I Just wonder - What 'Allocation Unit Size' should be used?

Okay - some more information. I did a search and found many therads about this but they are really old.

I'm going to format my drive as NTFS, ExFat is also an option, but as it looks like now NTFS is the best to go.

I generally have large files and some small-sized files. By large files I mean any file up to (generally) 10-15GB. I can say it like this;

30% of my files 4GB + (anywhere up to 30GB single file, those are rare tou)
10% of my files somewhere between 1GB and 4GB.
50% of my files are somewhere between 500 mb and 1GB.
5% of my files are documents, somewhere between 1 and 2 MB.
5% of my files are pictures.

Asking for my 'My passport' drive, 1TB. USB 3.0ish but I only use it with 2.0

What do you think would suit it best?
Min is 4096 byte and max is 64 kilobyte.

I have about 100GBs free. However, I don't care if 64kb uses more space then 4096b.

And I'm ofcourse not stupid enough to do a fast format..

 

1) do a fast format (nothing stupid about that except if you think the disk is damaged)
2) chose the default. it doesn't really matter.

 

Actually, I think something is wrong. I don't know if you saw my other therad a while ago but when I first moved from My book drive to my passport drive many of my files got damaged and is unusable... So, now I'm going to empty my drive format it, and move files I know are not damaged back to my drive and see if I get any reading errors. If I do so, my drive may be faulty.

I did actually read from the old therads that higher size is, files will open faster.. What do you think?

 

well, first of all, check if your drive is buggy. that's priority one.

other than that, well.. shouldn't really matter much what size it is. at least not for big files. but you could test trough measuring. i think it's just not worth the effort.


oh, i just had do check: you use it with usb2? then it should never matter. the drive is about 5x as fast as what usb2 delivers, so it does not matter at all how fast the drive is.

 

Okay - thank you. I have it at 4096 now. Rep added. I'll try 64k and see if any file gets damaged... It is actually very fast with transfers etc. Moves a 4GB movie inn less then 10 seconds with my laptop on my signature. The transfer rate, accordin to Windows is about 140-150ish.. Sometimes up on 200MB/s.. That is crazy.

 

can't be usb2, then. that would be more like 20-30MB/s max.

 

My laptop does not have USB 3.0. It is a 2-3 years old HP. But, it does have a fast SSD But again, it is limited what that cable can transfer, but seriously..

 

those numbers are impossible on usb2. they, actually are impossible for the ssd (when you write to the ssd).

so something's wrong? you sure it's usb? maybe you're using an esata plug?

 

You're probably talking 200 Mbps which is equal to 25 MBps.

 

Truth. With overhead it is like 20~ MBps.

 

I'll post up a screenshot when I'm back home.. And yes, it is not esata or something like that, it is pure USB 2.0 baby

 

If you read the specs of USB 2.0, it's max throughput is 480Mbps or 60MBps (1 byte (B) = 8 bits (b)). With overhead and maxing out the connection with a much faster drive, you won't be able to get above 40-50MBps in real life (most often you'll only see 30-40MBps). So it's impossible for you to transfer files at 200MBps over USB 2.0...

 

I know you have hard time understanding this, so do I. I'll post a image soon as I can

 

The issue is understood. It's a matter of citing the right units when talking about transfer rates. 1MB/s != 1Mb/s != 1MiB/s != 1Mib/s

!= means "does not equal" in math parlance.

Most of the time, when numbers don't add up (e.g., 300GB hard drive reported as 279GB), it's because manufacturers (probably their marketing people) and OS makers can't agree on a single standard.

• Interesting and confusing aside: the 3.5" 1.44MB floppy disk only holds 1.4MiB or 1.47MB. The 144 came from 1,440 KiB x 1000, nicely mixing two standards.

 

Actually the whole MB and MiB can get confusing. HDD manufacturers market the drive size with 1GB = 1000MB instead of 1GB = 1024MB. Windows reports the HDD size with 1GB = 1024MB so that's why a HDD marketed as 500GB will show as 465GB in Windows. I've got no idea how it reports the transfer speed but i suppose it still works in base 2 so 1MB = 1024 kiloBytes and so on. We're seeing MiB in use now though so that might change.

@tunay 1bit is a binary digit so either a 0 or a 1 and a Byte is 8bit. When you see Mb/s it's Megabit per second and when you see MB/s it's MegaByte per second so the value is 8 times lower. Things get confusing thanks to marketing schemes.

The mebibyte (MiB) was adopted in order to clear things up so people could use MegaByte as 1000 kiloByte and MebiByte as 1024 KibiBytes.

Traditional usage of the greek prefixes:
kilo = 1000 (10^3)
Mega = 1 000 000 (10^6)
Giga = 1 000 000 000 (10^9)

However since computers work in binary, people started using those prefixes for binary data as
kilo = 1024 (2^10)
Mega = 1024x1024 (2^20)
Giga = 1024^3 (2^30)
Which started some confusion, then HDD manufacturers used the traditional use of those prefixes to increase marketed HDD size.

That's why the kibi, Mebi, Gibi etc. prefixes were created
kibi = 1024 (2^10)
Mebi = 2 ^20
Gibi = 2^30
At this point it's still a confusing mess of prefixes used to determine HDD size and transfer speeds since some use the new prefixes, other don't. Those who don't use the new prefixes either use the greek prefixes kilo, mega, giga etc in the traditional sense or as people in computing used them like how windows determines file sizes.

I feel like my post is confusing but i haven't found a better way to explain it yet...

 

capitalization of b vs B trumps everything else. Anything else usually falls within an irrelevant margin of error for most people.

 

True enough