Ultra Fit USB 3.0: Excessive Heat

My 64GB FIT has run very hot from day 1 when copying files or formating. It is so hot I can’t touch the metal part for more than 2 sec while in use and I have to wait a few min to cool down after pulling it out. While at idle it is just slightly warm. I only use it in a 3.0 port on my  1 year old MSI gaming laptop. It obviously is not a hardware issue since there are so many reported heat problems even in new computers. A design flaw in the Fit has to be the problem . It’s too bad because the size and price per performance can’t be beat but I’d be a fool to trust my data on a drive that is too hot to touch. I will not buy another Ultra Fit at any price although mine is still working fine.

+1. I bought the SanDisk Ultra Fit 128GB USB 3.0 Flash Drive (SDCZ43-128G-G46) from Amazon, drive disconnects when file copied longer than 1 minutes and very hot even when idle.

:cry:

So i just decided to make an account here to post my personal experience and thoughts. I just received the 128GB Ultra Fit from amazon, and am also experiencing some heat issues, although they are only mild so far compared to others. I am running the Fit in a 3.0 port on my macbook pro trying to get a time machine backup. 8GB transferred so far, touching it every minute or so to verify it isn’t about to “melt” and it seems that if you touch it like so, the heat will dissipate into your finger allowing it to stay somewhat normal in regards to temperature. So with that little technique, no issues so far, but will keep monitoring to make sure nothing happens.

Been trying to transfer whole images (5 GB plus) to my fit 128’s, and it throttles back the speed, then the drive winks out. I click continue after a cool down and it will continue.  After 4 times, Windows has had enough and thinks the drive is defective, and I start all over. It’s writing to the drive that makes it hot as it uses heat to write the bits to the chip. With USB 3.0 speed, I can see why. From now on, it’s drives with all metal chassis.

@n7okn wrote:

Been trying to transfer whole images ( 5 GB plus ) to my fit 128’s, and it throttles back the speed, then the drive winks out.

I don’t believe Windows will transfer any single files over 4GB.

http://www.winability.com/why-cant-i-copy-large-files-over-4gb-to-my-usb-flash-drive/

Yea, you’re right, that’s why I format my thumb drives with NTFS.  

I have no way to break up the images, so I have NTFS bootable. Yea… actually made that happen but it wasn’t easy.  I know more heat writing to the thumb drive with NTFS, but no image restore capability without it.  

That’s why I have metal case thumb drives on the way now. Also the thin plastic key chain loop broke on it. That’s my 2nd one. If you keep your Ultra fit on a key chain, you’re asking for it to be put through the wash. That’s what happened to mine.

I don’t believe Windows will transfer any single files over 4GB.

True, but the solution for removable drives is not NTFS, it’s exFAT.  No journaling, less overhead, less heat. And the format the drive comes with.  Did you try transferring your 5GB file before formating the drive?

As for booting a removable drive check out the Easy2Boot app.  http://www.easy2boot.com/

Hi all,

I registerd here just to express that I am completely disappointed by this flash drive.

I was trying to copy a 9GB file to the flash drive - and it kept disconnecting because of overheat after ~7GB of transfer.

After each failure I was waiting for it to cool down. from the 4th try I managed to copy that file, but after I disconnected the drive - it is not detected anymore in OS. So it died completely (I tried several other PCs as well).

Why to manufacture a product which fails its primary purpose - file transfer??

@artci: I completely agree with you. I have been a fan of Sandisk for CF, SD and now USB stick. Sandisk never let me down until this Ultra Fit, which completely changed my impression about Sandisk.

My opinion is, this is a defect product. And after many complaints in this “Sandisk forum”, seems like we are talking to the wall.

Regardless the theory that cramming a high speed chip into a tiny form factor will definitely produce heat, but this fails the main purpose (copying files). If Sandisk cannot produce a decent product in this form factor, they shouldn’t at the first place.

I own both. The Cruzer Fit is still fine, while Ultra Fit is not.

Maybe a campaign against Ultra Fit will draw Sandisk’s attention?

Pretty disgusted with the way you have all been treated. I too had an Ultra Fit - albeit 128gb with the same problems./ Today I exchanged it to a comparable one made by Strontium and it is running fine. 

When will companies realise that the way they deal with customers if things don’t go according to plan (i.e. defective goods) is enough to lose their custom.

I for one will not be buying san disk anymore. 

1 Like

My 64GB FIT has run very hot from day 1 when copying files or formating. It is so hot I can’t touch the metal part for more than 2 sec while in use and I have to wait a few min to cool down after pulling it out. While at idle it is just slightly warm. I only use it in a 3.0 port on my 1 year old MSI gaming laptop. It obviously is not a hardware issue since there are so many reported heat problems even in new computers. A design flaw in the Fit has to be the problem . I’m also getting terrible write speeds of only 23MB/s when it should be around 100 MB/s. My read speeds are better than spec at 145MB/s but that doesn’t make up for the write speed. I will not get any more Ultra Fits at any price, I will try the Extreme 64GB next.

To continue my previous post…

(I wrote this already, but my post got lost, so I’m typing it in Notepad first… yeah, that’s handy).

I contacted SanDisk support about my issue. They assured that the drives were tested for safety and compliance, but they agreed to replace them by another equivalent model. The RMA process took  ~2 weeks and in the end I got my UltraFit drives replaced by 2x full size “SanDisk Ultra USB3 64GB”. They seem to work fine without issues - there is no speed drop and the drive remains barely warm during large file transfers (~10GB).

Despite I was not happy with the product (UltraFit), I admit that SanDisk support was helpful and resolved my issue by replacing the drives with another equivalent model.

Thank you!

PS: certain people with a “Guru” badge here claim that the issues are caused by filesystems or some other mythological reasons. That’s wrong. A storage device should not care what filesystem or OS is used as it should be designed to work correctly under any load providing the ambient environment is within its limits. Please do not confuse people with your silly myths.

@artci: “replace them by another equivalent model”, did you mean they were not replaced with Ultra Fit? Any chance to share what is the repalcement model which works well?

“there is no speed drop”… would you mind to share what is the average write and read speed you can achieve with the replacement model?

Agree with your comments re. filesystems.

I guess enough people have replied… but here’s my reply from experience: Yes the ultra fit does get too hot, but its ok - there’s no problem other than that. Its been working fine for me for the past 1 year with moderate activity. Just some thermal dissipation folks, bear it for the small size :):smileyvery-happy:

@electronicsguy: have you had a chance to see the case of one of the poster here? http://imgur.com/a/sEtdj

I did a small temperature measurement test.

With the ambient temperature around 30’C, the Ultra Fit temperature is as high as 68’C during files were copied into it and the copy process looks like intermittent while the transfer speed dropped to around 18 MB/s (while usually it could reach up to 45 MB/s or higher).

When I put a fan continuously blowing directly to the Ultra Fit (at approx. 8 cm distance), the temperature dropped to 46’C.

I did a small temperature measurement test.

With the ambient temperature around 30’C, the Ultra Fit temperature is as high as 68’C during files were copied into it and the copy process looks like “intermittent” while the transfer speed dropped to around 18 MB/s (while usually it could reach up to 45 MB/s or higher).

When I put a fan continuously blowing directly to the Ultra Fit (at approx. 8 cm distance), the temperature dropped to 46’C.

The temperature was measured with Infrared Thermometer which has 1.5’C accuracy tolerance.

The Ultra Fit specification as stated in Sandisk portal is:

https://www.sandisk.com/home/usb-flash/ultra-fit-usb

Available capacity: 16GB, 32GB, 64GB and 128 GB
Performance/Speed: Up to 130MB/s read; write speeds lower
Dimensions: 19.1 x 15.9 x 8.8 mm; 0.75 x 0.63 x 0.35 in (LxWxH) – without cap
Operating Temperature: 0 C to 45 C
Storage Temperature: -10 C to 70 C
Compatibility: USB 3.0 (backward compatible with USB 2.0)

Does this mean my Ultra Fit temperature during file transfer (WRITE) at 68’C has way surpassed the specified max Operating Temperature (which is 45’C)? Would anyone kind enough to shed-the-light?

@Chin

“did you mean they were not replaced with Ultra Fit? Any chance to share what is the repalcement model which works well?” - SanDisk Ultra USB3 64GB, I did not chose the model, but specifically stated that I do not want a microdrive anymore.

“would you mind to share what is the average write and read speed you can achieve with the replacement model?” - a quick test shown ~100MB/s sequential read and ~50MB/s sequential write. While not great, but it is fine - also the flash drive remains barely warm with a load that killed the UltraFit (copying to flash drive a VHDX disk image of size ~10GB).

I am happy now with the “quality for price” I got with these new drives.

 @chin … well one person doesn’t mean anything. As I’ve said from experience…using it for a year, moderate use. no problems.

@chin how did you measure the ultrafit temperature?