Question for people that understand speed for disk drives

[Larry_OHF]

I have 2 questions:

1. At what speed does a person notice a difference in performance?

I have a 44x CDROM and I want a 52x, because doing the math, it is calculated to be 18% faster. (52/44=1.18181818). Now, a DVD Drive comes with the capability to read a CD at 44x, or 9% faster. (48/44=1.090909). Is there much difference in 9 percent?


2. Is 16x for DVD all we can expect for a while?

Should I hold out for a faster speed? Why does 16x seem so slow to me? Why can it only read 16x, when CD technology is doing 52x ?

[VulcanRider]

Originally posted by Larry_OHF: I have 2 questions: 1. At what speed does a person notice a difference in performance? I have a 44x CDROM and I want a 52x, because doing the math, it is calculated to be 18% faster. (52/44=1.18181818). Now, a DVD Drive comes with the capability to read a CD at 44x, or 9% faster. (48/44=1.090909). Is there much difference in 9 percent?

This is just a guesstimate, but I doubt you'll really notice a difference. Those speeds represent the max performance when the disk is already up to speed, but most (all?) modern CDROMs stop the disk after a few seconds of inactivity to save power. When they have to read again, they have to spin the disk up to speed again before they can read. I'll bet it takes longer to spin the disk up than it does to actually read a file, most of the time anyway.

2. Is 16x for DVD all we can expect for a while? Should I hold out for a faster speed? Why does 16x seem so slow to me? Why can it only read 16x, when CD technology is doing 52x ?

Guessing again, but DVDs have to work a lot harder reading data than regular CDs. DVDs hold more data, so there's a greater volume to transfer -- 4x as much, I think. Plus video is displayed at (I think) 30 frames per second, and each frame could have one of 3 different compression methods used. More action happening in a scene means more of the frame has to be written/read in its entirety, which means less data compression.

What little I learned about it came from www.howstuffworks.com.

[Intrepid]

I have a 48x drive but using "nero CD speed" to measure how fast it actually goes was supprising. It takes about 10 seconds to spin up and starts reading at 24x the only time it actually gets near 48x is when it's right near the outer edge of a 80min CD.
Also 16x in a Dvd reader is plenty, I have a 8x and even that works well.

[andrewas]

Speed rating on a CDROM is bascialy a marketing gimmick. NO CD will ever read at top speed for more than a few seconds. Unless you have a probnlem with your 44, stick with it.

A single speed DVD is much faster than a single speed CDROM, so 16X DVD drives are as fast as 52X CD drives. (OR approximately slow, I dont have the figures to hand)

[InsaneBane]

IIRC the speed for a CDROM tells how much faster (at maximum speed) the drive can deliver data compared to the data flow for a music CD in a CD player. The speed for a DVD on the other hand tells how much faster (at maximum speed) the drive can deliver data compared to the data flow for a video DVD in a video DVD player.

The data flow for a digital video signal is MUCH higher than the data flow for a digital audio signal. That is the reason why 16xDVD is faster than ex. 44xCD.

[img]graemlins/greenbounce.gif[/img]
Insane

[Larry_OHF]

Thanks guys! This sweet info is exactly what I needed.

[Vaskez]

Yeah and final note: the max speed (as touched on above) is only for reading from the outer edge of the disk. Therefore, since CDs are written inwards to out, only CDs that are completely full and only when you are reading that outer edge data will you get the max speed.