IBM’s storage announcements are at last upon us, and consensus is growing that the last date we gave for the 3390 disk drive, June 27, will prove to be the right one, although announcements can be pulled right up to the Friday night before they are planned to be made. Look for 22Gb and 15Gb drives using platters of around 10 diameter, attaching solely to 3090 CPUs, and to include functions that mesh with Data Facilty System Managed Storage so that they will only deliver their full capability when DFSMS – which runs only under MVS/ESA – is installed. Access time will be significantly improved, but the data transfer rate will initially be limited to the 4.5Mbytes-per-second of the fastest IBM channels, though 9Mbps and 18Mbps channels are not thought to be far off. The drives will occupy 38% less floor space than the 3380s, and should ship by the end of the third quarter. Before the launch of the disk drives – perhaps next Tuesday, IBM will enhance the 3480 tape drive so that the capacity per cartridge will go up to 1Gb from the present 206Mb, and there are hints of a tape library system that will outdo in every department the Storage Technology product that has been giving IBM such a hard time – but then IBM always says things like that when it is being given a hard time. The company reckons that with the cost per bit of disk storage and controller cache memory set to tumble, top-end users will find less and less need for tape drives, which it expects to fade away. As we have been saying for months, the new disks were due out earlier than this, and were held up by the problematic microcode for the 3990 controller: one of the two key elements is now shipping, and the other is not far behind. Much bigger – but much cheaper – caches will turn up in the controllers. The disk subsystems using clustered drives with 5.25 platters to replace the rest of the 3380 drives are not now likely to appear until next year.
