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Apple Wins VT in Cost. vs. Performance
danigiri writes "Detailed notes about a presentation at Virginia Tech are posted by by an attending student. copied most of the slides of the facts presentation and wrote down their comments. He wrote some insightful notes and info snippets, like the fact that Apple gave the cheapest deal of machines with chassis, beating Dell, IBM, HP. They are definitely going to use some in-house fault-tolerance software to prevent the odd memory-bit error on such a bunch of non-error-tolerant RAM and any other hard or soft glitches. The G5 cluster will be accepting first apps around-November."
mfago adds, "Apple beat Dell, IBM and others based on Cost vs. Performance alone, and it will run Mac OS X because 'there is not enough support for Linux.'"
3 MW power, double redundant with backups - UPS and diesel
1.5 MW reserved for the TCF
2+ million BTUs of cooling capacity using Liebert's extreme density cooling (rack mounted cooling via liquid refrigerant)
traditional methods [fans] would have produced windspeeds of 60+ MPH
Does it render?
Yes, incidentally, it does. The units came with high end graphics cards
Aside from games, when is a high end graphics card needed for rendering and not just displaying a rendering.
# 3 MW power, double redundant with backups - UPS and diesel * 1.5 MW reserved for the TCF
# 2+ million BTUs of cooling capacity using Liebert's extreme density cooling (rack mounted cooling via liquid refrigerant) * traditional methods [fans] would have produced windspeeds of 60+ MPH
Seems that they did talk about both.
Okay before we get going with the same discussion about ECC vs. Non ECC, and all the flames start from people perusing slashdot who think they are more in the know than the PhD's at VT who have been working on this for months I want to point a few things out.
1. The majority if not all of the bit errors that ECC corrects are caused by thermal noise. Thermal noise is an issue in a cluster of rack mounted 1U units due to the difficulty of cooling such tightly spaced units generating so much heat in so small a space. It is not an issue in a cluster of DESKTOP machines utilizing a Liebert system with way more cooling capacity than is needed.
2. Even if somehow a none-thermal bit error occurs, each node has 4GB RAM. The probability of it being in an OS or application critical (especially given the converging nature of many long running calculations) piece of RAM as opposed to an empty piece of RAM is small.
How many of you are reading this from a desktop without ECC RAM that has an obnoxiously huge uptime? ECC is a non-issue in a well-cooled cluster of desktop cased machines.
And keep in mind that the RAM on each machine is 4 GB.
Maybe they meant that Linux doesn't run on the G5 at all yet, and the only company that seems to be interested in Linux on the G5 (Terra Soft) is a pretty small player.
http://nowlab.cis.ohio-state.edu/projects/mpi-iba/
The viriginia folks must have one huge room with some massive air handlers to circulate the air that will be trapped behind the towering walls of 1000 4U boxes.
I don't know any more than what's publicly availble, but the VT follks in the know have said that they've designed a specialized, liquid based cooling system precisely because of the issues wrt cooling this many units. The FA makes reference to this many units generating windspeeds of 60mph from fans alone.
I am gonna guess that behind each G5 rack will be a radiator type arrangement, with cooled pipes flowing with a liquid that will carry the heat away from the internal airspace, much like a large car radiator. I don't know if that would be cost-effective, or what it would take to move that much liquid, or if the radiator could be made to transfer enough heat fast enough. Maybe the liquid cooling units actually replace the internal fans directly. Who knows--I think we'll get some more details on this this week as the G5s start to come out of their boxes. They've apparently received about 10% of them already.
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$tar -xvf
What did you think last weeks announcement was???
Mod point free since 2001
Read on. They're putting 8GB of RAM in each machine.