Why are these USB drives a different capacity?

[Cyber Akuma]

Ok, so these two drives you see in my screenshot from my PC are the same physical drives shown right below them. They also both have an exact clone of each other's data. They are also both 32GB models and from the same manufacturer, though clearly different models.

 

 

Yet, both have a different capacity and amount of space left.

 

Now, if it was just the free space left and the capacity was the same, I would assume they were just formatted with different file cluster sizes. But even the total capacity is different, one has nearly a gig more than the other! What would cause this?

[Lant]

Have you checked disk manager to see if there is any unpartitioned space on the right hand one?

[Odom Member]

How are they formatted? Both NTFS? exFat?...

[Anibal P]

What are they formatted in?| Possibly the difference is there 

[Xahid]

Have you checked disk manager to see if there is any unpartitioned space on the right hand one?

+1

That's the only thing, you need to check.

[Cyber Akuma]

Have you checked disk manager to see if there is any unpartitioned space on the right hand one?

 

 Yeah, I forgot to mention. I checled the Logical Disk Manager and didn't see any unpartitioned space.

[vcfan]

when there are bad sectors, the flash controller will mark these sectors as unusable, so capacity and amount of free space will be decreased. these could very well be the same exact chips, but one has bad sectors.

[+Random Stranger Subscriber¹]

when there are bad sectors, the flash controller will mark these sectors as unusable, so capacity and amount of free space will be decreased. these could very well be the same exact chips, but one has bad sectors.

 

yeah, that what happened to my drive.  capacity went down, otherwise everything normal.

you did not check them against each other when they were new?   

 

or different formatting as people above already mentioned. 29.8 and 29 both would be rounded up to 32GB on the box.

 

also when a manufacturer says 32GB   it is not an exact number.  so could just be different.

[Torolol]

use chkdsk in read-only mode to check it out.

[T3X4S]

stop buying junk drives 

 

[netty2014]

ask the manufacturer its probably the architecture of the chip

[xendrome]

screenshot of disk management please, and screenshot of chkdsk details. Likely an issue with sector size/format type

[BinaryData]

Honestly, I don't think its possible to get exactly 32GB. I have 50ish 2GB - 32GB drives, not one of them has the full listed amount. Maybe BudMan can give you a specific reason as to why, but even my HDD or my SSD are 5 - 10GB off the stated amount.

Hell, my 1TB drive, NTFS or Linux format, is still missing 31GB of space. Not sure how or why, but it's whatever. I have 2 drives in sequential sequence, both are ~30GB from their true listed amount.

[+Nik Louch Subscriber²]

Maybe BudMan can give you a specific reason as to why

 

I know you worship him but seriously?

[Lant]

29.8GB is the correct size (32,000,000,000 / (1024^3) roughly equals 29.8)
 

Will be interesting to see the chkdsk output.

[firey]

Honestly, I don't think its possible to get exactly 32GB. I have 50ish 2GB - 32GB drives, not one of them has the full listed amount. Maybe BudMan can give you a specific reason as to why, but even my HDD or my SSD are 5 - 10GB off the stated amount.

Hell, my 1TB drive, NTFS or Linux format, is still missing 31GB of space. Not sure how or why, but it's whatever. I have 2 drives in sequential sequence, both are ~30GB from their true listed amount.

 

 

It's because human math and computer math are not equal.

[+Neyht Subscriber²]

My guess is that one company measured the drive space before format and the other company measured after format.  Both companies used the base 10 measurement.

[+Random Stranger Subscriber¹]

My guess is that one company measured the drive space before format and the other company measured after format.  Both companies used the base 10 measurement.

 

he did say it is from the same manufacturer, you know.    

 

 

still, could be an issue for different models.

[Pam14160]

Betting you wish you haven't ask that question here on Neowin. . . .

[nekrosoft13]

when there are bad sectors, the flash controller will mark these sectors as unusable, so capacity and amount of free space will be decreased. these could very well be the same exact chips, but one has bad sectors.

yap, and both drives probably have memory chips from different manufactures, capacity can be slightly off.

[Cyber Akuma]

when there are bad sectors, the flash controller will mark these sectors as unusable, so capacity and amount of free space will be decreased. these could very well be the same exact chips, but one has bad sectors.

The smaller one the right is brand new, I had just gotten it the very day I posted this and the first and only time I ever even plugged it in was what you see here to clone the old drive to the new one, so nearly a gig of bad sectors on a brand new flashdrive is pretty unlikely.

[sc302 Veteran]

With the amount of information provided I can properly deduce that the answer to your question is 42.

 

This answer may change once more information is provided, but for now that is the best answer that can be given.  That also answers why grass has to be green but flowers can be multicolored and why tree bark is brown not purple.

 

There is no relevance that just because you have taken it out of the box to it being perfect...there have been drives that have contained bad sectors or that have been doa right out of the box.  It could be a manufacturing defect, it could be different file formats, it could be a number of different things.  It could be because the sun is yellow and you are a salmon colored (which has about as much relevance as you taking it out of the box and plugging it in and assuming everything is good). 

 

A novel idea would be to call the manufacturer and ask them what the issue is, they can correctly inform you as to what is going on...there could be a hidden partition on it (you have not sent us anything that would suggest not, nor have you done anything to help us with more information other than ask the question why.  So please see the first sentence in this post...questions with lack of information lead to speculation.   You will never get an educated, informed, or the correct answer).

[sc302 Veteran]

My money is on allocation unit size.

Which should be 29.8GB...it is a little short of that.

 

Even my 32's are 29.2GB for what it is worth.

[xendrome]

I guess OP doesn't want to post Disk Management or CHKDSK results for us to determine the exact cause.

[Cyber Akuma]

My money is on allocation unit size.

Woulden't that affect only the free space/space the files take up though, not the actual capacity?

I guess OP doesn't want to post Disk Management or CHKDSK results for us to determine the exact cause.

I'm not home right now, I'll do it when im home.