I'm a bit stumped by this one. I have a Titan Z that's locking up under SLI gaming loads. The symptoms are (all Windows 10 1709): 1) Hard locks (no BSOD, have to reset) under the latest 391.35 drivers after a minute or two of Unigine Heaven. 2) Runs Unigine Heaven for hours in single GPU mode with 391.35. 3) Runs Unigine Heaven for hours in SLI mode with older 382.33 drivers. So it must be a driver issue with SLI, right? Except the same machine with 2x Titan Blacks in SLI can run Unigine Heaven for hours under the newest 391.35 drivers, and the Titan Z is basically a couple of Titan Blacks on a stick. Overall I don't much care if Unigine Heaven crashes, as I'm using these for DP compute. However I'm worried that the 391.35 drivers might be exposing some kind of hardware fault in the Titan Z, and I'd rather figure out what's going on now than have to troubleshoot crashy code due to flaky hardware later on. Nvidia support has been pretty useless so far, their latest suggestion was to try the Titan Z in different PCIe slots (which predictably changed nothing). Anyone have any thoughts or tests I might run to figure out if this is a software or hardware issue?