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Hard Dive on Same Channel as DVD

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December 8, 2006 6:04:49 AM

OK, MB has one PATA socket and 4 SATA's.

:?: If HD Master(PATA) and DVD Drive Slave, performance would be terrible - right?

The HD can't be operating/accessed at the same time as the DVD Drive on the same channel?

Looks like new new SATA HD is in order :) 

More about : hard dive channel dvd

December 8, 2006 5:57:10 PM

Someone has given you false info!

Of course you can have your IDE HDD on the far end of the cable as Master, and your DVD unit on the SAME ribbon cable as Slave. Thats why there are 2 connectors on the ribbon cable.

If you later changed your DVD to Master on the far end of the cable, with no Slave, you could then install your HDD(s) as SATA drives on a different Mobo connector.
December 8, 2006 6:15:43 PM

Sure you can attach a CD and hard drive on the same IDE cable. Not sure why you would want to though. Having the CD and hard drive on the same channel will kill your performance. I have had computers go from taking 1 minute to boot to over 7 when you do it that way. For best performance CDs on one IDE cable and hard drives on the other.
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December 8, 2006 6:20:35 PM

Yeah, you don't want to have the DVD drive on the same channel with the hard drive. The DVD drive may be ATA/33 and your hard drive ATA/100 ect. The DVD drive will be the slowest device on the channel and force you hard drive to run at ATA/33 killing performance.
a b G Storage
December 8, 2006 6:27:21 PM

Quote:
Yeah, you don't want to have the DVD drive on the same channel with the hard drive. The DVD drive may be ATA/33 and your hard drive ATA/100 ect. The DVD drive will be the slowest device on the channel and force you hard drive to run at ATA/33 killing performance.


Wrong. First the proof. Now the quote.

Quote:
The ability of an IDE/ATA channel to operate a master and slave device using different transfer modes is called independent device timing. The hard disk controllers integrated on modern chipsets all pretty much support independent timing, as do modern add-in controllers, but this was not always the case. Independent timing can be an issue if, for example, you upgrade an older PC and get a new, high-speed drive, but want to continue to be able to use the older one on the same channel with the new one.


If you look farther down, they talk about "older" being a PIO only transfer device. Modern IDE controllers can run 2 devices at different speeds. (say one ATA100 device, harddrive and one ATA33 device, DVD.) It used to be a problem, it isn't anymore.
December 8, 2006 9:40:48 PM

You can say what you want about slower and faster being able to operate on the same channel but I can hook a hard drive and cd rom up on the same channel on a brand spanking new mother board right now and pretty much guarantee the computer will boot slower. I can't count how many systems I have worked on where this has happened.
December 8, 2006 10:27:27 PM

Quote:
You can say what you want about slower and faster being able to operate on the same channel but I can hook a hard drive and cd rom up on the same channel on a brand spanking new mother board right now and pretty much guarantee the computer will boot slower. I can't count how many systems I have worked on where this has happened.


Sorry, but 4745454b is correct. I've also worked on many systems and as long as the DVD-RW/CD-RW drive is UDMA2 compliant (ATA/33), it can co-exist on the same channel as the hard drive with no loss of performance. Of course, an 80-conductor cable has to be used to support the hard drive's UDMA5 mode, the system BIOS has to be a modern one that recognizes the higher UDMA transfer modes, and the correct Windows chipset drivers must be installed.
December 8, 2006 11:12:40 PM

Quote:
Sorry, but 4745454b is correct. I've also worked on many systems and as long as the DVD-RW/CD-RW drive is UDMA2 compliant (ATA/33), it can co-exist on the same channel as the hard drive with no loss of performance. Of course, an 80-conductor cable has to be used to support the hard drive's UDMA5 mode, the system BIOS has to be a modern one that recognizes the higher UDMA transfer modes, and the correct Windows chipset drivers must be installed.


You can say it all you want but I have seen and timed the hard drive and OS and on the 6 or so motherboard models I work on, put the hard drive on the same channel as the optical drive, 80 conductor cable the system runs slower. I've seen it. The guys I work with have seen it. So for me I still say separate channels for optical and hard drive.
December 8, 2006 11:23:26 PM

In my experience, there was no performance hit for having HD's and CD or DVD drives on the same ribbon. I've had it setup like that on a few machines and I can honestly say, there was no slowdown at all.
I've even tried a few benchmarks a while back to see which configuration gives my the highest transfer rates, I was playing around with master/slave settings, IDE 1 or 2, w/ DVD on the same ribbon, Controller card,different raid arrays, and different strip size for raid 0. Finally settled on the setup I currently have.

I had a lot of time to do this, so I was playing around quite a bit with all the different configurations. IIRC, there was no performance hit for having both on the same ribbon.

I'm not sure if there is a review site that has tested a case like this tho.

HTH.
December 9, 2006 12:49:33 AM

:? I think I will just buy a new SATA HD and not take any chances :)  and sell the PATA HD.

Thanks, guys for your opinions :) 
a b G Storage
December 9, 2006 4:22:30 AM

The only way that would be the case is if you are using an older chipset that didn't support independant transfers, or you are using a much older drive that only works in PIO mode. AFAIK, you still can't mix DMA and PIO devices, it will default both to PIO. (and yes, harddrives don't like PIO...) Again, current chipsets should have no problem doing this. (unless you care to provide a link that claims otherwise)
December 9, 2006 10:55:36 AM

All new stuff. LG or AOpen DVD Burner. Seagate hard drive. Intel motherboard. I've seen the slowdown on 845, 865, 915, 965, 101 and 102 Intel motherboards. After reading all the posts saying it does not matter I would almost not believe it except I have seen the slowdown and used a stopwatch to confirm. One system went from a one minute boot to over seven.

And yes, 80 conductor cable was used.
a b G Storage
December 9, 2006 4:42:53 PM

Sorry, but thats not a link. Did you ever stop to see why the boot time increased? Even if a harddrive is running at ATA33, it should still boot faster then seven minutes. You had a different problem...
December 9, 2006 5:10:40 PM

Check that DMA Mode is enabled on both devices, vs PIO1 or PIO4.

Also check the Application and System Event logs on the PC

Start, Run, eventvwr.msc, [OK]
December 9, 2006 5:32:42 PM

Quote:
Sorry, but thats not a link. Did you ever stop to see why the boot time increased? Even if a harddrive is running at ATA33, it should still boot faster then seven minutes. You had a different problem...


I have no link to prove what myself and the guys I work with have seen with our own eyes. Sorry. I can only offer a quote from the same article you used above.

Hard Disk and ATAPI Device Channel Sharing: There are several reasons why optical drives (or other ATAPI devices) should not be shared on the same channel as a fast hard disk. ATAPI allows the use of the same physical channels as IDE/ATA, but it is not the same protocol; ATAPI uses a much more complicated command structure. Opticals are also generally much slower devices than hard disks, so they can slow a hard disk down when sharing a channel. Finally, some ATAPI devices cannot deal with DMA bus mastering drivers, and will cause a problem if you try to enable bus mastering for a hard disk on a channel they are using.

Seven minutes was on one particular machine. The rest the difference was not as much. Sorry if I led you to believe it was every machine that went from 1 to 7 minutes.

All I am saying is that in my experience any motherboard I have used if I put the hard drive on the same channel as the optical drive the system slows down. All settings were identical before and after the change. The drive was simply moved from by itself on one channel to the other with an optical drive.
a b G Storage
December 9, 2006 5:46:10 PM

Then I'm sorry, but I tend to belive Storagereview. This used to be an issue, but it isn't anymore. As long as DMA is available for both drives, you shouldn't have an issue. I can't vouch for what happened when you tried it, I wasn't there.

My big worry is that your telling people that this will happen when they try it. You could link to many forums I'm sure where people say that it will. The problem is that people haven't updated themselves with this problem. How many more years need to go by before the truth gets out? (actually, I have the feeling that it never will, as people move to SATA, the rumor will die with IDE.)
December 9, 2006 6:16:27 PM

I think I've just solved this one, if it isn't affecting every PC in a group:

Flash the firmware on the Optical drive to the latest version. - :wink:

8) - Tabris:D arkPeace

(If that works, pretty simple fix, eh ?)
December 11, 2006 12:27:40 PM

Quote:
I think I've just solved this one, if it isn't affecting every PC in a group:

Flash the firmware on the Optical drive to the latest version. - :wink:

8) - Tabris:D arkPeace

(If that works, pretty simple fix, eh ?)


It does affect every computer. I only had one that took a crazy amount of time to boot. On the rest while not as noticable there is a difference in speed when both CD and hard drive are on the same channel compared to separate.

Quote:
Then I'm sorry, but I tend to belive Storagereview. This used to be an issue, but it isn't anymore. As long as DMA is available for both drives, you shouldn't have an issue. I can't vouch for what happened when you tried it, I wasn't there.

My big worry is that your telling people that this will happen when they try it. You could link to many forums I'm sure where people say that it will. The problem is that people haven't updated themselves with this problem. How many more years need to go by before the truth gets out? (actually, I have the feeling that it never will, as people move to SATA, the rumor will die with IDE.)


Hey, I believe StorageReview as well. I've read the links, I know the general concensus is that CD and hard drive on the same channel does not cause a performance hit. That said I cannot look at what I have seen and say it does not happen. I can't tell you why, I can offer no proof. Perhaps it has something to do with Intel motherboards, that is all we have used for the last couple of years. But on 845, 865, 915, 101, 102, models, Seagate or Samsung hard drives. LG or AOpen DVD burners, the results follow suit. A subtle but noticable difference in how the computer boots and runs.
Maybe I am just overly sensitive to the performance hit.
a b G Storage
December 11, 2006 3:58:11 PM

Quote:
Maybe I am just overly sensitive to the performance hit.


What I find more likely is that you missed a jumper setting or something else.
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