Frequently Asked Questions Q: What are the different IDE/ATA standards, and which does my server support?A: The different IDE/ATA standards reference the maximum burst transfer rates that the IDE device and IDE controller can support. Burst transfer rate represents the speed that data moves in short periods of time. The normal transfer rate, sometimes called the sustained transfer rate, is normally lower. Both the IDE device and IDE controller must support the same standard to be able to communicate at that speed.
Ultra Direct Memory Access (DMA) allows the transfer of data from the IDE device to memory without processor intervention, allowing for better transfer rates. The various Ultra DMA standards and their maximum burst transfer rates are listed below.
These modes are normally referenced only using their maximum transfer speed, such as Ultra 33, Ultra 66, and so forth.
Note: To use speeds above Ultra 33, a special 80-conductor cable must be used to prevent interference on the cable.
Before DMA, IDE devices used Programmed I/O (PIO) modes to transfer data that was slower than DMA. With PIO, the processor controls the flow of data to and from the IDE device. Below are the different PIO modes and their transfer rates.
The following is a list of Gateway servers and the IDE standards that are supported by those servers.
* The 920 series server has a third IDE controller, which supports up to DMA mode 4 (Ultra 66).