RPM question

I think after someone answer my question it should be put in the HDD FAQ

Question1: rpm will having 2 different speed rpm HDD ont he same ribbon slow down the faster HDD? aka 7200 rpm and 5400 rpm?

Question2: Is it better to have a cd-rom/HDD combo on a ribbon than a 5400rpm/7200rpm combo on a ribbon?

thanks

Q 1) no, unless it’s in RAID then all the drives will share the weakest attributes like (rpm speed and size and even bus speeds)
Q2) that would depend on what you’re using the drives for like ex) HDD1 and CD1 on one ribbon the other HDD2 if you copy data from CD1 to HDD1 it will get slowed down as only one operation at a time can be done on that IDE but if you sent the data over to IDE with HDD2 on it, it would run at full bus speed for the slower drive

I will elaborate a little bit on the last post....

Most CD-Rom's have a max transfer speed of ATA/33 (UDMA Mode 2). Therefore if you pair a hard drive with a CD-ROM on the same channel the maximum host speed on that channel will be ATA/33.

Subsequently it is not advisable to pair a CD-ROM drive with a hard drive, unless speed of the hard drive is less of a concern (i.e a drive used primarily for storing bulk data, MP3's videos etc).

Same goes for the 5400rpm / 7200rpm. If the 5400 RPM is only ATA/66 and the 7200 is ATA/100 you will be limited to a host transfer of 66MBps. If both drives happen to be ATA100 you will be fine.

As stated before... two drives cannot transfer simutaneously when paired on the same channel.