New Extreme 64GB (SDCZ80-064G-G46) is only 62GB ???


I’ve received a stick few days ago and specs are not 64GB as it should but only 62GB.

Also, read speed is not ~245 but more around 195MB/s (desktop Z87 motherboard with usb driver).

See correct one from another customer:

Correct key

And see mine :

faulty stick ?

See “normal” stick transfert rate (on HM77 chipset oO) :

normal transfert rate

And the see my stick transfert rates :

my transfert rates

Why could i have received a different product ???

pSSD 62.7GB with firmware 3 vs SSD U100 64GB with firmware KM.10.00

I would really appreciate an official answer, i can’t understand why sandisk doesn’t communicate on this, as they know what they sell.

Another customer got same product on amazon :

I’ve ordered mine at—Inkl.-SecureAccess-Software

other customers mainly have received the correct one, but at least 1 other customer (i guess more) has received the same product as mine.


just for your info, this is a user forum so if you want an official sandisk answer i would suggesto to contact the support directly

Not “official”, but accurate. And it’s not limited to SanDisk.

I doesn’t explaine why 2 customers have received 2 different products :

See my stick (You clearly see it’s not 64GB (not talking about 58.3Go):

And see other customer stick, here you see it’s 64GB (59.6Go);

When it’s advertised 64Gb and you received 62, when it’s advertised 245MB/s and you get 195, when you order the best 64GB key of the world and you don’t receive what you expected, there is something wrong.

Seems that Sandisk is selling 2 different products under the same reference.

Nobody reacted…

If that ~1GB was missing on a 8GB stick, people would be more concerned !

Yah! Me too. Ive been looking for this question.

I got SanDisk Cruzer Dual USB Drive OTG 64GB and it only shows up 58gb and that’s a 6gb, i lost 6gb of what i pay.

@sam24 wrote:

Yah! Me too. Ive been looking for this question.


See the link in my response above for the explanation of why this is.

This is completely normal, but with the way companies advertise, it is a frustrating practice. The missing space is explained by over-provisioning , and the purpose of this is for health & speed benefits.

With flash media (SSDs, SD Cards, USB flash drives, etc.), there is a tiny microprocessor inside the flash drive that controls the NAND flash itself (i.e., the flash media that stores the 0s and 1s using electrical impulses). One task this processor takes on is to ensure data is being saved to “healthy” NAND, and to take “sick” NAND out of use to avoid massive data corruption. In order to accomplish this, the flash drive needs to have spare unused space that it can use to replace any blocks it retires from service. So if a drive “retires” 20 MB of space due to bad blocks, it needs to have a spare 20 MB to replace it with & that 20MB will come from those 2GB that you cannot see. Additionally, some flash drives will use this reserved space as a means to increase file transfer speeds in several different ways. So while your drive is indeed 64 GB, the 2GB are not showing because they have been allocated to the flash drive’s microprocessor. 

Now with that said, the way companies handle this is kinda crappy. If they advertise a product as being a certain size, they should either disclose what the usable size is, or simply make the drive a little larger so that the end user will get 64 GB that they themselves can use (so the size of a 64GB flash drive would actually be 66-68 GB to give the user 64GB to work with. But very few companies do this. If you have an iPhone, take a look at the actual size versus the advertised size. My 64GB iPhone 6s has about 55GB of usable space–a difference explained by over-provisioning.

Hi There,

Thank you for your explanation. It helped me a lot.