicker. You may luck out and get an sd card that runs as advertised, but I suggest waiting until the micro card goes on sale (commonly under $20 for a 64 GB) and get an adapter. I've bought 3 of the micro sd cards, and they have all been as fast as advertised, or faster.
556165
Very slow transfers when transferring multiple files over USB 2.0, even when compared to a USB 2.0 data stick rated at a much slower read/write speed.
2381721
Using SanDisk Extreme Pro 64 Gig.

http://www.amazon.com/SanDisk-Extreme-Memory-Speeds-Ready-SDSDQXP-064G-G46A/dp/B00NUB3530?ie=UTF8&psc=1&redirect=true&ref_=oh_aui_detailpage_o09_s00

Getting consistent read speeds in the mid 90's and write speeds of 70 MBs.
4753380
256gig model is much slower than other cards I have been using recently, which are typically rated at 95 read 60 write.  I regret the purchase and not sure what I will do with it.  However it does have 256 gig, and seems to work fine.
4464549
Is it just me or is it really that slow? Had a SanDisk 64G USB3.0 earlier it was markedly fast (though overheated on occasions).
2049180
Speeds seem slow, although the extra storage is nice.  Probably would upgrade to a faster transfer speed if I had known how slow this one is.
2841202
I bought one of these at our school bookstore last week (which had *boxes* of them) and have had nothing but problems with it.  I wanted to use this to transfer files between my desktop (WinXP) and laptop (Leopard) but when I move more then 100 megs at a time, it tells me I don't have permission and the transfer freezes.  It won't let me eject or shut down (because it thinks it's still copying) so I have to pull the drive out and relaunch Finder.  Basically, I'm using an 8gig drive to move less than 100 megs at a time.  I can do that much more effectively with my old 1 gig.

Just taking its ability to work with WinXP into consideration, I'd give it a higher rating if the transfer speed wasn't so inconsistent and slow. Nothing against Kingston though.  They're still my favorite RAM manufacturer but they failed on this one.
4968774
Bench-marking this against a Patriot USB 2.0 small key usb drive, I find that the write speeds are kind of poor on the corsair. I tested with 2.73 Gb of data (148 files ranging from small to medium size).

I got 4:04 with the USB2 Patriot vs. this drive at 3:30 for WRITE speeds. Improvement of only 15%.

Reading the same folder back to my PC saw the biggest difference where the old 2.0 Patriot was 2:39 vs. the this Corsair drives time of 1:22 for READ, improving almost by 100%.

But it is WAY too bad the write speeds are not better!! This has little to do with USB 2.0 vs. USB 3, but rather the not-so-great quality of the flash memory in this thumb drive. You find this kind of slow to read speeds on cheap flash memory.

The rubber key ring mount seems like it won't last terribly long, but time will tell. It stretches easily, and that I fear will lead to it snapping/tearing at some point when it snags on something in my pocket. I appreciate the 32Gb space and the read speeds, but I wanted a drive I could write to faster, and this is only giving me barely a 15% speed increase, and that is why I've knocked it down to 3 stars.

Update: to be fair I'm not sure how fast these really small USB keys get. I'll be trying another one soon and comparing.

It's basically OK, but I'm disappointed. I would keep looking if I were you. I will likely return this for another brand, even though the price was not bad.
4752794
Nursing outline goodHowever the write speed for this "USB 3.0" Flash Drive is quite slow. It is only around 30Mb/s
757591
Read rates at 4 mb/s on USB 3.0 line and from fast HDD, while lower spec'd PNY got 40 mb/s with same files.  Write to HDD gradually worked up to about 140 mb/s, but still assume it's a fake or defective.  Probably why it got returned and ended up in the Warehouse.