Date: Mon, 25 Jun 2012 16:19:05 -0700 From: Bit Weasil <bitweasil@...il.com> To: Solar Designer <solar@...nwall.com> Cc: john-dev@...ts.openwall.com Subject: Re: OpenCL kernel max running time vs. "ASIC hang" Yes - that is what I found. My tools have a command-line configurable per-kernel execution time that I use to tune for GUI responsiveness/performance/etc. Typically, I use 50ms for "interactive" GPUs (with X11/Windows/etc running) and 500ms for headless GPUs. On a headless 3x6970 box, I was getting reliable ASIC hangs with 500ms kernels after a while. It would run for 10 minutes or so of 500ms kernels, then hang. Using 50ms kernels, I lose a bit in performance but do not see the ASIC hangs, so for now, I'm considering this a "fix" to the problem. I have not explored where the actual limit is. So the limit is somewhere between 50ms and 500ms. :) On Mon, Jun 25, 2012 at 3:27 PM, Solar Designer <solar@...nwall.com> wrote: > Lukas, myrice, Sayantan, magnum - > > I discussed this matter with Bit Weasil on IRC a few days ago. > According to him, we shouldn't be trying to spend more than 200 ms per > OpenCL kernel invocation, or we'll face random "ASIC hang" issues on AMD > cards (not only on 7970 - in fact, Bit Weasil is playing with 6000 > series cards mostly). Apparently, if a kernel runs fine for 500 ms on > one occasion (or even on 100 occasions in a row), that does not mean it > won't "ASIC hang" on another occasion - but by reducing that to <= 200 ms, > things become reliable. (That's how I understood Bit Weasil.) > > Alexander > Content of type "text/html" skipped
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.