- Sep 28, 2001
- 8,464
- 155
- 106
HD wil get slower !?
ok, read on - i'll explain !
Just FYI i am evaluating Diskeeper 10 right now, especially the "i-faast' method and how it lays out the files.
I am otherwise a BIG PerfectDisk supporter - but recently came across some STUNNING no-brainer observations.
By the way i tested and have experience with MOST of the commercial and free defraggers, like oo-defrag, vop-xp, mst-defrag, speedisk, built-in one etc.
(*) HD defraggers, as a result of the file-placement and defragmentation, result in HD free space consolidation.
USUALLY this means that the defragged files on a hardisk get placed "at the beginning" of the HD and the remaining block of free space is "at the end" of the harddisk. Everything looks neat and nice, all files *are* actually defragmented, incl.bootfiles etc.
Only one PROBLEM:
A typical modern Harddisk has it's top sequential speed at the beginning of the HD and is about 50% SLOWER at "the end" (inner side of the physical HD platter). [Reason is that on the outer parts of the platter there are more sectors per rotation, thats simple physics].
In my case (and many different similiar recent HD models) the physical start of the HD gives me 60MB/s while the end gives me 30MB/s. This is normal (See above)....yo ucan also confirm similiar results with tools like HDTach etc.
- So, my HD (which is a 160GB Sata II Hitachi) is 85% FULL and i am even proud that i found 25GB files to delete to keep the free space around 15%, 16%
---> DEFRAGGING with any of the defraggers places my "gap of free space" at the VERY END of the HD, basically making ANY new created file, any newly downloaded file, any write-access SLOW. Since it happens at the bottom of the HD where the speed is 50% slower.
In other words:
IN TIME, while your HD fills up and you defragment/consolidate space your HD (for write access and new files) will be MUCH slower than it was when it was only filled like 10%.
I am evaluating Diskeeper 10 right now (NOT affiliated whatsoever) and i am very pleased to see that my 15% or 16% free space gap ia placed in the FIRST third of the HD - and not (like PerfectDisk etc.) appended after the block of existing files all the way at the end.
There is more to it and i am still checking what it does - eg. very long video files are also placed at the END....so (i am assuming) LESS frequent accessed files.
The result is that for each new file, each download and each write operation i SHOULD get much better transfer rates since the operations happen NOTall the way back in the slow part of the HD.
This observation just made it obvious to me that the plain fact of defragging your HD not *necessarely* always means "performance" but often has two sides - certainly all the older files and my system files etc might be placed nice and defragged - but the free space should NOT over time wander towards the back of the HD otherwise SOME aspects of the system might degrade.
What's needed is a meaningful/intelligent placement of files, like the LEAST accessed files and files where it doesnt really matter (VIDEOS ?) can go there, archives can go there, backups can go there (to the physical end of the HD)..and certainly NOT the free space i am working with. Free space should always be in the first 1/3th of the HD.
So far i actually like what i see with Diskeeper 10 even if there are still some quirks (i am NOT a big fan of scheduling and the bootfile optimization could be better too, IMHO)
my $0.2
ok, read on - i'll explain !
Just FYI i am evaluating Diskeeper 10 right now, especially the "i-faast' method and how it lays out the files.
I am otherwise a BIG PerfectDisk supporter - but recently came across some STUNNING no-brainer observations.
By the way i tested and have experience with MOST of the commercial and free defraggers, like oo-defrag, vop-xp, mst-defrag, speedisk, built-in one etc.
(*) HD defraggers, as a result of the file-placement and defragmentation, result in HD free space consolidation.
USUALLY this means that the defragged files on a hardisk get placed "at the beginning" of the HD and the remaining block of free space is "at the end" of the harddisk. Everything looks neat and nice, all files *are* actually defragmented, incl.bootfiles etc.
Only one PROBLEM:
A typical modern Harddisk has it's top sequential speed at the beginning of the HD and is about 50% SLOWER at "the end" (inner side of the physical HD platter). [Reason is that on the outer parts of the platter there are more sectors per rotation, thats simple physics].
In my case (and many different similiar recent HD models) the physical start of the HD gives me 60MB/s while the end gives me 30MB/s. This is normal (See above)....yo ucan also confirm similiar results with tools like HDTach etc.
- So, my HD (which is a 160GB Sata II Hitachi) is 85% FULL and i am even proud that i found 25GB files to delete to keep the free space around 15%, 16%
---> DEFRAGGING with any of the defraggers places my "gap of free space" at the VERY END of the HD, basically making ANY new created file, any newly downloaded file, any write-access SLOW. Since it happens at the bottom of the HD where the speed is 50% slower.
In other words:
IN TIME, while your HD fills up and you defragment/consolidate space your HD (for write access and new files) will be MUCH slower than it was when it was only filled like 10%.
I am evaluating Diskeeper 10 right now (NOT affiliated whatsoever) and i am very pleased to see that my 15% or 16% free space gap ia placed in the FIRST third of the HD - and not (like PerfectDisk etc.) appended after the block of existing files all the way at the end.
There is more to it and i am still checking what it does - eg. very long video files are also placed at the END....so (i am assuming) LESS frequent accessed files.
The result is that for each new file, each download and each write operation i SHOULD get much better transfer rates since the operations happen NOTall the way back in the slow part of the HD.
This observation just made it obvious to me that the plain fact of defragging your HD not *necessarely* always means "performance" but often has two sides - certainly all the older files and my system files etc might be placed nice and defragged - but the free space should NOT over time wander towards the back of the HD otherwise SOME aspects of the system might degrade.
What's needed is a meaningful/intelligent placement of files, like the LEAST accessed files and files where it doesnt really matter (VIDEOS ?) can go there, archives can go there, backups can go there (to the physical end of the HD)..and certainly NOT the free space i am working with. Free space should always be in the first 1/3th of the HD.
So far i actually like what i see with Diskeeper 10 even if there are still some quirks (i am NOT a big fan of scheduling and the bootfile optimization could be better too, IMHO)
my $0.2