How to chose the correct cluster size?

[Jerome]

Hello,
The following table shows the default values that Windows
XP uses for NTFS formatting.
Drive size
(logical volume) Cluster size
Sectors
-------------------------------------------------------
---
512 MB or less 512 bytes 1
513 MB - 1,024 MB (1 GB) 1,024 bytes (1 KB) 2
1,025 MB - 2,048 MB (2 GB) 2,048 bytes (2 KB) 4
2,049 MB and larger 4,096 bytes (4 KB) 8

I'm in the process of reformatting my E partition
(approx. 4 GB) (basically to delete
existing files and create a storage area) and I can chose
an allocation unit size
or chose default which is the largest, see 4KB above.
Which is best; the reason I
ask the question is that in a product information message
they state that small clusters
are better. How does one chose? I plan to use the storage
for My Documents etc. Thanks.

 

[Ken Blake, MVP]

In

I'm in the process of reformatting my E partition
(approx. 4 GB) (basically to delete
existing files and create a storage area) and I can chose
an allocation unit size
or chose default which is the largest, see 4KB above.
Which is best; the reason I
ask the question is that in a product information message
they state that small clusters
are better.

Small clusters are better only in the sense that they waste less
space to slack, the portion of the last cluster of a file which
goes unused because the file size is not an exact multiple of
cluster size.

However, note the following three points:

1. In these days of cheap hard drives, space wasted to slack is
nowhere as significant as it used to be. It may seem like a lot
when measured in MB or even GB, but it's almost always very
little when measured in dollars (substitute your local currency,
if not dollars).

2. 4K, the maximum default NTFS cluster saize, is already a small
cluster. It's the 32K clusters that you can get with large FAT32
partitions that people worry about (at least those who worry
about cluster size).

3. If cluster size gets too small, it can increase I/O time,
since there are more clusters to read and write in each file.

How does one chose? I plan to use the storage
for My Documents etc. Thanks.

Don't worry about it, and just accept the default 4K size.

 

[Jerome]

Thanks for your reply!

-----Original Message-----
In


Small clusters are better only in the sense that they waste less
space to slack, the portion of the last cluster of a file which
goes unused because the file size is not an exact multiple of
cluster size.

However, note the following three points:

1. In these days of cheap hard drives, space wasted to slack is
nowhere as significant as it used to be. It may seem like a lot
when measured in MB or even GB, but it's almost always very
little when measured in dollars (substitute your local currency,
if not dollars).

2. 4K, the maximum default NTFS cluster saize, is already a small
cluster. It's the 32K clusters that you can get with large FAT32
partitions that people worry about (at least those who worry
about cluster size).

3. If cluster size gets too small, it can increase I/O time,
since there are more clusters to read and write in each file.


Don't worry about it, and just accept the default 4K size.

--
Ken Blake - Microsoft MVP Windows: Shell/User
Please reply to the newsgroup


.

 

[Ken Blake, MVP]

In

Thanks for your reply!

You're welcome. Glad to help.

--
Ken Blake - Microsoft MVP Windows: Shell/User
Please reply to the newsgroup