UK IBM mainframe users are part-exchanging their old 3090s for the new E-models rather than upgrading them, according to leasing company Econocom UK. In its latest quarterly guide to the IBM market, Econocom says that box swapping is far more attractive than upgrading non-Es with the prevailing level of discounts and deferred payments on offer from IBM. As a result, it forecasts, many 3090s will become available on the second-hand market during the latter part of this year. Lower down the scale, prices for used 3084s, 3083-JXs and 3081-KXs are holding steady while other 3083s, 3081s and old 4300s are falling in value. Econocom recommends that users of old 4321s, 31s, 41s and 61s who want to upgrade to the new 4381 models 21 to 24 should ask IBM for the full 10% discount on offer on the new machines and sell their existing box to a lessor or broker such as Econocom. Econocom has also noted a 20% cut in 4381 memory board prices from IBM, but this has been more than matched by EMC Corp, which early last week cut its US prices for 8Mb of main storage by 25% to $30,000. UK prices are expected to fall in line. On peripherals, Econocom says the AA4 and BO4 3380 disk drives are now available in vast quantities as users replace them with the double density E boxes. The cost of upgrading a D to an E is now just over UKP27,000 but Econocom believes that customers can get better value from installing second-hand 3375 and 3370 thin film drives which are currently selling at between 11 and 18% of their official IBM list prices. Econocom also suggests than users of System/36s who want to upgrade to D models should go in for a box swap rather than wait until the end of the year – and US machines converted for European power are available on four weeks’ delivery.