Cluster Help

[nymph4]

Am I right in that FAT 16 can only support up to a 2. GB Hard Drive?
And FAT 32 Can support up to a 2 TB Hard Drive?

I get two diferant thoughts on this on the net.

[reddevilggg]

The Max. volume size for FAT16 is 2GB

The Max. volume size for FAT32 is 32GB

The Max. volume size for NTFS is 2TB

This is how I understand it , but i'm still studying for my A+, I just hope a guru confirms this.

[nymph4]

Ok here it goes??

Every time I look on the NET for information about FAT 16 FAT 32 I get two diferant things?

I never get the right information does anyone know of a gook web site that will tell me things like?
How many Cluster are it FAT 16  32
What the MAX Cluster Size is for FAT 16  32
What OS  support what FAT
And all good ods and ends like that??

[Dusty]

Google again comes up trumps.    Following is an extract from this page which is part of this site.

# FAT12: The oldest type of FAT uses a 12-bit binary number to hold the cluster number. A volume formatted using FAT12 can hold a maximum of 4,086 clusters, which is 2^12 minus a few values (to allow for reserved values to be used in the FAT). FAT12 is therefore most suitable for smaller volumes, and is used on floppy disks and hard disk partitions smaller than about 16 MB.

# FAT16: The FAT used for most hard disk partitions uses a 16-bit binary number to hold cluster numbers. When you see someone refer to a "FAT" volume generically, they are usually referring to FAT16, because it is the de facto standard for hard disks. A volume using FAT16 can hold a maximum of 65,526 clusters, which is 2^16 less a few values (again for reserved values in the FAT). FAT16 is used for hard disk volumes ranging in size from 16 MB to 2,048 MB.

# FAT32: The newest FAT type, FAT32 is supported by Windows 95's OEM SR2 release, as well as Windows 98. FAT32 uses a 28-bit binary cluster number--not 32, because 4 of the 32 bits are "reserved". 28 bits is still enough to permit ridiculously huge volumes--FAT32 can theoretically handle volumes with over 268 million clusters, and will support (theoretically) drives up to 2 TB in size. However to do this the size of the FAT grows very large.

Then there's this one with a table showing OS/FAT compatibility.

[nymph4]

OK I think I know ware I am geting lost on FAT 16 and FAT 32?

If you use FAT 16 on a Big or Small Hard Drive it must cover the whole Hard Drive with Cluters RIGHT???

So if you have a small Hard Drive it will not be able to put 65,526 Cluters because it will not be able to fit them all on the Hard Drive RIGHT???

So it will put down a diferant number of Clusters but it still must cover the whole Hard Drive RIGHT???

[Dusty]

So if you have a small Hard Drive it will not be able to put 65,526 Cluters because it will not be able to fit them all on the Hard Drive RIGHT???

No, the cluster number remains the same but the cluster size diminishes.  See the table here and note how the cluster size increases as the disk size also increases.

If you use FAT 16 on a Big or Small Hard Drive it must cover the whole Hard Drive with Cluters RIGHT???

You haven't defined what you consider to be Big or Small.  Fat16 is not supported (cannot be used) on disks (partitions) larger than 2gb (see here) and see my reply to your post here.

[nymph4]

What I ment is this.

If you use FAT 16 on a Hard Drive that is 2,048 M.B.
It will put 65,526 Clusters down and every Cluster will be 32 kB

Now what I don't get is if the Hard Drive is 720 M.B. it will put down less Clusters.
And the Cluster size will not be 32 kB

Now I do get that the max number of Cluster is 65,526 not that it will put that many on every Hard Drive.

This it what I ment??

[patio]

The cluster size will always be 32kb......
Do the math to find out how many clusters will be created on any size drive...

[Dusty]

FAT16.
For a logical drive of 720mb the cluster size will be 16k not 32k

The table below is extracted from kb67321

                  Drive Size         FAT Type     Sectors     Cluster
               (logical volume)                   Per Cluster     Size
               ----------------        --------    -----------      -------
                 0 MB - 15 MB           12-bit          8            4K
                16 MB - 127 MB        16-bit          4           2K
               128 MB - 255 MB       16-bit          8           4K
               256 MB - 511 MB       16-bit         16          8K
               512 MB - 1023 MB     16-bit         32          16K
              1024 MB - 2047 MB     16-bit        64          32K

No, the cluster number remains the same but the cluster size diminishes.

OOPSIE, I boobed on that statement, the cluster number obviously must also diminish.  Doing the math shows that on a 720mb logical drive with a cluster size of 16k there will be  approx 45,000 clusters.

Sorry about the error.

                 

[nymph4]

Ok I have the chart you sent me on FAT 16.

So if you have a Hard Drive 512 M.B. in size the Clusters will be 16 kB in size and it will need 32 Sectors to make every Cluster.

And if you have a Hard Drive 1024 M.B. in size the Cluters will be 32 kB in size and it will need 64 Sectors to make every Cluster.

So I see that the Cluster size changes because every Setor is 412 Bytes in size and it may take more or less of them to make every Cluster RIGHT???

[Dusty]

So I see that the Cluster size changes because every Setor is 412 Bytes in size and it may take more or less of them to make every Cluster RIGHT?Huh??

I don't know where you get the idea that every sector is 412 bytes in size but I'll assume that it's a typo for 512 bytes - so YES!!!   Every sector is 512 bytes in size and the number of sectors per cluster and the number of clusters per logical drive can vary with the logical drive size.   The maximum number of clusters per logical drive using the FAT16 system is 65,526.

[nymph4]

Ok I got the chart for FAT 16 and all the diferant size Hard Drives it supports and Sector per Cluster and Size of Cluster.

Do you have a chart for FAT 32 like that??

[nymph4]

OK I have it and I think I have put everything down for FAT 12 FAT 16 FAT 32.
Please go through my list to see if I have it correct?
And you will see some things BLANK because I did not know and can not finde what to put. If anyone know please fill in my chart and past it in the reply thanks.

F.A.T Type = 12
Maximum Partition size = 16 M.B.
Maximum number of Clusters = 4,086
Cluster Size = 4. k.B.
Sectors Per Cluster = 8.

F.A.T Type = 16
Maximum Partition size = 16 M.B. / 127 M.B.
Maximum number of Clusters = 65,526
Cluster Size = 2 k.B.
Sectors Per Cluster = 4.

F.A.T Type = 16
Maximum Partition size = 128 M.B. / 255 M.B.
Maximum number of Clusters =
Cluster Size = 4. k.B. 
Sectors Per Cluster = 8.

F.A.T Type = 16
Maximum Partition size = 256 M.B. / 511 M.B.
Maximum number of Clusters =
Cluster Size = 8. k.B.
Sectors Per Cluster = 16 . k.B.

F.A.T Type = 16
Maximum Partition size = 512 M.B. / 1023 M.B.
Maximum number of Clusters =
Cluster Size = 16 k>B.
Sectors Per Cluster = 32

F.A.T Type = 16
Maximum Partition size = 1024 M.B. / 1047 M.B.
Maximum number of Clusters =
Cluster Size = 32 k.B.
Sectors Per Cluster = 64

F.A.T Type = 32
Maximum Partition size = 32.52 M.B. / 260 M.B.
Maximum number of Clusters
Cluster Size = 0.5 k.B.
Sectors Per Cluster = 1.

F.A.T Type = 32
Maximum Partition size = 260 M.B. / 8. G.B.
Maximum number of Clusters
Cluster Size = 4. k.B.
Sectors Per Cluster = 8.

F.A.T Type = 32
Maximum Partition size = 8. G.B. / 16 G.B.
Maximum number of Clusters
Cluster Size = 8. k.B.
Sectors Per Cluster = 16

F.A.T Type = 32
Maximum Partition size = 16 G.B. / 32 G.B.
Maximum number of Clusters
Cluster Size = 16 k.B.
Sectors Per Cluster = 32

F.A.T Type = 32
Maximum Partition size = 32 G.B. / 2. T.B.
Maximum number of Clusters
Cluster Size = 32 k.B.
Sectors Per Cluster = 64

[nymph4]

I am sorry for asking but do I have it yet?

I do not know if I had a Reply my Computer was acting up with the posts THANKS

[Dusty]

Do you have what

You have a table showing Logical Volume Size and Cluster size, just divide the Logical Volume size by the Cluster Size and you have the approximate number of clusters on that volume.  You didn't really expect one of us to do that for you