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Usb allocation size

lorcav123

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So this is situation:
- I know that default windows allocation size is 4096 bytes but I am thinking to format my sd card 32gb to 64 kilobytes. On sd card will be only movies and TV shows(file size from 350mb to 4gb). On USB stick 64gb (movies, pictures, documents) I was thinking to set it to 32 kilobytes. Is that good? They will sll be in exFat format.
Apparently bigger alloaction size should speed things.

- Is it best to use quick format or normal format on new cards?

Noob question, I will try to test speed with couple of different formats, when someone recommends me 16K size that means 16384 kilobytes and 4K is 4096 kilobytes? Or 16K is 16384 bytes?
 
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JD

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64K allocation size means that every file, even if it's smaller than that, will use 64KB. Generally wastes a lot of space if you have a lot of small files.

I'm not sure how much difference you'll notice on flash-based media. It might help a hard drive where blocks become fragmented and causes longer seek times, but that doesn't apply on flash/SSD.

I'd suggest doing a normal/full format on any new storage device just so you know it's all zero'd out. Also generally will alert you to any drive issues before you start using it.
 

lorcav123

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I read that changing allocation size will speed up things. On sd card they will be only movies so my guess is that bigger the allocation size, faster the sd card. Similar for usb stick but since it will have multiple formats (documents, pictures, movies) allocation size will be 32K. So speed up is my goal.

I found post from my yesterday search from one guy that has seen improvements:

https://www.reddit.com/r/AskComputerSci ... _size_for/

Also yesterday I tryed Crystal disk mark test with couple of different allocation sizes. I set set size to 2GB (maybe to eliminate cache memory??).

Tested with allocation size 32k (full format):



Then I quick formated usb stick and selected default option and after formating it was set to 128K (how is that default?):



and for the last test I used smallest size 4096 bytes (quick format):




- Why is speed to small on 128K test? Should I set test on more passes (I sset to only one pass)? Now I am worried that something is not wrong with USB...
- Is there a program that can verify me the USB stick health?
- Can you give me instructions in what program (is Crystal mark the best?) to test and how?

Stick is Adata S102 pro 64GB, it should be above average as far as I read.
 

Izerous

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Your playing with micro optimizations in a situation where at the user level you would never even notice the difference between settings. You might swing copy times a few seconds, and it isn't going to effect playback.

Advertised and real world numbers for data transfer rates also almost never line up especially on SD/USB drives.
 

lorcav123

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Yeah but on that link I posted above from reddit seems like a good difference. Why did I get a awful write score at 128K? Is it only becasue one pass? How can I check is my USB stick working correctly?
 

JD

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I don't think I've ever seen anyone suggest a 128K allocation size, so I wouldn't worry too much there. It's possible that the flash controller simply doesn't understand what to do with that size. Odd why Windows would pick that as the default though.

I would stay under 64K, though by your tests, it looks like 4K was the fastest anyways which is generally the default.
 

lorcav123

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For final test (1gb test file size) I decided to set it on 16K allocation. I expected higher 4KiB values in Crystal mark, some other cheaper stick have there around 2-3mb speed.




Why on ATTO is so many speed oscilation? Mostly benchmark I see in ATTO have normal stable scale.

And why on 50mb test I get slower speed:



For example this amazon review (50mb crystal mark test) seems to have much higher speed than mine:

https://www.amazon.com/gp/customer-revi ... B00BF9HYZ4

Maybe different program version?
 
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Sagath

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You'd have to compare apples to apples with them. You're probably on a different motherboard than them, with a different USB chipset, or drivers.

There are a million factors at play, and you're worrying about a <5% variance in your values, which is well within what testers would call 'margin of error'.
 

lorcav123

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OK, so conclude this thread you think that my usb stick is working ok? I am most worried by those ATTO benchamark picture because every benchamark from that program I saw for other USB sticks looks like a normal scale, from lowest to higher values, slows increasing in test.
 
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Entz

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Looks fine, unless your planning on doing continuous writes to it constantly its one and done anyways.

There are far to many variables, maybe your stick is a slightly different revision with different cache/firmware/nand or your USB chipset is different or maybe windows changed their drive system for removable devices since that was tested or they ran it in suicide mode etc.

The only thing I would ever do is run "H2testw" to make sure its actually as big as it says it is and not fake.
 

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