The difference between a disk drive and a drum drive is geometry, not speed. A drum with moving heads, e.g., UNIVAC FastRand, is as slow as a disk with moving heads.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <[email protected]> on behalf of John McKown <[email protected]> Sent: Wednesday, December 20, 2017 8:08 AM To: [email protected] Subject: Can anyone remember "drum" storage? It's not really a drum, but it is getting closer. Of course, for true speed, one should go SSD. http://secure-web.cisco.com/14Go7ABDbjk9VThaC4sdbSdHzTz-A0KlrF-hyjgLFWoWWzkAzhXcyzC_cjHNP1gE-mHQ8VZ9ZMwB8RnVFtQMhxXjY-Fi-ozyLEBsuEYYxaPuPUu0d79W_eFl_O1i1Iohh8kPwXGF2vPBe2pnWW4dA-CDz8AY4oEqXyEPQzJk_CDOgkAFV1wErK9MuR5p7MVMswjmI_x9C-OBpYOivsvuqprW4uXtjvn691sI2gtRoMKvjQQcFAX4BnjHSe1Bkbq_IDwHblW7DsWbzml_N54li2blj1u2EjWR0SV_kupLakWdHPptQEXznXiu3qNXx5tZ_nkr80ow-dJ3ceIDxEspTwQAXRDujfeUZ1s_Yd_-xt9ZTP--6a0PJzcyndsmL2r-rbX1wYpUDQ9774fGfjyJWAFRkHGbxWLbPz9_XgJDmXxWsDIRTzUCfZcx_76eva4X5/http%3A%2F%2Fwww.theregister.co.uk%2F2017%2F12%2F19%2Fseagate_disk_drive_multi_actuator%2F [quote] Seagate is increasing IO performance in disk drives by separating read-write heads into two separate sets which can operate independently and in parallel. The heads are positioned at one end of actuator arms which rotate around a post at their other end to move the heads across the platter surfaces. Thus, with an eight-platter drive, each read-write head is positioned above the same cylindrical track on each platter and reads or writes to and from the same disk blocks on each platter's surface. [\quote] -- I have a theory that it's impossible to prove anything, but I can't prove it. Maranatha! <>< John McKown ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
