Hi, after reading several favourable reviews for the above drive, I decided to purchase a couple. I noticed immediately that I was getting nowhere near the quoted performance.
Reading seems to cap-out at about 35MB/s and writing is even worse at about 25MB/s.
I have a Samsung SSD in my laptop and I am using the usb3 port.
Both drives are showing the same figures.
Is there something obvious I am missing here ? The usb3 controller appears in windows device manager and appears to be working Ok.
This USB 3.0 drive is not (at all) as the manufacturer describes in term of speed, its maximum speed (The so-called Up To) is actually 41 MB/s for read/write, NOT 245 MB/s / 190MB/s.
Just thought I’d post a reply which I wasn’t expecting to ! I’ve sorted the problem out in a way I can only say that I was surprised about.
I had tried everything I can think of, checking controller drivers, bios settings etc etc and the only thing left was for me to reinstall windows which wasn’t a problem as I was doing this on a new pc I had just built. The problem still materialised
I was about to contect sandisk when my mate (who is a techie at the local university) popped in forra visit. After explaining my problem to him, he decided to have a look at my pc and found that the windows installer I was using was in fact corrupted and although everything visually appeared to be OK, the W7 Enterprise install was in fact faulty.
Once he sorted out my Installer and got the O/S on my machine again, the pen was working at speeds I expected
Now unfortunately, the things he checked were beyond my skills so I can’t say exactly how he found out that I was installing a corrupt version but I just thought it prudent to mention it here so that a, people may have another option to check before they rma their device and b, this thread can be locked by the mods if they so desire.
All people, sometimes solve problems by luck not by skill/experience/sense, this mostly because they don’t have time or can’t reproduce the main reason of the problem.
Any way I’m glad you solved your problem, Although its funny that you say Windows Installer, has something to do with it.
Actually I don’t think Sandisk sells products, they manufacture them and stores and merchants sell their products, and products that look like Sandisk’s.
SanDisk’s technical-support are actually offering replacement for my 64GB model, and promised it will be as the advertised speed…
but my main problem is in the shipment (Egypt <–> USA), I can’t afford it 2 more times.
I shouldn’t buy it from a remote country (using Amazon).
My SanDisk ExtremePro 128Gb have this problem too after a time use it (1 moth), Speed only around 40MB/s (by DiskMark and HDTune), i tested on 2 PCs, sure with USB 3.0 port, both Windows 10 and 8.1 installed on SSD.
My SanDisk ExtremePro USB3.0 128Gb have this problem too after a time use it (1 moth), Speed only around 40MB/s (by DiskMark and HDTune), i tested on 2 PCs, sure with USB 3.0 port, both Windows 10 and 8.1 installed on SSD. Have tried SLOW FORMAT option but no change !
SanDisk are liars, don’t try any suggested configurations (even from the company themselves), your only hope is to return it or replace it with other product, if the merchant is near you.
My SanDisk ExtremePro USB3.0 128Gb have this problem too after a time use it (1 moth), Speed only around 40MB/s (by DiskMark and HDTune), i tested on 2 PCs, sure with USB 3.0 port, both Windows 10 and 8.1 installed on SSD. Have tried SLOW FORMAT option but no change !
SanDisk are liars, don’t try any suggested configurations (even from the company themselves), your only hope is to return it or replace it with other product, if the merchant is near you.
Edit: I found a solution.
I just mounted the usb disk to a different USB 3.0 port (I have 2 only), and it worked better than the old 40 MB/s.
So, anyone has this problem, just try all the USB 3.0 ports in your PC/Laptop.
I was about to return my Sandisk Extreme 64 GB because of the same slow speed issues, when I stumbled upon a solution to restore the original writing speeds.Â
Basically, as some other users have stated, this flash drive is a SSD on a stick, with no TRIM support. Therefore, if the flash drive is formatted ONLY ONCE, the speed levels will decrease due to FAT corruption. This is a MAJOR problem of this flashdrive if you plan to format it in the future. Sandisk’s official word is “DO NOT FORMAT” , but I think it is preposterous.
“Why is it a major problem?”, you may ask. Well, for those users who want to have a high-speed USB stick with no problems, the solution is not simple. The flash drive requires a deep format such as an ATA Secure Erase, which basically flashes all the clusters at once and restores the original status of the flash drive. A Linux distro that might come handy is Parted Magic (https://partedmagic.com),,) which includes many features to tinker with partitions, different kind of secure erasing systems and such. By booting your computer into Parted Magic using a Live CD/USB, you can ATA Secure Erase the Sandisk Extreme to bring it back to its high speed days. My flash drive went from 10 MB/s to 200 MB/s of writing speeds after following this procedure.
Word of caution: be careful what you do with Parted Magic. You can render your internal HDD and/or your USB flash drive useless (“bricked”). Do your search first and make sure you follow the tutorials in case of doubt. Or keep filing RMAs with Sandisk until you are satisfied. I have read about costumers who have returned up to 5 Sandisk Extremes due to this issue.
Another thing: do not try running Parted Magic on a Virtual Machine. By default, Parted Magic does not allow you to ATA Secure Erase USB-connected drives. If your internal HDD is not detected, it wil not allow you to open the ATA Secure Erase app at all. Once you boot into PM, it will detect your HDD and then you can proceed to NAND wipe your flash drive at your own risk.
Good luck and hope that my post can help someone…
