* Posts by Tom Womack

154 publicly visible posts • joined 7 Jun 2008


Creating a single AI-generated image needs as much power as charging your smartphone

Tom Womack

Running DiffusionBee on my M1 Mac mini while looking at PowerMetric in another window, I'm getting about 9.5 watts of CPU+GPU power usage for about thirty seconds per image generated, so 0.00008 kilowatt-hours.

Developing AI models or giant GPU clusters? Uncle Sam would like a word

Tom Womack

Re: GPT-4 is a thing

But the GPT-3 paper described the number of parameters and the compute intensity of the training, whilst the GPT-4 paper decided to be deliberately uselessly vague about that to free up pages to fill with useless analysis of 'AI risk' and of how they had crippled the model so that it didn't regurgitate bomb- or drug-making instructions which could be found in moments with an obvious Google search.

UK throws millions at scheme to heat homes with waste energy from datacenters

Tom Womack

Re: Intel

If the technology is more efficient, you can stick more of it in a box to use the same amount of power at the same temperature. There was a brief period where people used individual low-power servers, before realising that collecting jobs using virtual machines onto big machines hosting 256 vCPU in 2U and 1kW was a much more efficient use of the very-expensive space.

Tom Womack

Re: Assumptions

This has been a serious problem in Eastern Europe where district heating was provided by coal-fired power stations or by steelworks uneconomic in a global context. On the whole if people stop wanting to host computers in London we have some more serious problems, and replacing servers with electric resistance heaters is an ugly but effective solution. A one-kilowatt resistor costs about £50 compared to a £50,000 Sapphire-Rapids-plus-H100 server.

SAP user group calls for support deadline reprieve amid hospital billing worries

Tom Womack

Re: Two years to tender

Not really - what's bankrupted Birmingham is spending years underpaying their female employees and then having to find £700 million upfront to pay the second part of the settlement.

£100 million on an Oracle migration that was budgeted at £19 million and didn't work is a drop in the bucket compared to that.

Microsoft billing 3 cents a minute to revisit tedious Teams meetings via API

Tom Womack

This doesn't seem a plausible source of truly eye-watering sums; $1.80 per hour is $1400 even if a meeting contrives to be recorded 24/7 for a month.

Maybe there are people using Teams as a back-end for their surveillance cameras, and this should quickly make them stop.

SmartNICs haven't soared so VMware will allow retrofits in old servers

Tom Womack

Is CXL pricing really as keen as claimed here?

I needed a lot of memory in a server last year, so bought 12x16GB DDR4 sticks from bargainhardware for £42 each. The going rate is now £42 per stick for 32GB sticks, if I wanted 1536GB it would be a thousand pounds even if I threw away all the current DDR4.

It seems unlikely that a PCIe card with a controller significantly more complicated than the normal kind and 256GB of brand new memory chips can compete with that on pricing.

Is this a weird artificial market brought into existence by Dell's insane pricing on DDR5?

Academics have 'no confidence' in Edinburgh University's response to its Oracle disaster

Tom Womack

It's a pity that universities do not seem temperamentally suited to 'we had a vast and wide-ranging disaster with our Oracle implementation; we have managed to make it work reasonably well now; we will spin-off the better people in our internal IT group as a consultancy to help other universities have smaller and more confined disasters'.

Yes, UK universities are each a weird thing unto themselves, but they resemble one another rather more than any of them resembles the strongly hierarchically structured Wisconsin widget-works which SAP or Oracle ERP start off expecting to model.

A particular CAPSA problem seemed to be that 'a person capable of signing off expenses' and 'a thing against which expenses could be signed off' were both very heavyweight structures because there were expected to be about six of them in the company, whilst in a university every researcher got to be capable of signing off expenses against their own separate grant.

Arm still strong despite SoftBank loss as shipments pass a quarter of a trillion

Tom Womack

You don't have to. But releasing a marginal improvement annually still means that people replacing their 2018 smartphone with a 2024 smartphone get a nicer experience than the people who replaced their 2015 smartphone with a 2021 smartphone, and so on; as long as any chip company proceeds to the next ARM core, their competitors will be obliged either to do the same or to lower their prices. You can still get a brand new Samsung phone with eight A55 cores.

After long delays, Sapphire Rapids arrives, full of accelerators and superlatives

Tom Womack

The chips have been out with live hyperscale customers for a year, end-users willing to sign NDAs have had access to them in some of the clouds for three months, they have gone through twelve separate steppings, Intel has taken a half-billion-dollar charge on unshippable product (and is currently rearranging itself internally so that the processor group doesn't get to run new steppings through the fab at its own convenience); I think it is fair to call them battle-hardened now.

It's time to retire 'edge' from our IT vocabulary

Tom Womack

I'd always thought of 'edge' as 'can we run this chunky calculation on the nice fast ARM core that the user has already paid for in their smartphone, rather than on a no-better ARM core that AWS is charging us four cents an hour for' - if you're procuring new hardware for edge then you're doing it wrong.

Longstanding bug in Linux kernel floppy handling fixed

Tom Womack

I bought a new USB CD/DVD drive last Christmas, because I wanted to rip my Christmas CDs and my Mac Mini M1, whilst wonderful in almost all ways, lacks an optical drive. For as long as media is distributed on shiny discs, people will want to watch the shiny discs on computers ...

Japanese cubesat sends home pics from the far side of the Moon

Tom Womack

Re: Batteries not included

And Artemis was a particularly bad setup for cubesats, because they were installed in July 2021 and then there was no access to them, even for battery recharging, until the launch sixteen months later. 80% functionality rate for things stuck in a drawer for sixteen months is not bad ...

Minecraft's 'first luxury goods collection' features real-world $3,000 Burberry coat

Tom Womack

It's a perfectly normal high-quality overpriced beige coat from the front (https://us.burberry.com/monogram-motif-waterloo-trench-coat-p80647751) but with a really surprisingly ugly white creeper-face design in the small of the back.

I was thinking Burberry might be charging that much for a Burberry-check in-game skin, which would have been a bit more than averagely silly at the height of the NFT nonsense and absolutely ridiculous now.

Qualcomm: Arm threatens to end CPU licensing, charge device makers instead

Tom Womack

Re: For those unfamiliar with Qualcomm lawyers..

In particular, Qualcomm are accusing Arm of wanting to move to a per-device licensing model *like Qualcomm's*.

The 'no Arm extra IP blocks without an Arm CPU' part doesn't seem completely unreasonable, though I think Intel did do an x86-with-Mali SoC at one point - if Arm are willing to miss out on Mali revenue because they are worried about RISCV+Mali SoCs that's up to them, The claim that they might be moving to 'no non-Arm IP blocks on a chip with an Arm CPU' is obviously complete nonsense since Arm don't make memory or PCIe controllers.

HPE supercomputer to tell Singapore that it's hot, humid, probably going to rain

Tom Womack

That seems a tiny machine to be boasting about

0.4 petaflops, so a fifth the compute of the smallest machine in the June 2022 top500, and with 196 processors and no GPUs I would be startled if it took more than one rack (Frontier packs 128 processors and 512 GPUs per rack). I am surprised HPE bothered putting out a press release!

There are three larger supercomputers announced on the top500 in Singapore already.

Rambus offers chip designers a drop-in PCIe 6.0 subsystem

Tom Womack

In what form does this PCIe 6.0 Interface Subsystem come? Any PHY with fast SERDES is basically analogue design and very deeply process-specific at the moment, it would be nice to know what processes the blocks are available for.

(the press release at Rambus just says 'on advanced process nodes', it would be an interesting insight into the fabrication industry to know whether that includes Intel Integrated Foundry Services and Samsung's offerings, or just means TSMC N5 and N3)

Meta pours cash into servers and AI as ad revenue falls

Tom Womack

Oh no, an extra year before fanciest-available datacentre CPUs trickle down through the second-hand market to add to the medium-performance computing facility in my garage.

On the other hand, an enforced one-year gap on computer acquisition just as electricity bills are tripling is probably not the worst plan.

Getting that syncing feeling after an Exchange restore

Tom Womack

If the purpose of email is mostly to organise meetings, then being able to send emails which are instantly accepted or rejected into a calendar, and where the 'pick a time slot where the recipients are all free' is a function of the mail client is incredibly useful.

Arm says its Cortex-X3 CPU smokes this Intel laptop silicon

Tom Womack

Re: Girding of Loins

They've already done it - Amazon has warehouses full of its c7g Arm-based units, Apple sells Arm processors by the million.

Or is the only interpretation of "taking on Intel head-on" that you'd accept one in which Arm itself sells physical objects in the retail market to plug into sockets on motherboards, which they've been absolutely clear for twenty years they're never going to do.

Broadcom to 'focus on rapid transition to subscriptions' for VMware

Tom Womack

Re: Software as service once again

KVM? Xen? AWS is Xen, Azure is HyperV, Google Cloud is KVM ...

Cryptocurrency laundromat Blender shredded by US Treasury in sanctions first

Tom Womack

Re: Mixer services

They're really not, because keeping cryptocurrency transactions private is not a legitimate goal.

The weird lend-real-money-against-cryptocurrency industry already regards 'coins that have gone through a mixer' as unacceptable collateral; I would expect that in the medium term it will not be possible to sell for real money coins that have ever passed through a mixer.

Tesla disables in-car gaming feature that allowed play while MuskMobiles were in motion

Tom Womack

At the price charged for Teslas, and the number of GPUs they have in them anyway, wouldn't a second touchscreen in the front mounted somewhere that the passenger can see it but the driver not be a sensible approach? It would also allow the driver's touchscreen to be moved somewhere that the driver isn't having to look away from the centreline to see it.

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