Transfer Rate/ Seek Time Question

[fastman]

Looking at getting a used SCSI CD-Rom for $35.00 One has a Seek time of 95ms and a Transfer Rate of 20MB/Sec and the other has a Seek Time of 85ms and a Transfer Rate of 10MB/Sec. I believe the Seek Time difference is not that much of a deal. But is the Transfer Rate would I see a difference, TIA.

 

[Shmorq]

I think the 20MB/s and the 10MB/s are just the speed of the interfaces (SCSI-2 and SCSI respectively... is that correct?). Unless your CD-ROM is a 60+ X CD-ROM, I don't think you'll be approaching the 10MB/s limit.

 

[bozo1]

I hope you mean 9.5ms and 8.5ms. The one with the higher transfer rate will give you the best performance but you will still be well below the speed of a current ATA100 drive.

Edit: oops, my bad. I thought you were talking hard drive.

 

[cvlegion]

Depends on how many accesses you have. If you are transferring randomly, you will benefit by having a lower seek time. If you are tranferring sequentially, you will benefit by the higher transfer rate.

However, are you really sure those are the actual transfer rates. I highly doubt it. If these are CD-ROM's and not DVDs, you will not get that fast of a transfer rate. Those sound more like bursts. The seek times are about right. If it were me, I would get the one with the lower seek time.

 

[thorin]

Yes those are the interface speeds.

It would take roughly a 66x CDROM to make 10MB/sec.

1x CDROM = 150KB/Sec
66 x 150KB/Sec = 9.9MB/Sec

Thorin

 

[Shmorq]

While you're at it, can you or anyone else tell me the speed of a 1X DVD-ROM drive?

 

[fastman]

I think Thorin said it:

<< 1x = 150KB/Sec >>

. Thanks all.

Edit: ahh DVD, never mind.

 

[thorin]

&quot;While you're at it, can you or anyone else tell me the speed of a 1X DVD-ROM drive? &quot;

1x DVD = 1.385MB/Sec

Thorin