Does watching TV in HD use more power than standard viewing?

No - using a larger TV to get the benefits of HD will though.

When you watch a SD programme on a HD TV the screen has the same number of pixels as when watching a HD one. The extra ones are invented by the TV by it's internal scaler.

Probably depends on the age of technology.

Some of the first HD Freeview boxes used a high 30 watts in HD mode !
Decent silicon chips should now mean little difference.

An HD chip will still require more power than an SD only one, it's the nature of the beast.

Thanks for the replies.

relative to the power consumption of even a LED TV, I am guessing that the power usage of HD vs SD by the decoder chip is negligible.

My post was in response to a comment about a Freeview box, not the TV - but an extra few watts isn't really 'negligible' in the low consumption of a modern LCD TV.

The same number of pixels are being worked regardless Sd image has to be upscaled to fit, HD processing/decode is trivial at this point...I mean really, even ipad type things do HD now.

And has nothing to do with Freeview HD - where the chip set is far more power hungry than an SD only chip set, more memory, faster clock speed etc.

As far as that goes, higher spec sets take more power for the same reasons, better and faster processing (faster in terms of the chip speed, not actual 'real' speed).

Even for a LED TV is a few percent at most.

http://reviews.cnet.com/green-tech/t...umption-chart/

In terms of annual running cost 1w approximately = £1 assuming the device is on 24x7.

I would imagine that when the IC is outputting an SD image it won't be drawing as much current to do the computation.

I do agree that this saving in power would be rather marginal as these ICs are extremely efficient.

That's a VERY old list

Pretty horrific Plasma values

If the Freeview HD chip takes an extra 5W, that's a pretty high percentage of a modern LCD/LED set.

That takes some swallowing

An extra 5W is around 10% of the total consumption of many LCD's it should be very easy to check simply watch BBC1 and check and then BBC1-HD and check. An extra 5W for 1 chip sounds far fetched to me. How much extra current does the scaler circuitry require to upscale 576i to 1080i.

How would that help?, the chip is still inside the TV and still running


Based on the relative consumptions of HD and SD Freeview boxes I thought 5W seemed a reasonable figure?. These massive complicated chips run at very high speeds, and consume considerable power.

I suggest you don't find out what the processor you're using in your computer consumes


No idea, but no extra, because again the chip is running all the time.

Under heavy load the chip will be working harder and will draw more current.

If a scaler IC is designed to be able to handle upscaling of 1080 then when producing less than that it will be under less load.

Just check a PCs output when you connect a higher res display.

Yea well how much does the freeview chip use?

If it were that power hungry it would require some insane heat sinking, heat is heat, if the chip used 50 watts it would be like cooling off a 50 watt light bulb with a heatsink and fan, no simple task, let alone in the size constraints where it would be. The numbers for such chips is trivial, else there would be a scandal. Since the things are built into tv's now, the power has to be trivial else it would require some elaborate and expensive cooling since there is no space at all inside a tv now.

I imagine the OP was asking does it use more electricity to watch HD than SD on the same HD capable TV. Which bit is not being used

From the Sony Website

Sony KDL-40EX503 (DVB-T2 HD Tuner) Home mode energy consumption 106W

Sony KDL-40CX520 (DVB-T SD Tuner) Home mode energy consumption 120W (it actually says 181W but they have mixed up shop mode and home mode)

I wouldn't have thought so, the chip 'may' use slightly less power for SD than HD, but I doubt it's much. On the same grounds, the scaler 'might' be using more power upscaling the SD though as well?.


So why compare an LED set and a CCFL one?

This is why the chip in an HD box often has a heatsink attached, where SD ones don't.

As you say, heat is heat, and chips often get HOT! - too hot to touch isn't unusual.

Yes I'm sure it does, but a heatsink attached to something in a confined environment doesn't mean much, chips have a narrow window to work in, and so thermal management is pretty normal stuff, but since it doesn't have a huge heatsink or fans, it means it doesn't use much. Look at led lightbulbs that use just a few watts, they have huge heatinks Its not quite the same, but similar enough for the principle. If say a 2-3 watt chip is in a totally confined environment of a tv, yes, you'd heatsink even that, but it would still be trivial power use. The most obvious reason the chips doesn't use a lot of power is that if they did, it would create an engineering nightmare for tv designers.

They are both CCFL

http://www.sony.co.uk/product/tv-102...TechnicalSpecs

http://www.sony.co.uk/product/tv-102...TechnicalSpecs

These are trivial things now and have been for a long time, else your iphone would burn your hand playing back 720/1080p video. Recording 1080p video on the iphone should melt the thing down by that standard

Sorry, I thought the EX were LED?, while the CX (bottom of the range cheap set) was CCFL.

Freeview HD hasn't been round 'a long time'

Yea but the chips were not made in 2001, they were made using modern processes. Decoding video is pretty standard now as well, it just doesn't make any logical sense that it would use much at all at this point. You might have had a point back in 2001 when hdtv box receivers were well..box receivers in the us....and decoding hd video was computationally expensive, now its just simply trivial.