Date: Sun, 21 Jun 2015 01:30:52 +0200 From: magnum <john.magnum@...hmail.com> To: john-dev@...ts.openwall.com Subject: Re: bcrypt-opencl local vs. private memory On 2015-06-20 23:04, Solar Designer wrote: > magnum, Sayantan - > > On Tue, Jun 16, 2015 at 05:06:40PM +0300, Solar Designer wrote: >> Sayantan took care of this at the time, in commit >> 97545b7ab51a4e8ddccba1a098f5448d808ae39b which includes: >> >> #if gpu_nvidia(DEVICE_INFO) >> #define MAYBE_LOCAL __private >> #else >> #define MAYBE_LOCAL __local >> #endif >> >> I've just tested this on our GTX 570 as well, and unfortunately it >> actually hurts performance there. (Even though it was helping on our >> TITAN a bit.) With the above commit, I am getting around 400 c/s. >> With forced use of __local, it's around 1200 c/s. >> >> I merely want to document this in here. I am not suggesting making any >> further change yet. Either of these speeds is quite low anyway. >> >> I am currently discussing bcrypt on GPU with Alain (via off-list >> e-mail), who managed to achieve much higher speeds anyway, including on >> his GTX 590 (per GPU). > > (Un)fortunately, Alain's initial results that I mentioned above were > wrong. So no "much higher speeds" for us. I think we need to fix the > original issue described above somehow. magnum, can we possibly have > this local vs. private bit autodetected along with GWS and LWS? Well the bcrypt format could do so. That would be for Sayantan to implement. However, I just commited a workaround for now, simply using nvidia_sm_5x() instead of gpu_nvidia(). BTW for my Kepler GPU, I see no difference between using local or private. magnum
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.