Mixing hard drives

[belveder 0]

Out of curiosity, I just bought a new hard drive that is 80 gig, 7200 rpm, ATA 100 with 8mg cache but my old hard drive is 30 gig, ATA 66 and runs at 5400 rpm. I would like to run both (preferably with the OS on the older, smaller one) but I read somewhere once that you can't. I read somewhere else though that the new drive should be on one IDE cable with the cdrom as slave and the old on another IDE cable with a burner as slave. But if the old drive is lower ATA and RPM that the new one won't the new drive slow down to the capabilites of the old? Also, wouldn't that affect burning separating the cdrom from the burner?

 

 

My system is only a Celeron 850 with 640 mg ram on an AOpen mobo

 

Can someone please tell me if you can or can't mix the drives? And if so, will having the cdrom & burner affect burning?

 

Thanks in advance

[jimf43 0]

I'd certainly want the OS on the faster of the two drives, but, their is certainly no reason why you can't run two different spec drives .

 

The only requirements are as follows:

 

* On each IDE channel, one drive must be set to master and the other should be set to slave.

 

* On the IDE cable drive 0 should be attached to the center connection, drive 1 should be attached to the end.

 

* It's It's a good idea to put Hard Drives on channel 0 and CDs on channel 1 (but, it's arguably that this is technically unnecessary).

 

* All CDs should be set as DNA enabled in the bios

[belveder 0]

Thanks for that, but can you clear up something for me please. You say to put drive 0 on the centre of the cable, I presume you mean the Master and the Slave (the older, slower drive) at the end?

 

Does having the older HD connected at all slow down the new HD or isn't it noticeable?

 

Thanks again

[jimf43 0]

Quote:

Thanks for that, but can you clear up something for me please. You say to put drive 0 on the centre of the cable, I presume you mean the Master and the Slave (the older, slower drive) at the end?

0=master, 1=slave

Quote:

Does having the older HD connected at all slow down the new HD or isn't it noticeable?

No difference.

[belveder 0]

Thanks for that, I'll try it out and see what happens

[Bursar 0]

With an ATA100 cable, the blue connector goes to the motherboard, the master drive on the end on the cable (with the black connector) and the slave goes in the middle (to the grey connector).

 

Not sure what happens if you change these things around (which is what jimf43 is suggesting), but what I've written above is the 'proper' way of doing it.

[belveder 0]

ok, thanks

[jimf43 0]

Quote:

With an ATA100 cable, the blue connector goes to the motherboard, the master drive on the end on the cable (with the black connector) and the slave goes in the middle (to the grey connector).

Not sure what happens if you change these things around (which is what jimf43 is suggesting), but what I've written above is the 'proper' way of doing it.

This is confusing to say the least. I apologize to all, but my documentation
from Liteon, and Mitzumi both give the center cable connection as Master device.
Obviously, the is wrong, as WD and Maxtor both list the end (black) connection
as being master, and, the center (grey) as slave... see here:
http://www.wdc.com/library/eide/2779-001001-012.pdf
and here:
http://maxtor.custhelp.com/cgi-bin/maxto...lPTE*&p_li=

I thought that the discrepancies might be between the 33/66 cable, and the
100/133 cable, but the documentation from Liteon, and Mitzumi is pretty
new, so I'm at a loss, and more than a little angry too.

[Champion_R 0]

Blue is board, Black is Primary and Grey Secondary if memory serves me correctly.

 

In an ideal world, I like to keep all my magnetic drivs on separate channels to allow faster trasnfer between them. My 20GB shares a channel with my CDROM and the 20GB drive takes no performence hit.

[belveder 0]

It seems like we are stuck on the same question though, will it slow down the faster drive to the slower drives speed? lol

[Bursar 0]

For the speed thing, I was under the impression that things would slow down if you mix older ATA 33/66 drives with ATA100 drives, but I was informed on this very forum that such problems were fixed in the ATA standard quite some time ago.

 

Hope that helps.

 

As for the colour coding on the IDE cables, I've just checked several websites and the manuals for a couple of motherboards that I have here, and they all say the master drive is connected to the black connector.

 

Champion also agrees with me. Who should know better now eh?

[belveder 0]

If it does slow down the newer hard drive, would I be right to presume that the difference in speed would barely be noticeable on my computer seeing that it is only an 850?

[duhmez 0]

Does a cdrom slow down a HD ont jhe same channel, when the cd rom is not being used? Like idle?

 

I would not hink that it would as it should not be sending out any requests when its not doing anything............

 

This is one thing ive been wondering for a very long time.

 

If it only slows down when reading from the cd, then I dont care as Id rather have fastt file transfers between my ide disks. I never want my IDE disks mastered and slaved.

[Bursar 0]

Well the reason I asked was because I was adding a CD-RW drive and was curious about the best way to hook everything up.

 

I know that previously connecting an ATA66 and an ATA100 device would cause both drives to run at ATA66 speed.

 

As I said, I was told here that that problem was fixed in the ATA standard. I don't know if it's true, it's just what I was told.

 

Aha, just found something:

Quote:

Connector Assignments and Color Coding: For the first time, the 80-conductor cable defines specific roles for each of the connectors on the cable; the older cable did not. Color coding of the connectors is used to make it easier to determine which connector goes with each device:

Blue: The blue connector attaches to the host (motherboard or controller).

Gray: The gray connector is in the middle of the cable, and goes to any slave (device 1) drive if present on the channel.

Black: The black connector is at the opposite end from the host connector and goes to the master drive (device 0), or a single drive if only one is used.

 

There are a couple of reasons why this coding was done. It is not a good idea to connect a single drive to the middle connector on a ribbon cable, because the "stub" of left-over, unconnected cable causes signaling problems. With Ultra DMA this "stub" connection is not just "not recommended", it is illegal: a single device must be at the end of the cable. The other reason is that since these cables support cable select inherently, the position of each drive on the cable matters if cable select is being used. With these two needs combined, it just made sense to design the cable so that drive positioning was explicitly clear.

 

Independent Master/Slave Device Timing: Hard disk controllers on modern systems support running the master and slave device at different speeds, if one supports faster transfer modes than the other. Some systems, however, especially older ones, do not. If you are using two devices with radically different maximum transfer rates, and the chipset doesn't support independent timing, you will slow down the faster device to the speed of the slower one.

 

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 your system does not support independent device timing, and you use a newer hard disk that supports PIO mode 4 on the same channel as an older hard disk that operates only at PIO mode 0, the system will knock down the PIO mode to 0 for both drives. This will hamper the performance of the newer hard disk. The lack of independent device timing on many older systems is one reason why placing ATAPI devices like CD-ROMs on the same channel as a fast hard disk is usually not recommended. (It should be pointed out that we are talking here about the interface or external transfer speed of these devices. Reducing the speed of the interface only causes big issues if the effective interface speed becomes less than the sustained transfer rate of the disk. For a full discussion of these issues, please see this page.)

 

Again, today's chipsets all pretty much support independent timing, so this is less of an issue than it once was.

Hope that clears it up for everyone

[jimf43 0]

I thought that when they fixed the problem with placing a cd/cdr on the same channel as a HD, that, they also gave the IDE chips enough smarts to negotiate different HD speeds too. Again, I'm finding a lot of sources that contradict each other on this... There seem to be no 'Experts' :x

 

If you want to be safe, then, I'd guess that you want to put one HD on each channel, since, you don't want that faster HD to be running any slower. At this point, I wish I had a different ATA HD around, so I could test this all myself ;(

[belveder 0]

I now what you mean about different and conflicting answers, I have posted this question in a couple forums plus read around the place, and there doesn't seem to be a set answer although it does seem to sway towards

 

New drive = Master

CdRom = Slave

 

Old Drive = Master

Burner = Slave

 

Even though having the two cd's on separate cables makes burning slower lol