FAT32 and clusters

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Mrodfr
Posts: 29
Joined: Wed Jul 06, 2011 5:29 pm

FAT32 and clusters

Post by Mrodfr »

Hello,

I have optimized my 16go USB stick by changing the clusters. Because the speed copy on PC change from 15 mb/s to 30 mb/s.


from the documentation:

This mountlist FSSM environment value can is really treated
as "FAT physical blocks" per "FAT sector" and be set to
a power of 2 to enforce a specific FAT sector size of 512,
1024, 2048, 4096 bytes, when multiplied with the physical
sector size of the underlying disk.

I'm using a 512 block on the key but a bigger cluster size.

The result is a requester who said:

volume has broken clusters geometry. can't mount it ?



- Please, first, add more clusters support for the next update.

- Remember me the clusters supported on AOS4 actually, thanks.

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ZeroG
Posts: 119
Joined: Sat Jun 18, 2011 11:31 am
Location: Germany

Re: FAT32 and clusters

Post by ZeroG »

You tried to mount a USB stick using a different cluster size, but don't re-formated it using that changed mountlist?

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Mrodfr
Posts: 29
Joined: Wed Jul 06, 2011 5:29 pm

Re: FAT32 and clusters

Post by Mrodfr »

Hello,


NO. I have formatted, using a PC tool (I think FAT32formatter),my 16go USB key. I could said more tomorow at job office. the tool is installed on the job office PC ;-)

the tool test the good cluster for the size of the FAT32 medias. I have increased the copy speed from 15mb to 25mb with this tool and I have finally formatted my USB key with this tool with the recommended high clusters.

Unfortunately, the key isn't recognized more on the amiga.

I have made that recently that mean I'm not sure the key work with update2.


More support of the size of clusters (FAT) will increase the speed copy.

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tonyw
AmigaOS Core Developer
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Re: FAT32 and clusters

Post by tonyw »

I think you can assume that CrossDOS only supports the standard cluster size. It is unlikely to be expanded.
cheers
tony

xenic
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Joined: Sun Jun 19, 2011 12:06 am

Re: FAT32 and clusters

Post by xenic »

tonyw wrote:I think you can assume that CrossDOS only supports the standard cluster size. It is unlikely to be expanded.
I doubt if cluster size is the problem anyway. I ran some quick copy tests with 8 files totaling 116 MB. Here are my results with Update3 installed:

Copy from Ram: to USB mem stick formatted with FAT= 280 seconds
Copy from USB mem stick formatted with FAT to Ram:= 13 seconds
Copy from Ram: to USB mem stick formatted with SFS= 25 seconds
Copy from USB mem stick formatted with SFS to Ram:= 12 seconds

As you can see the FAT write speeds are unbelievably slow. My test with an SFS formatted mem stick indicates that the problem isn't with USB; the speed is far greater than I got with USB 1.1. Something appears to be wrong with CrossDosFilesystem because the write speed are comparable to USB 1.1 instead of USB 2.
AmigaOne X1000 with 2GB memory - OS4.1 FE

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Hypex
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Re: FAT32 and clusters

Post by Hypex »

Is CrossDOS using any cache buffers? Can these be specified?

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Mrodfr
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Joined: Wed Jul 06, 2011 5:29 pm

Re: FAT32 and clusters

Post by Mrodfr »

The support of the clusters should be expanded.

I could double the speed read and write on my 16go USB stick (FAT32 formatted).

Thanks to previous poster about speed test with FAT and SFS. I know It's a FAT32/CrossDOSfilesystem only now).

FAT32 support should be expanded to share datas easily with others platforms !!!!!

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