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mjmcinerney

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cd-rw drive

Hi. asked a question earlier which was answered and graded. I want to ask another question along the same lines. My earlier question was about occassional hesitations when viewing mpegs with my hp cd r-w drive. Evidently this is not uncommon in cdrom drives. However when I tested the same rom in my reg. cdrom drive, it seemed to do it less frequently than my new hp rewritetable drive. Is it more common in Cd-rw drives than non rewriteable drives? Is my new hp drive okay? It records and copies great. P.S Both drives are connected to their own ide controller.  
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mjmcinerney

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Edited text of question.
Edited text of question.
What is the speed of your regular CD-Rom as compared to the CD-RW? Maybe the speed difference has alot to do with it
Another thing too, Do you have DMA enabled for either one of them?
Both are 24x. no dma enabled. Does the fact the rewritable has to multiread have any bearing?
Both internal ide drives ? Most likely the answer is the buffer size-difference between the two
Well part of the reason maybe the CD-RW checks the media to see what it is before it reads the actual data file, where as since the CD-Rom will only read it does not do that.

This is for the first time you access the CD-RW, what about if you click on another file, does it get faster then or still take longer?
Its not so much a speed issue. Files come up quickly enough. Its just that the cd-rw is not always has "smooth".
This problem is intermitant and only lasts a second{hesitation].
BOLIX, can you explain your answer about the buffer size difference of the ide drives. i can live with this. its not a big deal, if its normal. I just want to be sure my new drive is not defective.
Thanks
My CDR/W, even though it is rated at 24x, is no where near as fast as my 12x is.  Infact, when I copy from CD-R to HDD, I always use the 12x drive.

Why this is the case, I have no idea.  BOLIX metions buffer sizes, but I honestly believe that in the case of CDR/W drives, the buffer is more used when burning more so than reading.  My CDR/W has a 2Mb buffer which is 10x larger than the buffer in my old 12x, yet it is slower.

The only thing I can put it down to is maybe the seek times are slower on a CDR/W than a normal CD-ROM.  My CDR/W spends quite a lot of time seeking when I am copying multiple files from it, but my regular CD-ROM will copy the same CD without seeking at all (apart from the initial seek).

One thing you could try is to open the System Properties (Control Panel), select the Performace Tab, click on the File System button, then choose CD-ROM.  Increase the "Optimize access pattern for:" option to Quad Speed or Higher.  That may make a difference.

Cheers,

Stu.
Like Bolix said: it's probably the buffersize that is a problem. Most likely he's right about that.
Another thing (this is mentioned before) is the accessing time. You may not forget that the head of your cdrom is lighter than the one of your cdrw. I do not know how much speed difference this will cause but it will make a slight difference. If the head of the drive has to move a lot you will certainly notice it.Because you are reading only one file, much will depend on the compression technique that is used by mpeg 2 (or 4).
One more thing (this might be totally irrelevant): maybe your cdrom can get the cd faster to topspeed than your cdrw.

3408
I think that this is normal. I have a similar thing on my system except that I have an HP8100 CDRW and a Hitachi DVD rom drive.
Main question to as yourself is does the cd-rw make good and reliable discs that your other cd can read, if so no problem, if not then you cd-rw drive may be faulty. Also remember that the 24x speed is an abolutely best case senario.
Another factor might be that your CD-RW is attached to the same drive as your windows swap file and that windows is using swap space during the data transfer from the cd-rw, if the cd-rw is on the same ide channel as the main drive then it might well hiccup during this secondary transfer.
Thanks guys. All good answers. When you say buffer size, are you talking about the buffer size of the cdrom drive, or the ide controller. My original cdrom was pretty inexpensive. wouldn't the new hp 8200 cdr/w have a larger buffer size?
One other thing guys. I went to performance tab - file system-cdrom.
It was set at "no-read ahead"
I thought this should be set at "Quad speed or better" correct?
Read my comment ;)  I suggested that as an option.

Stu.
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Thanks guys. all answers were good. Hard to choose who to award points. Smartgamer's answer was the most direct and satisfying. I realize all other answers are also valid.
Thanks  
SMARTGAMER: Thanks smartgamer. Would this theory apply if i was just watching a single file[mpeg]?
A single mpeg would need to feed continously into the cdrw buffer before channeling through the bus master + processor (and maybe to your memory or swap file). Everyone kinda thinks the access time is stuttering the feed to the buffer.

If you have multiple devices on the same channel (specifically a hard drive) then the problem may related to an inherent drawback of IDE - single device throughput i.e. read from cdrw device -> STOP -> write to swap file/memory/access media player -> STOP -> read mpeg etc.

FYI its a good idea to separate the hd and cdrw onto distinct ide cables/channels or just get scsi a cdrw + scsi hd as its more reliable anyway and allows multiple device throughput per channel (afaik).
Maybe i should have said SWITCH instead of STOP....
Thanks Bolix. I could live with this as long as I know their is nothing wrong with the cdr/w drive. What is your opinion on this.
Is it just a system thing or could the drive be faulyt. i just got it and everything else sems fine i.e recording audio cd etc.
I wish I had some points to give you. Thanks for your help
Bolix. Does the cdr/w drive act differently than the reg. cdrom drive/?
Bolix. Sorry to be a pain, but I would like to figure this out. does your explanation above apply when I am in the middle of viewing the mpeg or only when I initialy acces it. I will figure out a way to get you some points Thanks
You will read information from the cdrom in specific chunks regardless of the size of the mpeg i.e. slow seek/access times apply continously as the file is read from the cdrom sequentially chunk by chunk.
Yes, my theory is corret even in one file, for your average JPEG or other picture, anything, even a TXT, almost always takes up more than one sector.