Posts by mr.mac52

1) Message boards : Technical News : Colo! (Mar 28 2013) (Message 1351953)
Posted 54 days ago by

I am always amazed about how much you do with so little gear. Best wishes and hope you don't have to pull any all nighters getting it up and running on the flip side.

John

2) Message boards : News : Server Relocation (Message 1348901)
Posted 63 days ago by

mr.mac52

Great news! I hope all goes well with the planning and execution.

3) Message boards : Number crunching : Remote Desktop disables GPU's (Message 1339004)
Posted 95 days ago by

mr.mac52

I've used TeamViewer for several years with good results.

4) Message boards : Number crunching : How many Computers do you have Running BOINC Projects? (Message 1337468)
Posted 99 days ago by

mr.mac52

I have two rigs, both are Quad Core 2 and each have one GTX 670 running 3 tasks.

5) Message boards : Number crunching : 2012 - 2013 Marathon Pledge Drive (Message 1270944)
Posted 283 days ago by

mr.mac52

Dear John McClelland,

Thank you for your gift to:

SETI@home

We received your gift of $100.00 via Mastercard on 08/12/2012. Your confirmation number is 96798.

6) Message boards : Number crunching : CLOSED- SETI/BOINC Milestones [ v2.0 ] - XXII -CLOSED (Message 1080960)
Posted 818 days ago by

mr.mac52

Congrats to all in this thread...

This week I dropped into the three digit ranks after many years of crunching; almost 8 years of work with 8.2 million credits for SETI@home.

-j

7) Message boards : Number crunching : Optimized CUDA Issues & '-12 Unknown error' (Message 923349)
Posted 1388 days ago by

mr.mac52

Thanks Fred!

8) Message boards : Number crunching : Optimized CUDA Issues & '-12 Unknown error' (Message 923347)
Posted 1388 days ago by

mr.mac52

http://setiathome.berkeley.edu/workunit.php?wuid=487147003

WU true angle range is : 0.381546
After app init: total GPU memory 671088640 free GPU memory 538587136
Exception detected inside cudaAcc_find_triplets, dumping client state
icfft=196155, PoT_activity=0, PoT_freq_bin=-1SETI@home error -12 Unknown error
cudaAcc_find_triplets erroneously found a triplet twice in find_triplets_kernel
File: ..\analyzePoT.cpp
Line: 348

9) Message boards : Technical News : More of the Same (Jul 09 2009) (Message 916581)
Posted 1412 days ago by

mr.mac52

Sorry for the length of this post.

From: Gary Charpentierâ€™s note 916371

Answered a long time ago.
Tweenday Two (Dec 27 2007)

In reality, we have a 1GBit connection to the world via Hurricane Electric, but alas this is constrained by a 100 Mbit fiber coming out of the lab down to campus - it will take some big $$$ to upgrade that, which may happen sooner or later (as it would not only benefit us).

I mentioned how we seem to have a 60Mbit ceiling...

... We have gigabit all over our server closet (more or less - some older servers are 100Mbit going into the 1Gbit switch).

From: seti@elrcastor.comâ€™s note 916409

one problem is it could be multimode fiber with a length, short enough for a 100mb connection to work, less than 2km. But to do gig over multimode with a WS-G5486 LX/LH gbic you are limited to 550m. To get gig to go 2km or more you need single mode fiber, when you use single mode fiber with a LX/LH gbic you get 10km.

From: Ned Luddâ€™s note 916550

I know I pointed to 6a) but many of the solutions proposed (P2P, Torrent, offsite upload/download servers) feel like taking a problem and moving it around.

The problem is the 100 megabit pipe, and the servers themselves.

It looks to me like the current infrastructure can handle the current average load. The problem is how the load builds during an outage, and how networking works when the load is near or above 100%.

Increasing the bandwidth (and more/better servers) raise the 100% mark, and are always going to be a good idea.

I just wonder if there are some others that could help, without reshuffling the problem.

----
Ok, I accept the challenge of looking at the 100 mb pipe.

The use of laser based GBICs will not extend the range of multimode fiber beyond the 2 km limit and most limit it to 500m or less. To do this you need products that use other technologies to exceed the distance limitations.

There is basic information needed on the existing fiber link in use today to realistically speculate on potential solutions.

#1 is understanding the campus infrastructure. There have been many campus level fiber networks that used a higher level switch to drive individual drops to points of presence (POP) in each building. If that is the case here, the possibility of facilities agreeing to allow the use of this specific fiber optic pair to be used as â€˜dark fiberâ€™ would be critical. If it is dark fiber, you are usually not limited by the owner of the fiber as to what equipment uses it.

#2 is the type of fiber in use. The common multimode fiber in use today is either 50/125(OM2) or 62.5/125(OM1), there was a 100/140 variant but Iâ€™ve never seen it in the field. Knowing this can give us some idea of optical losses to be expected.

#3 is the length of the physical fiber in use today. The distance is only one of the limiting factors but it is important. When facilities install fiber infrastructure it is generally not a shortest path run. If the real length is known fine, if not an OTDR can estimate the length as well as the over all attenuation of the cable. It is also useful to know if any patch panels are in use as this introduces more light loss and possible problems.

#4 is the light loss in this specific fiber run. There are two ways this can be specified, round trip light loss assuming equal loss for the pair or individual fibers so that we really know the quality of each strand. Most optical testers will test at more than one wave length which is useful if looking at current technologies to solve the speed problem.

Once these questions are answered we can proceed to consider the options that might work in this specific environment. What options can we speculate on without this info; I was hoping you would ask.

#1 if the length is 2km or less and we know the light loss figures, the laser GIBC solution could work given the equipment using the GBICs can work at higher link speeds and distances.

#2 if #1 is not valid we could consider using wave division multiplexing (WDM) to use separate wave lengths in parallel to get to higher speeds.

Two products that Iâ€™ve seen in use with multimode fiber are the PL-400 and PL-1000 by PacketLight Networks. The PL-400 can handle GbE and the PL-1000 10GbE and depending on the physical fiber, multiples of these interfaces. They have options for either Course WDM (CWDM) or Dense WDM (DWDM), the CWDM is usually significantly less expensive. Speaking of costs, they are not inexpensive but I think much less costly than installing new fiber infrastructure as they are built for this very purpose.

If on the other hand, facilities will not allow the use of their physical fiber as dark fiber, you are at their mercy on costs to get higher speeds to your building.

FWIW and YMMV

John

10) Message boards : Number crunching : Reliable backup project (Message 911667)
Posted 1426 days ago by

mr.mac52

The set I work on for times such as this:
Cosmology
Einstein
Milkyway
Rosetta

I can't tell you when the last time I ran out of work with this set of applications.

I do set the shares to favor SETI above all else so that when SETI is down, I still keep all four cores running flat out.

YMMV

John

11) Message boards : Number crunching : Does AP get priority for download?? (Message 886625)
Posted 1493 days ago by

mr.mac52

For what its worth, my mix of MB 6.08 to AP 5.03 is about 10 to 1 with Raistmer's optimized apps. This is from monitoring it for about the past week or so.