How fast is PFS-2 ?

GREED claim that PFS-2 is between 2.5 and 5 times faster than FFS.

There is no doubt that PFS-2 is faster than FFS.  If you do not believe me try it.  There is a demo if you want to try before you buy.

Performance fluctuates because it depends on so many factors :-

• Speed of interface (Zorro II/Zorro III)
• Processor and speed
• Use of controller (SCSI/IDE)
• Partition size
• Speed of harddisk (sweep time, access time, cache, track size, rpm)
• Processor and clock
• Amount of RAM available
• Partition age and fragmentation
• Size of cache
• On PFS-2: used filenames
• Access history (Cache !)
• Directory sizes, access sizes, software/user behaviour

GRRED have published the results of a comparison tests between PFS2, FFS and SFS. They conclude that PFS2 is the fastest and most stable filesystem for the Amiga. Large directories FFS and SFS become slower and slower and unreliable. The larger the directory the bigger the distance between PFS2 and FFS and SFS gets.

The test was performed on an A4000/040 with an IDE Quantum Maverick 540 disk. They claim that the difference will be even greater with SCSI. These results are averages of the same test performed a couple of times. It is a practal test performed in DOS, these are real, not fictional results. Everything is in seconds. Make sure to use exact the same conditions (partition,buffers, etc) for every filesystem you test. Take at least 1500 files and 15 MB so the results will be clear.

TOTAL: 2633 files - 65 directories - 39900 blocks

date
copy dh0:main/#? to dh0:test/ all quiet
date
delete dh0:test/#? all quiet
date

A similar test was performed in the Christmas issue of Amiga Format and the results were the same. Apparently SFS couldn't even finish all the tests because of it's many problems.

Note that disk speed is NOT a good test of a filesystem's preformance.  It is designed to test a disk's performance. Have a look at it's results :-

DOS5

Creates  1000 files of     128 bytes :     4 files/second
Scan all files in a directory        :  2844 files/second
Lock and unlock a random file        :    11 files/second
Open and close a random file         :    11 files/second
Load a random file                   :    11 files/second
Deletes  1000 files                  :   199 files/second
Random seek/reads of  2048 bytes in
                   2097152 byte file :    44 times/second
Read data using   65536 byte buffer  :  1063 kB/second
Write data using   65536 byte buffer :   867 kB/second


SFS (including setcache!)

Creates  1000 files of     128 bytes :    19 files/second
Scan all files in a directory        :  2527 files/second
Lock and unlock a random file        :   289 files/second
Open and close a random file         :   252 files/second
Load a random file                   :    33 files/second
Deletes  1000 files                  :   112 files/second
Random seek/reads of  2048 bytes in
                   2097152 byte file :    44 times/second
Read data using   65536 byte buffer  :  1519 kB/second
Write data using   65536 byte buffer :  1825 kB/second


PFS2

Creates  1000 files of     128 bytes :    30 files/second
Scan all files in a directory        :  2990 files/second
Lock and unlock a random file        :   176 files/second
Open and close a random file         :   161 files/second
Load a random file                   :    49 files/second
Deletes  1000 files                  :   134 files/second
Random seek/reads of  2048 bytes in
                   2097152 byte file :    54 times/second
Read data using   65536 byte buffer  :  1429 kB/second
Write data using   65536 byte buffer :  1384 kB/second

As you can see according to diskspeed SFS is slower than DOS5 on some points and DOS5 is faster than PFS2 on some points. Any PFS2 user will see that this has nothing to do with the real performance of PFS2. Just compare it to 'real use' results above ! (or the Amiga Format's comparison if you think GREED cheated on the figures)