As usual, xkcd knocks it out of the park. [ ](http://xkcd.com/1168/) I talked about qualifications for our SE position. The ability to talk customers through complex vi-based configuration sessions for system files, while driving 70 mph on the freeway, is a hard requirement. Not quite a munition defusing effort, but close enough. Unfortunately in something like the game of telephone, what I originally wrote was … transmogrified … into something very different.

So I was sick of the crashes in the NVidia driver. Nouveau wasn’t that good. Maybe someday it will be, but its really not that useful to me. So I opted for an ATI W5000 card. Initial install was rocky. The card used VESA drivers, and that was fine for initial boot. Accelerated drivers … didn’t. They were slower than the VESA drivers. Window movements were jerky. It felt … wrong … somehow.

Ok, this was fun. Its been a while since I dusted off good old rzf … ok, its been 12-ish days … but I really have been wanting to try recoding it in javascript. As you might (or might not) remember, I asked questions (a very long time ago) about quality of generated code from a few different C compilers (and eventually the same code in Fortran). I rewote inner loops to hand optimize the compilation, and then recoded as SSE2.

This past December, 1 year to the day, and in fact, the very hour my wife was waking up from her surgery, we were at a Trans Siberian Orchestra concert. I like TSO quite a bit, and this had serious significance for us. Like the XKCD biopsiversary, this was our own little F-U to cancer. Not directly related to this, they played a rearranged version of a song on their newer CD.

See the Systems Engineering position here, and the System Build Technician position here. I’ll get these up on the InsideHPC.com site and a few others soon (tomorrow). But they are open now. For the Systems Engineering position, we really need someone in NYC area with a strong financial services background … Doug made me take out the “able to leap tall buildings in a single bound” line, as well as the “must be able to talk customers through complex vi sessions on system configuration files while driving 70 mph on a highway.

Oh yes we did. Oh yes. We did. This is the fastest storage box we are aware of, in market. This is so far outside of ram, and outside of OS and RAID level cache … [root@siFlash ~]# fio srt.fio ... Run status group 0 (all jobs): READ: io=786432MB, aggrb=23971MB/s, minb=23971MB/s, maxb=23971MB/s, mint=32808msec, maxt=32808msec This is 1TB read in 40 seconds or so. 1PB read in 40k seconds (1/2 a day).

… buying a non-NVidia GPU product. Specifically the ATI FirePro W5000 for my desktop. I need to see if this is any more stable than the NVidia GTX series products. Feedback from customers running various flavors of Fermi, Kepler, Tesla, … suggest that the problem that was reported to me, that I’ve run into, is fairly wide spread. It looks like a particular version of the driver (295.33) may not trip this problem.

I’ve been having a problem with a newly installed Mint 14 machine. A customer has been having this problem with a Scientific Linux 6.x machine. Some time after lighting up the machine, and usually after using an OpenGL application, the NVidia driver effectively hard locks, dumping error messages like this into the system logs. [ 5444.863396] NVRM: Xid (0000:85:00): 13, 0003 00000000 00000000 00000ff4 0f000000 00000000 [ 5444.867446] NVRM: Xid (0000:85:00): 9, Channel 00000003 Instance 00000000 Intr 00000010 [ 5444.

I finally took some time from a busy schedule to play with AVX. I took my trusty old rzf code (Riemann Zeta function) and rewrote the time expensive inner loop in AVX primatives hooked to my C code. As a reminder, this code is a very simple sum reduction, and can be trivially parallelized (sum reduction). Vectorization isn’t as straightforward, and I found that compiler auto-vectorization doesn’t work well for it.

I’ve talked about precision in previous posts quite a while ago. I had seen some interesting posts about Javascript, which suggested that it was not immune to the same issues … if anything it was as problematic as most other languages, and maybe had a little less “guarding” the programmer against potential failure modes. This is not a terrible problem, I just found it amusing. Understand that I actually like Javascript.