As far as I can see from the paper, it's offering a technique for getting 3N capacity out of five capacity-N discs, with protection against one disc failure in conjunction with two badly-located unreadable sectors.

(whereas RAID6 gives you protection against two whole-disc failures, but if you lose one disc and have unreadable sectors in the same place on two of the others then you've lost that sector)

It seems to involve fifteen reads and five writes per sector write, because it works by looking at groups of sectors on each disc, whilst RAID6 requires three reads (the sector you're overwriting and the two parity sectors) and three writes, so there's a lot more bandwidth used.

Basically this is a paper which has discovered a pretty mathematical pattern, with a dubious justification that it might be relevant for data recovery. It doesn't make sense in a world in which discs tend to fail mechanically rather than to develop individual bad sectors.

"many clusters where latency or cost is more important than bandwidth are still being built with Gigabit Ethernet switches"

Gigabit Ethernet latency is *dreadful*, 180us or more for a ping between two boxes attached to the same switch! You use a gigabit interconnect only when latency is immaterial and bandwidth not terribly important; thankfully a lot of interesting jobs have that property.

Unfortunately the slower grades of infiniband, which were still cheaper and lower-power than 10GbaseT when they started to be phased out, are no longer readily available new.

Actually a class of one

The Soyuz down-mass is 100kg only, the Dragon test flight brought back 660kg, Dragon is specified for three tonnes. The Space Shuttle down-mass was something like twenty tonnes and it would routinely return with about five tons of stuff packed inside a four-ton MPLM.

... also more efficient than our competitor's model with integrated toaster

You always ought to give your competitor the benefit of the doubt in this sort of comparison, otherwise people will question your honesty - having said that the machines are usually compute-limited, why are they comparing to an essentially-HPC setup full of dual-socket eight-core Xeons rather than low-power Ivy Bridge E3-1200 systems?

This is a function-field-sieve discrete logarithm over GF(3^582); it's asymptotically equivalent difficulty to special number field sieve factorisations, which casual groups have managed to do for 1061-bit (320 digit) numbers. As the Fujitsu paper http://www.nict.go.jp/en/press/2012/06/PDF-att/20120618en.pdf points out, it involved a fair amount of implementation work but no more computing than finding a single DES key.

You've got cores and core-groups confused at the start; you write

The Fermi GPU had 512 cores, with 64KB of L1 cache per core and a 768KB L2 cache shared across a group of 32 cores known as a streaming multiprocessor, or SM

where in fact there is a single 768KB L2 cache shared between all 512 cores, and 64KB L1-like memory shared across each SM.

'The Fermi GPU has sixteen streaming multiprocessors, each comprising 32 cores and 64KB of fast memory, and a 768KB L2 cache shared by the sixteen SMs' would be a more correct way to put it.

Intel thoroughly missing the point here

These are not credible competitors to four-socket Opteron boxes, because they're so enormously more expensive; even if you regard a Sandy Bridge hyperthread as equivalent to an Opteron core, $1611 for eight 2.2GHz SB cores versus $639 for sixteen 2.2GHz cores is a big premium.

The four-socket Opteron boxes are great for HPC-like jobs, my 4x6168 machine delivers 360GFLOP peak for about 700 watts and I've not had to fiddle around with Infiniband cards and switches to connect smaller boxes together.

Last para is rather unclear.

Blue Gene/Q is the energy-efficient one, Hector is the XE6 (enormous pile of Bulldozers).

Blue Gene/Q is in no sense a distributed computing project; it's a collection of cabinets (probably four cabinets) each containing an enormous pile of custom IBM chips each containing 16 PowerPC cores.

Two too many millions in the first sentence!

Roughly what they've done

This is a weak-lensing survey. The idea is that the shapes of galaxies seen from Earth are changed by gravitational lensing from mass concentrations that the light has passed through on the way; so you produce an enormous sample of galaxies which you're reasonably confident are at about the same, large distance (by looking at their colours in several infra-red bands: 'photometric Z' is the term, Z being the symbol for red-shift), and the map plots roughly the extent to which the galaxy images in each patch of space are elongated.

The galaxies are small and the variations in their shapes are comparable to all sorts of other systematic effects caused by (for example) the presence of the atmosphere, so there are several statistical steps in there, which is why the maps look so blobby; the confirmation is at least in part that the brightest blobs turn out actually to contain foreground galaxy clusters, though a bright blob without a galaxy cluster would be a much more exciting result.

I suspect it's more hope for Jupiter

They haven't got radial velocity data to get the masses, and the paper is in Nature and not open-access, but the more technical summaries suggest that the deep-fried planets are the iron cores of former gas giants.

Three years isn't that long ago.

The average three-year-old server was bought in mid-2008, so will have dual Harpertown quad-core Xeons, not 'single or dual cores'.

Lanthanide halides don't behave like UF6

The Kroll process sounds reasonable at first sight, but most of the lanthanides really only go to oxidation state +3 (the ones that don't you can separate out much more easily by taking advantage of that), so I don't see how you get enough fluorines around them to get nice volatile compounds like the transition metal highest-valency fluorides. The lanthanide trifluorides seem to be nice solid things, melting around 1500C (without much range in the melting points, so the distillation's not going to be completely straightforward) and used in glasses for infra-red lenses and optic fibres.

The bromides are a bit more volatile, and probably the iodides even better, but I'd be very worried about thermal decomposition.

You could go to organolanthanides or borohydrides, but coating the reactor with LaB6 seems like the beginning of quite an expensive day, and I'd be impressed if Gd(tBu)3 could be distilled without decomposing.

Grades of plastic?

Apple cables are noticeably thinner and bendier than many other manufacturers'; this lets the cables lie more tidily on the desk, and makes them easier to thread through small spaces, but I imagine it also lets a given force bend them in tighter radii than other manufacturers' cables, so allowing more damage to the innards. So I wouldn't be terribly surprised by this story; it's a side-effect of designing for prettiness.

Image stabilisation FTW

Alex said "I have a 300mm (450mm equivalent) zoom on my APS-C SLR camera and have a job getting steady shots with that. You have to have a tripod."

Thankfully, Nikon are now quite good at vibration-reduction - it's the really big advance in lens technology in the last decade, you no longer need to hold the camera still. One of the pictures in the article is taken hand-held at 624mm equivalent and looks pretty sharp; even the pocket Canon camera I have can take sharp macro shots of coins in poorly-lit museums with a quarter-second exposure.

Languages designed after the invention of threading thread better. WWHT?

One of Google's big observations is that Java programming style tends to be very threaded, so idiomatically-written Java programs do tend to spread nicely over multiple cores once you have the multiple cores available. Writing explicit threading in C++ is three kinds of pain, so people are generally not willing to do that, but it's much less uncomfortable in the managed languages which have threads as a primitive.

I have a lot of software that isn't terribly communicative nor terribly memory-intensive, and the advent of quad-cores is wonderful for this; I can run a dozen copies of the software while having only three loud fan-heaters on my flimsy desk. If two six-cores cost less than three four-cores, one motherboard and a case, I'll buy them; if not, not.

what's a factor 1000 between friends?

for 'gigaflop' read 'megaflop' throughout

40Gflops about as exciting as lukewarm marmalade

Whilst 'a single Sparc64-VII chip can deliver 40 gigaflops of number-crunching power with all four cores running at 2.5 GHz', so can a single Phenom 9850 of the kind that Dabs will sell you for less than a hundred and fifty of your Earth pounds

c+p fundamentally incompatible with the iphone interface

Cut-and-paste is more than just a software issue - it would complicate the interface hugely. You suddenly have a concept of a selected region, and need a selection mechanism, and I can't think of a sensible selection mechanism using the touch-screen; given the absence of c+p, I assume that neither could Steve Jobs and his merry men.

I've only found the lack of c+p irritating in combination with the trivial problem that touching a phone number only lets you call it, rather than texting it or adding it to a contacts list; that one I would expect to see fixed in a patch release.

What's wrong with sleaze and guile?

Umm, if it's making up a different private key each time then the fifteen million years of compute work are required once per infected machine, which is clearly absurd; and if not, then all Kaspersky has to do is pay the ransom once then disassemble the code they receive and publish the private key that it contains.

Breaking a 1024-bit RSA key is not impractical because you need fifteen million years of sieving, it's impractical because there's a stage at the end of the operation which requires a computer with some tens of terabytes of uniformly-accessible memory.