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IDE Hard Drive and DVD Rom on the same cable?
- Thread starter dexterdoo
- Start date
rclarke250
Technical User
It will not effect the speed so you will notice. If you were to go with a sata hard drive of current manufacture, you would notice it, but how much would depend on how old your ide hdd is. Since you don't give us the model numbers of the devices, and if you are using an high speed 80 pin ide cable, or standard 40 pin cable, it's all guess work.
hairlessupportmonkey
IS-IT--Management
the rule is the bus speed will run at the slowest device on the cable, and depending on your hardware, normally the CD/DVD has a slower bus speed to the HDD.
ACSS - SME
General Geek
ACSS - SME
General Geek
HSM,
this NO LONGER holds true... todays chipsets that control the EIDE/ATAPI controllers, use what is called "independent device timing", with that each individual device is timed differently, thus allowing the combination of TWO different speeds, e.g. an UDMA2 (Ultra-ATA/33) and UDMA4+ (Ultra-ATA/66+), both will run at their respective speeds...
BUT:
CD/DVD's are not EIDE they are ATAPI, even though they do use the same physical connectors and cables, they do operate differently and use a different protocal... some ODDs (Optical Disk Drives) do not play well with UDMA devices on the same channel and can get confused...
also it should be noted, that Windows XP sometimes goes bonkers when the ODD is NOT on the secondary channel (seen it)...
so what are the options for the OP:
1. install both devices on the single channel, jumpering the HDD as master and the ODD as slave...
2- buy a cheap EIDE controller (I think they go for around $10 to $15), and attach the ODD to said controller...
3. buy either a SATA HDD or ODD, less of a problem if it is the ODD that gets replaced (no drivers are needed, where as for the HDD drivers may be needed if the mainboard does not allow setting the HDD to IDE, in case of cloning the drive over to SATA)...
PS: I found the following site (it's OLD but the information is still valid) to very helpful in understanding the IDE/EIDE/ATAPI etc.
Ben
"If it works don't fix it! If it doesn't use a sledgehammer..."
How to ask a question, when posting them to a professional forum.
Only ask questions with yes/no answers if you want "yes" or "no"
this NO LONGER holds true... todays chipsets that control the EIDE/ATAPI controllers, use what is called "independent device timing", with that each individual device is timed differently, thus allowing the combination of TWO different speeds, e.g. an UDMA2 (Ultra-ATA/33) and UDMA4+ (Ultra-ATA/66+), both will run at their respective speeds...
BUT:
CD/DVD's are not EIDE they are ATAPI, even though they do use the same physical connectors and cables, they do operate differently and use a different protocal... some ODDs (Optical Disk Drives) do not play well with UDMA devices on the same channel and can get confused...
also it should be noted, that Windows XP sometimes goes bonkers when the ODD is NOT on the secondary channel (seen it)...
so what are the options for the OP:
1. install both devices on the single channel, jumpering the HDD as master and the ODD as slave...
2- buy a cheap EIDE controller (I think they go for around $10 to $15), and attach the ODD to said controller...
3. buy either a SATA HDD or ODD, less of a problem if it is the ODD that gets replaced (no drivers are needed, where as for the HDD drivers may be needed if the mainboard does not allow setting the HDD to IDE, in case of cloning the drive over to SATA)...
PS: I found the following site (it's OLD but the information is still valid) to very helpful in understanding the IDE/EIDE/ATAPI etc.
Ben
"If it works don't fix it! If it doesn't use a sledgehammer..."
How to ask a question, when posting them to a professional forum.
Only ask questions with yes/no answers if you want "yes" or "no"
rclarke250
Technical User
Taken from the wiki.
Two devices on one cable — speed impact
There are many debates about how much a slow device can impact the performance of a faster device on the same cable. There is an effect, but the debate is confused by the blurring of two quite different causes, called here "Lowest speed" and "One operation at a time".
[edit] "Lowest speed"
It is a common misconception that, if two devices of different speed capabilities are on the same cable, both devices' data transfers will be constrained to the speed of the slower device.
For all modern ATA host adapters this is not true, as modern ATA host adapters support independent device timing. This allows each device on the cable to transfer data at its own best speed. Even with older adapters without independent timing, this effect only applies to the data transfer phase of a read or write operation. This is usually the shortest part of a complete read or write operation.[23]
[edit] "One operation at a time"
This is caused by the omission of both overlapped and queued feature sets from most parallel ATA products. Only one device on a cable can perform a read or write operation at one time, therefore a fast device on the same cable as a slow device under heavy use will find it has to wait for the slow device to complete its task first.
However, most modern devices will report write operations as complete once the data is stored in its onboard cache memory, before the data is written to the (slow) magnetic storage. This allows commands to be sent to the other device on the cable, reducing the impact of the "one operation at a time" limit.
The impact of this on a system's performance depends on the application. For example, when copying data from an optical drive to a hard drive (such as during software installation), this effect probably doesn't matter: Such jobs are necessarily limited by the speed of the optical drive no matter where it is. But if the hard drive in question is also expected to provide good throughput for other tasks at the same time, it probably should not be on the same cable as the optical drive.
That being said, If it were me, I'd buy a new sata DVD, they can be had from Newegg for about $20 free shipping. Cable about $3 or by a retail kit that has the cable, OEM does not. At least until hdd prices come down. But unless you are burning a disc, the same time you are hitting the hdd hard, there will be negligible speed impact on a normal day to day use unless you are a gamer, but then why are you still using IDE for any devices. And if you are going to mix types on the same cable, never choose CS, always set the hdd as Master, the odd as slave.
Two devices on one cable — speed impact
There are many debates about how much a slow device can impact the performance of a faster device on the same cable. There is an effect, but the debate is confused by the blurring of two quite different causes, called here "Lowest speed" and "One operation at a time".
[edit] "Lowest speed"
It is a common misconception that, if two devices of different speed capabilities are on the same cable, both devices' data transfers will be constrained to the speed of the slower device.
For all modern ATA host adapters this is not true, as modern ATA host adapters support independent device timing. This allows each device on the cable to transfer data at its own best speed. Even with older adapters without independent timing, this effect only applies to the data transfer phase of a read or write operation. This is usually the shortest part of a complete read or write operation.[23]
[edit] "One operation at a time"
This is caused by the omission of both overlapped and queued feature sets from most parallel ATA products. Only one device on a cable can perform a read or write operation at one time, therefore a fast device on the same cable as a slow device under heavy use will find it has to wait for the slow device to complete its task first.
However, most modern devices will report write operations as complete once the data is stored in its onboard cache memory, before the data is written to the (slow) magnetic storage. This allows commands to be sent to the other device on the cable, reducing the impact of the "one operation at a time" limit.
The impact of this on a system's performance depends on the application. For example, when copying data from an optical drive to a hard drive (such as during software installation), this effect probably doesn't matter: Such jobs are necessarily limited by the speed of the optical drive no matter where it is. But if the hard drive in question is also expected to provide good throughput for other tasks at the same time, it probably should not be on the same cable as the optical drive.
That being said, If it were me, I'd buy a new sata DVD, they can be had from Newegg for about $20 free shipping. Cable about $3 or by a retail kit that has the cable, OEM does not. At least until hdd prices come down. But unless you are burning a disc, the same time you are hitting the hdd hard, there will be negligible speed impact on a normal day to day use unless you are a gamer, but then why are you still using IDE for any devices. And if you are going to mix types on the same cable, never choose CS, always set the hdd as Master, the odd as slave.
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