* Posts by Tom Womack

131 posts • joined 7 Jun 2008


OpenBSD disables Intel’s hyper-threading over CPU data leak fears

Tom Womack

Re: A Kludge

The whole point of hyper threading is that it works well on code which *hasn't* been thoroughly optimised. If you've got two vector instructions lined up for each tick, hyper threading can't get you anything; if your thread is waiting two hundred ticks for the L3 cache to divulge the next operand, having another thread running until it too needs to wait for the L3 cache is extremely helpful.

I am very sad at the way that people are using fairly hypothetical security arguments to disable the features that make processors actually good at computing: I am willing to do my banking on my phone if that means my actual computers can crunch numbers at a higher percentage of its peak speed.

Tech rookie put decimal point in wrong place, cost insurer zillions

Tom Womack

Re: Lira?

I was, accidentally, there for the changeover; all the banks and ATMs were closed for a couple of days, which was somewhat irritating since I'd turned up without any cash because Romanian lei are hard to come by.

Particularly irritating was that, when the ATMs reopened, they were still dispensing the old notes!

Close Encounters of the Kuiper Belt kind: New Horizons to come within just 3,500km of MU69

Tom Womack

Re: It is a long way away from the sun

It's about 45AU from the Sun, so sunlight is two thousand times fainter than on Earth - but that's still about a hundred times brighter than full-moonlight, and with a camera on a good tripod you can take pretty good photos in full moonlight.

Canonical sharpens post-Unity axe for 80-plus Ubuntu spinners

Tom Womack

Re: Reboot

What do you mean 'requiring'? It suggests you might want to reboot, but my Ubuntu nodes have mostly been up for two or three months.

Apple eats itself as iPhone fatigue spreads

Tom Womack

Re: Headphone socket

Apple seem to have had real difficulty manufacturing the 7+, so if you wanted to walk out of the shop with a large Apple phone you got a 6S+; and it seems that most people who want an expensive new phone want a large one.

Fitbit throws fit, emits writ for outfit's non-hit, rather sh*t, 'Fitbit' kit

Tom Womack

Re: That's hilarious

Complain publicly to @fitbit on Twitter, with photos, and they'll likely send you a new one for free.

I'm on my third.

Violin Memory shares collapse as it files for chapter 11

Tom Womack

Re: What went wrong?

The USA does this to an extent - if you hold the shares for less than a year, you pay income tax on the profits, whilst if you hold them for longer you pay a lower capital-gains-tax rate.

Custom silicon, 9PB storage boxes, and 25Gb Ethernet – just another day in AWS hardware

Tom Womack

Re: twinax cable

No, actually Cat8, twisted pair rather than twinax (40GBASE-T). Not sure what black magic they're using in the transceivers. The cable needs to be shielded and tested up to 2GHz, but it is a twisted-pair cable.

Tom Womack

25Gbit can be run over a single fibre wavelength or (amazingly) over within-rack lengths of Cat8 copper; 40Gbit either uses four 10Gbit fibres or (more expensive) four wavelengths on a single fibre.

ESA lofts one astronaut and four Galileo satellites into orbit

Tom Womack

Putting on my pedant hat, ESA had been launching the Galileo satellites on Soyuz rockets owned by Arianespace and launched from their site in French Guyana; so Roscosmos got the money for the launch vehicle to pass through to the manufacturer, but was not responsible for the launch.

(the two earliest Giove satellites did go up from Baikonur)

It's not completely obvious that launching 675kg satellites four at a time on Ariane 5 (which can happily take six tons to the harder-to-reach geosynchronous orbit) is better than launching two at a time on a smaller rocket.

'Pavement power' - The bad idea that never seems to die

Tom Womack

A competing manufacturer of annoying squishy expensive pavements says '5W continuous', so I think that particular problem is just a matter of a badly-written press release.

The problem is that a 5W generator produces £5.70 of electricity a year at retail price, and it seems wildly unlikely that the maintenance of the annoying squishy pavement, let alone the interest on a loan to cover the install price, is of that order of magnitude.

Australia teases binning x86 for Power CPUs in new supercomputer

Tom Womack

If they're trying to fit a petaflop in five racks for $3 million, the processors will just be sitting there driving the GPUs. My guess is that they're anticipating nVidia, who has quite tight links with POWER, producing a POWER-and-GPU box which might be more cost-effective than the current Xeon-and-GPU box.

($3 million is interesting close to what you get if you divide a petaflop by the current $129k 42.4TF nVidia DGX100 and expect a small discount for buying in bulk)

In its current state, Ubiquiti's EdgeSwitch won't have much of an edge on anyone

Tom Womack

Re: The problem with es-16-xg is not just the SFP+ cables

This is a comment guaranteed to not fill you with delight, but: have you tried the cable in more than one port on your switch? I have some cables that work only in ports 6 and 8 (and, accordingly, a bag of fibre transceivers winging its way to me from fs.com)

If any idiot can do it, we're heading in the right direction

Tom Womack

Re: DACs

And switch vendors seem to think that 'doesn't work with some brands of DAC in some ports' is a problem they address by maintaining a compatibility list, or in the worse cases by mandating you use cables provided by them and made out of mark-up coated in a thick layer of dielectric expense, rather than by fixing their rassenfrassen switch hardware.

Mine's the one with the distress-purchase fibre transceivers in the pocket

Tom Womack

Re: hate DACs

Sadly the cheap server motherboards have integrated 10G with SFP+ connectors, and SFP+ to 10GBaseT transceivers don't exist because driving 10GBaseT requires more power than SFP+ is specced to provide.

If you're buying the network card, 10GBaseT is not a bad choice (if you're going to have the exotic cabling faff, at least go for 40Gbit Infiniband and have the extra speed); if it's integrated then you're screwed.

Linus Torvalds says ARM just doesn't look like beating Intel

Tom Womack

Re: ARM is not very popular as desktop

Since Conroe I have expected PCs to last forever. Builds have grown big enough that it's nice on a software-development workstation to have 2GB per thread and ideal to have 4GB per thread, but that's been possible since Haswell.

A problem is that memory controller IP, which is very black magic and comes from a very small number of suppliers, charges a big premium for each extra address line; so it would be a significant extra expense to make a phone or set-top-box SoC which happens to be able to support 16GB, and therefore you're not going to be able to make a nice 16GB devboard around a ubiquitous SoC.

EU ends anonymity and rules open Wi-Fi hotspots need passwords

Tom Womack

Re: Let's step back for a second

So you have to stop offering really crappy free WiFi. Where's the issue? If your free WiFi is not making your coffee shop a fiver a day in custom, why are you bothering? When almost everyone in the coffee shop will be accessing your wifi using a mobile device which can happily switch to 3G, providing a service worse than 3G is a waste of time.

Map to the stars: Gaia's first data dump a piece of 3D Milky Way puzzle

Tom Womack

Re: It's already all wrong....

And Gaia watches them move and measures how far they've moved, so two million of the stars are annotated with velocities already and about a hundred million will be by the end of the mission.

The researchers did do the obvious experiment to see whether any velocities were changing over time, because that would be an exciting result, but didn't find any convincing examples - it turned out simply to be an excellent way to find one category of mistakes matching up stars in the fifteen-year-old Tycho catalogue.

Tom Womack

Re: Pleiades

Hipparcos data analysis is a really hairy problem - van Leeuwen spent a decade inventing new data-reduction techniques and re-running the whole analysis, the fact that the satellite was stuck in geostationary transfer orbit because its apogee motor failed to fire didn't help.

Gaia's estimate for the position of the Pleiades is in one of the free-access papers published today, and is unsurprisingly absolutely bang in the middle of the results from Earth-bound telescopes or from astrophysical arguments.

Tom Womack

The error in this data release is 0.0002 arc-seconds and the intended error at the end of mission is 0.000007 arc-seconds. Star positions to an accuracy of 7 arc-seconds can be achieved with a DSLR and a reasonable telephoto lens, no need for a two-billion-Euro mission at the L2 Lagrange point.

'Oi! El Reg! Stop pretending Microsoft has a BSOD monopoly!'

Tom Womack

Re: Machine Operating System

I think that's a Master, configured to use DFS rather than ADFS at boot

World eats its 10 millionth Raspberry Pi

Tom Womack

Re: About 20 pounds too much.

Or think of it as a collection of bits all arriving at the same time and selected so that you didn't have to go and order another PSU and wait two further days for it to turn up, plus a £15 donation to the Raspberry Pi foundation.

Ancient radioactive tree rings could rip up the history books

Tom Womack

I'm afraid you've screwed up the BCE->CE correction

It seems you have changed 'BCE' to 'CE' throughout. The Assyrian eclipse was in 763 BCE, we are reasonably confident that the foundation of Rome was 753 BCE, the first year of the Gonghe Regency, after which Chinese chronology is apparently pretty well-known, is 841BCE.


This means the last three paragraphs of the article, which I suspect are commentary inserted by the article author rather than extracted from the source publication, don't make much sense.

Tom Womack

You're 1500 years out!

The Miyake event was in 775 CE (during the reign of Offa, king of Mercia, and at the end of the reign of Constantine V, Emperor of Byzantium), not 775BCE (around the time of the first Olympic Games in classical Greece, and well before the invention of either Mercia or Byzantium). The other one is 993-994CE (reign of Ethelred the Unready)


They kept that quiet: Toshiba unsheathes FlashBlade rival

Tom Womack

Trivial complaint, but '8 x 512GB DDR3L DRAM' clearly ought to read '8 x 512MB DDR3L DRAM' - really very implausible to have more DRAM than Flash in this appliance!

Seagate flashes 60TB (yes, sixty) SSD monster

Tom Womack

There seems to be some Enterprisey over-engineering going on here; I rather like the idea of a card with a PCIe switch and four or six M.2 NVMe slots on it, so I can run software RAID0 across six cheap Samsung half-terabyte NVMe cards. IDT make a switch chip that would be perfect for this, which costs about $200, so I'd expect a competent Guangzhou shanzhai to make a profit selling the card for £250.

A journey down the UK's '3D Tongue' into its mini industrial revolution

Tom Womack

Renishaw is not privately-owned: FTSE listed (ticker RSW), a member of the FTSE250, no sign of an unusually major shareholding by directors. Not a bad company, one of the super-exporters whose stock has soared since Brexit

Singapore Airlines 777 catches fire after engine alarm

Tom Womack

Re: "five have been lost"

One's MH370, to which your comment regrettably applies, and the last one is Asiana Airlines 214, which was landed so incompetently at San Francisco that three people died and the plane was destroyed by fire.

I hadn't realised that BA38 (the short-landing at Heathrow caused by ice in the heat-exchanger) had written off the aircraft.

Parliament is building a new website – and it doesn't want GDS anywhere near it

Tom Womack

Re: MP's should educate themselves about the web first!

That's exactly what they did; they looked at theyworkforyou.com and then asked the people who designed that to tell them what they needed to do for the Parliament Web site. Seems a pretty decent approach to me.

NVMe over Ethernet is the future. And that's how we roll – Tegile

Tom Womack

Re: Question too

Ethernet can be over copper or over fibre; it's just a way of wrapping up frames.

"NVMe over Ethernet" I suspect just means that there are 16 bits reserved for queue-number and 16 for position-in-queue in whatever secondary wrapping they're using

Digital ad biz is fraudulent by design, complain big brands

Tom Womack

Re: what's in a word

That's hardly recent, and it may well be an aspect of culture clash - it's an important plot point, breaking down the relationship between backwoods American boy and outback Australian girl, in _Beyond the Black Stump_ in 1956.

Science Museum maths gallery to offer the perfect pint

Tom Womack

The first transatlantic flight was in a Curtiss seaplane, and stopped at the Azores

Brexit? Cutting the old-school ties would do more for Brit tech world

Tom Womack

Re: I don't much care...

We're not building enough houses. The reason for this is the ridiculous post-war imposition of the Green Belt. Abolish planning permission for a couple of decades and we will replace the housing problem with some easier problems to do with public-transport provision and building primary schools.

Tom Womack

Why would you bother looking for work in Poland? This is the era of capital; take the money from selling a two-bedroom house in Zone 2, buy an apartment block in Krakow with half of it, stick the other half in UK-based investment funds, and you get to live the rentier dream. Settle down with a nice Polish girl somewhere where you can actually live off the interest.

HP Inc-eption: Our new 3D printers print themselves, says CEO

Tom Womack

Re: "Fifty per cent of the bill of materials of our 3D printers are printed by our 3D printers"

And that's the case for an awful lot of situations. There are an enormous number of objects for which the total size of the market is smaller than the minimum lot size for the most efficient manufacturing processes.

Being able to move away from using standard parts which aren't quite the right size but are produced efficiently in huge volume by some commoditised supplier, to using parts which are exactly what you need and are produced efficiently-enough in the volume you need is super.

India launches hypersonic space shuttle precursor

Tom Womack

Because there are still an awful lot of poor people in India, and paying people directly to minister to them works better than trying to convince the Indian government to change its fund-allocation priority.

Amazon's AWS cash machine embiggens, breezes past $2bn-a-quarter mark

Tom Womack

Re: Profits

I'm guessing around $2.5 billion, since the article indicates that they reported $0.6G on the $2.6G quarter.

Trouble at t'spinning rust mill: Disk drive production is about to head south

Tom Womack

Re: The analysis that SSD may save them is probably wrong.

But when it comes to 'price for the smallest thing big enough to do the job', SSD is already winning; the smallest SSD you can get is big enough, and is cheaper than the smallest HDD you can get.

There were a couple of years when I had compute nodes with the OS on 8GB USB2 sticks; I don't recommend this, they do wear out and reinstalling the OS even on a compute node is never as painless as you hope (CUDA drivers :().

Tom Womack

Re: That's now

I think the author of this story hit the lede: that analysts who presumably know what they're doing have reckoned that there won't be an explosion in data-storage demand from the cloud companies, that they'll keep buying discs at the rate they have been rather than continuing to grow demand at 20% a year.

"Big Data Won't Be That Big" seems a perfectly registerian headline ...

Tom Womack

Re: I'm puzzled

People don't record much video, because taking photos that look sort of about the same category of as good as professional photos isn't terribly hard, but doing that with video is really quite challenging.

The restriction on numbers of photos taken, even with good DSLRs, stopped being SD-card capacity a couple of years back - I'm a pretty enthusiastic photographer, took three 32G SD cards on a three-week trip to South-East Asia and only used half of one. People realize that they don't bother checking through the nineteen shots of a badly-posed monkey that they took by holding the button down, and move to pressing the button once.

Apple pulled 2,204lbs of gold out of old tech gear

Tom Womack

Re: Love 'em or hate 'em...

If you sell aspirational stuff that lasts, then your customers are delighted that they can sell their iPhone 4S on for a hundred pounds when they buy a 6S+, and the person who gets an iPhone 4S and otherwise would have had some lowest-end Android monstrosity is also delighted. If you're lucky then the second-hand customer will get richer and start buying new.

OnePlus X: Dinky little Android smartie with one or two minuses

Tom Womack

"It's a far cry from the richer CyanogenMod that burnished the OnePlus One – but OnePlus has had to rebuild from scratch." confuses me: could the article author explain *why* OnePlus had to rebuild from scratch?

Toshiba rolls out PC-busting monster: 1 terabyte TLC flash SSD

Tom Womack

Re: Why SATA?

And at least one Cupertino-based vendor has; if you want gigabyte per second filesystem access, a Macbook Pro is the way to go.

Coding is more important than Shakespeare, says VC living in self-contained universe

Tom Womack

Re: Excellent article

His vision is highly-trained people. But there is a lot of time in the evenings in which you can read whatever you like, utterly independent of the training you have in how to drill teeth, remove spleens, diagnose common diseases of the kitten, weld two-inch-thick copper plate, cut three pieces of wood so that they fit together into a beautiful corner, write C++, read Danish, design an injection-mould ejector which actually ejects the pieces, locate a sewer pipe two metres underground, convince a CIO that your product meets their needs, or whatever makes you money.

Tom Womack

Re: My own creativity is expressed not through writing plays

That's the point of reading books. Which you can do happily whatever else you do with your life, and which you will find yourself with a great deal more comfort to do if you have a well-paid career in computing.

Doing a liberal arts degree is expressing a very unusual opinion as to the best way to spend the price of a decent BMW; the difference between reading the books in order to write two essays a week on them, and reading the books because it's the evening and that's what you do in the evening, is not worth that much.

That's cute, Germany – China shows the world how fusion is done

Tom Womack

Re: $14 Billion buys you and awful lot of oil

At the current unusually low prices, it buys you five hundred million barrels of oil, which is a little more than the amount China has so far burned in 2016.

UK govt right to outsource everything 15 years ago – civil service boss

Tom Womack

Do they think we're daft?

Yes, really high-end tech skills have a substantial market value.

But this means that, if you train people up in-house, they will notice that they now have a substantial market value and they will leave. Until someone developing a billion-item million-transaction-per-second system for HMRC gets paid the same as someone developing such a thing for Tesco, there will be a flow of people from HMRC to Tesco.

Terrible infections, bad practices, unclean kit – welcome to hospital IT

Tom Womack

Yes; you need to devote a modern computer to being a filter between the scanner and the world. Scanners are staggeringly expensive and modern computers very cheap, so this isn't a terrible problem, but IT organisations seem very resistant to models which treat the symptom when they think that merely by wasting vast amounts of development effort they can treat the cause.

Tom Womack

Re: This is does not compute

The powers-that-be appear to worry much more about the confidentiality of the data than about its availability.

Frankly I don't care if the consequence of any ambulance-operative in the country being able to discover instantly that I have blood type B is that every hacker in the world also knows my blood type.

Folk shun UK.gov's 'expensive' subsidised satellite broadband

Tom Womack

Re: Cross-subsidy

And that's why I'm proposing putting the USO on Openreach. They're big enough to absorb the cost of the USO and efficient enough that they can keep charging the same price as Virgin while doing so; and having satellite broadband available as an option to satisfy the USO means the last 0.1% cost Openreach no more than the £1800 per year each to settle their satcom bill (obviously in reality less, since Openreach will have a bulk arrangement with the satcom provider - sadly I suspect the economics doesn't work out for Openreach buying and operating its own satellite)



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