Andrea presents our paper on how to achieve bitwise reproducibility for floating point arithmetic on any architecture for cheap (nearly free). See more details in the paper.
May232014
May232014
Andrea presents our paper on how to achieve bitwise reproducibility for floating point arithmetic on any architecture for cheap (nearly free). See more details in the paper.
May102014
So we did it again, we celebrated Greg’s, Maciej’s, and Bogdan’s recent successes with a barbecue. But we were not SPCL if it was any barbecue … of course it was at the top of a mountain, this time the “Grosse Mythen”.
Remember v1.0 to Mount Rigi? Switzerland is absolutely awesome! Mountains, everything is green, ETH :-).
Here are some impressions:
The complete tour was 6.9 kms a total walking time of 3.35 hours and an altitude difference of only 750m (from 1149m to 1899m). Much shorter and less altitude then our last trip. But not less fun! And yes, my GPS was a bit off :-/.
So this is how it looked from the start — I have to say pretty impressive. But it turned out to be much much simpler than it seems, and MUCH simpler than Rigi was :-).
Do you see the flag on top (yeah, it’s the red pixel on the right side in this resolution)? That’s where we’ll hike!
Our first real view towards Brunni.
The path is actually at the beginning a bit more stressful than later but overall simple.
Lots of planes around Mythen, some seem rather historic, like this one.
First stage done — arrived at Holzegg and view down to Brunni (yeah, we could have taken the cable car but are we men or what?). SPCLers walk up mountains!
Now the steep part begins, it’s actually a bit dangerous — many places where you can fall a couple of 100 meters :-).
Mac still looks too good … we should have taken more water and food :-). Remember Rigi?
The path is basically vertically (in serpentines) up a rock wall. Nice! You should not be afraid of height …
… because you will constantly see beautiful things like this …
… or horror abysses right at the trail like this :-).
But there were helpers, these nice chains probably saved out life more than once.
Mac acquired a second backpack and some stones on the way … and he’s still looking too good!
A nice bench … again, for people not afraid of height.
The neighboring “Kleiner Mythen” is apparently much harder to climb. And it’s smaller, so why would we climb it anyway!? 😉
The path – awesome! Walking a nice and thin ridge.
And again, some nice opportunities to fly, aehem fall.
Still snow around the top in May.
The top – we made it! Most importantly: the Swiss flag :-).
The last ascent to the very top … still looking too fresh!
We all made it to the top alive (and later back down).
Relaxing with a beer … tststs.
Meanwhile food preparations start.
The grill didn’t start that well … we should have sent smoke signals down to the valley ;-).
Some folks took shifts in blowing.
We brought some nice food … to the nice view!
To avoid fights with the locals!
Finally the grill started … took 30 mins or so ;-).
Beautiful views, did I mention that it was rather high?
But most beautiful views — Rigi was just left of this.
And of course, if you travel with a Polak, you’ll get some top-vodka.
The car was waiting patently in Brunni.
Many opportunities for free falls :-).
I drove, and we made some contact with cows :-).
Others took the bus back home.
After all, *awesome* and very efficient, the whole tour took 7.5 hours :-). So we set some new standards for the SPCL hike v 3.0!
Jan262014
This year, I attended my first HiPEAC conference. We had a paper at the main track. It was in Vienna and thus really easy to reach (1 hour by plane). I actually thought about commuting from Zurich every day.
Bogdan presented the paper and did a very good job! I received several positive comments afterwards. Kudos Bogdan!
Dec22013
Supercomputing is the premier conference in high performance and parallel computing. With more than 10,000 attendees, it’s also the largest and highest-impact conference in the field. Literally everybody is there. Torsten summarized the role of the conference in a blog poster over at CACM.
SPCL had a great year at Supercomputing 2013 (SC13)! We’ve been involved in multiple elements of the technical program:
Here are some impressions:
Impressions from the Emerging Technologies Booth
Impressions from the Emerging Technologies Booth
Impressions from the Emerging Technologies Booth
Impressions from the Emerging Technologies Booth
Emerging Technology Booth Talks were generally well attended!
Maciej and his session chair (Rajeev Thakur) are preparing for the presentation of our best paper candidate.
The large room was packed (this shows only the right half, left was as full).
Robert and Maciej fielding questions.
Robert presenting his poster … unfortunately, Maciej didn’t take a picture of Aditya and his poster which was upstairs (and looked at least as good :-)).
Torsten releasing the 2nd Green Graph 500 list with surprises in the top ranks!
The SC13 Best Paper team and presentation!
Torsten receives his “Young Achievers in Scalable Computing” Award.
Torsten receives his “Young Achievers in Scalable Computing” Award.
Robert received the ACM SRC Bronze medal.
All in all – a great success! Congrats and thanks to everyone who contributed!
Some more nice pictures can be found here.
Nov102013
Today I typed the last command on my long-running server (serving www.unixer.de since 2006 until yesterday):
benten ~ $ uptime 01:31:47 up 676 days, 16:20, 5 users, load average: 2.08, 1.42, 1.39 benten ~ $ dd if=/dev/zero of=/dev/hda & benten ~ $ dd if=/dev/zero of=/dev/hdb & benten ~ $ dd if=/dev/zero of=/dev/hdc &
This machine was an old decommissioned cluster node (well, a result of
combining two half-working nodes) and served me since 2006 (seven
years!) very well. Today, it was shut off.
It’s nearly historic (single-core!):
benten ~ $ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 15 model : 1 model name : Intel(R) Pentium(R) 4 CPU 1.50GHz stepping : 2 cpu MHz : 1495.230 cache size : 256 KB fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 2 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi m mx fxsr sse sse2 ss ht tm up pebs bts bogomips : 2995.24 clflush size : 64 power management: benten ~ $ free total used free shared buffers cached Mem: 775932 766372 9560 0 85720 273792 -/+ buffers/cache: 406860 369072 Swap: 975200 57904 917296 benten ~ $ fdisk -l Disk /dev/hda: 20.0 GB, 20020396032 bytes Disk /dev/hdb: 500.1 GB, 500107862016 bytes Disk /dev/hdc: 80.0 GB, 80026361856 bytes Disk /dev/hdd: 500.1 GB, 500107862016 bytes benten ~ $ cat /proc/mdstat Personalities : [raid1] md0 : active raid1 hdb1[0] hdd1[2](F) 488383936 blocks [2/1] [U_]
Jul282013
Since the lab moved to Switzerland, we decided to do a hiking trip in the pre-alps. It’s incredibly beautiful and efficient (only 30 mins by car :-)). We decided to climb mount Rigi wit Timo, Maciej, Tobias, and Natalia. Maciej, our local mountaineer, heroically volunteered to carry all food up :-). Unfortunately, we picked a very hot day (about 35 Celsius). It was of course painful but a lot of fun at the same time :-). Rigi is amazing and Switzerland is absolutely beautiful!
Here are some impressions of our first lab excursion.
This is our complete trip from top to bottom. More than 1km height difference on about 13 kms. Time to go up ~3:30hrs, time to go down 3:45hrs. Here are some more detailed stats pdf
Before we start! We still look fine 🙂
The first sign, btw., Swiss signage is generally horrible. Rigi is ok, we also had multiple cell phones and even multiple Internet connections :-).
Mac carrying all the stuff, still smiling :-).
First nice view at a lame altitude.
Getting better ….
First hut, still lame altitude. People are having beers here, so can’t be too hard!
Tracking …
And the path vanished somewhat :-/.
Better views.
Strange upwards path (rather steep).
Yes, Mac is alive.
Even better views, we gained some altitude.
Find Mac
Find Mac (easier)
Resti, 1198 meters.
Nice view (and find Mac)
Lame people take the train …
More views.
First rest – nice shade!
Timo doing well (with his new hat)
Water 🙂
Maybe a bit too much.
The whole path was full of barbed wire … it’ll entangle you and rescue you if you fall down :-).
Yes, even at tight passages … a bit weird.
Discussing animals :-).
Some locals.
Birds coming rather close. I didn’t have the energy to get the good lens out of the bag, sorry!
More views. The right one could be our next target!
The top … 3hrs upstairs.
And then the lame surprise … completely commercialized, a train station and tons of overweight tourists. Btw., we saw *NOBODY* walking up even though we moved slowly. Some people were coming down but they looked way too fresh (they must have taken the train up).
The train.
Very nice unobstructed views towards Germany.
Lake Zug (I think).
The alps (more hiking!).
Timo found a friend.
Love at first sight (look at the ears).
Our new lab member, donk.
Yes, we made it!
Military drill to pass electrified fences :-).
Views ….
More locals watching us.
Our hickory fridge. So it was 35 Celsius and we walked for four hours or more. How do you prevent your barbecue meat from going bad? Well, Mac had the rescuing idea: deep-freeze everything and pack six bottles of frozen water into a thermo-bag. It lasted very well, all meat was still slightly frozen. Even better, we had nicely chilled water for the way back :-).
Professional barbecue equipment :).
Food.
More food.
Cervelas on the fire.
And Hamburgers on the grill.
Goooooood!
Back at the fun :-).
Good teamwork.
Beautoful views all over.
.. and everything prepared to survive.
On the way back.
More views.
Don’t fall :-).
Find Tobias and Timo.
Making contact with the locals.
Ohoh …
Is the cow laughing?
Ok, it’s not hostile.
Nature.
Getting late … but still ok.
The target!
And done … it was a rather nice trip. We may do it again :-). Thanks all for making it so much fun!
Jan62013
My Mexican friend Edgar told me about a Mexican tradition: to eat “Rosca de Reyes” (Kings Cake) on the 6th. Since I really enjoy Mexican food and traditions, we just made one! Here’s how it went:
The dough 🙂
The “rosca”?
After the “going” (it grew quite a bit (too much?)).
And the final product! It tasted awesome!
Happy king’s day :-).
Dec112012
Three of the 53 2012 ACM fellows have a strong HPC background!
Congratulations to Keshav Pengali, Robert Schreiber, and Kathy Yelick!
A good sign for the small but growing field!
Sep212012
Actually, everything said … see my earlier posts for the features included (and not included). I also gave a keynote at the Multicore Challenge Conference last Tuesday talking about the Challenges that MPI-3.0 reacted to (talk slides).
The complete official standard can be found at http://www.mpi-forum.org/docs/docs.html .
Kudos MPI Forum!
Aug32012
Finally, after the last meeting in Chicago a couple of weeks ago and some more minor edits, we (the MPI Forum) were able to release our first public draft of MPI-3.0. Jeff has an explanation why it took a while :-).
This draft includes everything that has been voted into MPI-3.0. The standard is closed for major changes, so all features are in place. We put out this draft to the public to allow for comments until we vote on finally (on each chapter) in the September meeting. We plan to ratify the standard at that meeting if there are no other delays (one never knows!).
Nevertheless, we remain open for changes (especially bugs) and feature requests (which will go into future versions, e.g., MPI-3.1). Minor changes, that can still influence MPI-3.0 include any kind of bug in the released document (minor or major) or small explanations and additions that don’t change semantics significantly. However, we’re trying to keep the changes to the document minimal, so only absolutely necessary changes will be considered.
The draft is available at http://meetings.mpi-forum.org/draft_standard/mpi3.0_draft_2.pdf.
If you find issues, either contact the Forum member of your choice or broadcast to a larger group via the mailinglist (http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-comments, you need to be subscribed). We accept comments until September 6th and we thank you for your support!
Happy reviewing and exploring of all the new features! PS: my earlier posts on the new MPI-3.0 features remain completely valid and provide a good overview of the news in MPI-3.0. If you are interested to learn more about MPI-3, you may also consider to look through some of the tutorial materials that I and Martin provided! We are planning to offer this tutorial at future conferences, so watch out!