Question about large hard drive performance under Win2K.

[Ken Varn]

I have a system that I am doing development under Windows 2000 that stores a
large quantify of small image files at a high rate (1 file every 20
milliseconds). Each file has an average size of 12 - 14K. I am storing to
an ATA-100 Maxtor 250 gig. hard drive. The performance of the drive seems
to keep up for the first 220+ gig. of storage, but when I cross the 220 gig.
threshold, performance starts getting worse and worse. By the time the hard
drive has about 2 - 4 gig. left on it, the performance has reduced by about
half.

I am not sure if this is related to the Windows 2000 NTFS file system or the
hard drive itself, so I tried the same test with a 180 gig. Hitachi hard
drive. The same results occurred when the drive was nearing capacity.
Performance degraded significantly.

So now I am concerned that there may be issues with NTFS and the quantity
and size of the files in relation to performance. Could someone explain why
this is happening and whether this is a bug or implementation problem? I
really need the performance to stay consistent from when the drive is empty
to when it becomes full.

--
-----------------------------------
Ken Varn
Senior Software Engineer
Diebold Inc.
(e-mail address removed)
-----------------------------------

 

[Bob I]

Performance on a nearly full harddrive ALWAYS goes to heck. HPFS
minimized the requirement to do full sweeps of the platters but still
suffered to some extent. When you get to 80% buy more drives is about
the only answer.

 

[Ken Varn]

So are you saying that I should allow at least 20% of the drive to be free
in order to have the most optimal performance?

--
-----------------------------------
Ken Varn
Senior Software Engineer
Diebold Inc.
(e-mail address removed)
-----------------------------------

 

[Andy]

The closer you get to the center of the disk, the slower the data
transfer:
Hard disk drive specifications
Deskstar 180 GXP
4.4.4 Data transfer speed
Data transfer speed 180 GB model (Mbyte/s)
Disk-Buffer transfer (Zone 0)
Instantaneous - typical 66
Sustained - read typical 56.3
Disk-Buffer transfer (Zone 26)
Instantaneous - typical 34.5
Sustained - read typical 29.4
Buffer-Host (max) 100

 

[Bob I]

If you want fastest stay under 85-90%. If you hit 80% plan to add more
drive. It's a mechanical system and the further you move the arms to
locate and retrieve data the longer it takes. Most of the drive mfg.
provide the data you would be interested in looking at as far as full
platter seeks and data x-fer rates from various locations.