Hi all there, I 'm a Steinberg Cubase user, i've made a search about this info but none found, so here the topic. ? My system: ? OS X 10.9.3 (13D65) Gigabyte GA-Z77-UD3H 3,4 GHz Intel Core i5 8Gb DDR3 1.600MHz STEINBERG MIDEX 3 - USB MIDI interface connected to an USB2.0 port. ? On system definitions, the Midi interface is just reported as "Composite device" ? Product ID: 0x1101 ? Vendor ID: 0x0a4e? (Steinberg Soft-und Hardware GmbH) ? Version: 1.02 ? Speed: Fino a 12 Mb/sec ? ID position: 0x1a150000 / 7 ? Corrente disponibile (mA): 500 ? Corrente necessaria (mA): 250 ?The issue: I always used my Steinberg Midex 3 Usb card to manage MIDI in and out from the sequencer and it works flawless under windows XP sp3, then, an upgrade to a new PC with better performances with an i5 Cpu with windows 7 started my troubles, tried the Hackintosh way, but nope, issue is still the same. ? ? MIDI timings are just awful. The simplest test made with just a loopback OUT>IN gives terrible results, notes positions and their lengths are just widely approximated. This makes the system totally unusable for musical purposes, of course. I've found another basic USB MIDI Interface, and EDIROL (ROLAND) UM1SX, but issues are just the same as the MIDEX. ? Now, hanging around the net, i've found that i'm not the only one with this issue. ? Statements Found: - USB 3.0 ports on Macs aren't too compatible with USB 1.1 or powered USB 2.0 old interfaces. - Could be an IRQ conflict with?HPET ( which asks 4 ports?randomly) on DSDT - Have to buy an old Emagic USB?Midi card that works (about 200 € used) ? Already tried: - On BIOS, switch ON/OFF legacy modes, USB2.0 controllers, AHCI, EHCI emulations on USB menus, Nope. - DSDTSE edit, but it's way too difficult without a step by step tutorial ? Any idea? Thank you. ? ?