why does an unchanging monitor receive 6GB of data every second across a big fat cable?

Why does an unchanging monitor receive 6GB of data every second?  The exact resolution and refresh rate and color depth do not matter (the above is for 8k@60Hz with 24 bit color): the point is, if the picture isn't changing, wouldn't a better rate be approximately zero, rather than being a very high amount?

The full frame data is sent with every frame.  It's mad.

With some remanence in the monitor, just updates could be sent.  Nothing complicated.  Initially it could just be "picture changed here's full frame".  Then, in cases where picture no change, not much data need be sent.  Can improve on this, but keeping in mind keep it simple, and keep it suitable for hardware.

The hdmi (or whatever) PHY at the computer end, plus the cable, and receiving terminal at the monitor, can all be seen as part of the system driving a volatile hardware panel, but a system notionally internal to the monitor.  So you want a box that can do this and attach to the back of the monitor and pretend to be part of the monitor, and a protocol for talking to that box, and a computer that outputs that, and things are starting to head in the right direction.

Comments

Post a Comment

Popular posts from this blog

the persistent idiocy of "privileged ports" on Unix

TCP and UDP have ports.  These are 16 bit; there are 65535 or so per IP address. These protocols don't care to differentiate between the ports.  Elsewhere, IANA presumes to operate a process to allocate "well-known" ports in the range 1-1023, "registered ports" in the range 1024-49151, and to reserve the remainder, 49152–65535, for "ephemeral" ports.  The caller end has to have a port, which is how replies get back within the virtual connection, and these are conventionally picked from the ephemeral range by the OS's networking stack. The whole idea of ports is ridiculous, because it allows ISPs to arse around presuming to decide which services they will "not allow".  Anything that allows IPSs to do anything other than shift opaque packets will allow ISPs to meddle and break things, and due to the Law of Meddling, if they can, they will.  I am currently working around an issue with Claro, a pretend ISP, blocking port 5060, allocated to SI
Read more

easyjet: repeated entry of information they already have

Image
As I observed earlier today, airline web sites are obsessed with making people re-enter information, apparently arbitrarily. The following seems to be required for Easyjet, for an "existing" customer relationship, every time: country of residence selected from big list, involving skidding around on the screen that makes the victim feel sick should be remembered. If it has to be changed, should be type-and-choose victim is taunted with the text "tell us about you", when they thought they had logged in form with the following on one page: business / leisure title, first name, last name, age there is a button to "copy from contact details", but this doesn't do the "age" field.  Since they have my date of birth, they are of course able to calculate my age.  As well, the only values for this field are "18+", "17", or "16".  Is it a deliberate decision, to not fill this field based on the customer data, and to make the
Read more

Guernsey Waste in incorrect bag-rejection horror May 6th, 2024

Image
The rubbish collection folk at my new place seem pickier than at other places on Guernsey. Last week, they removed some card packaging that I'd included in the card and paper (plastic) clear bag, and left it on the lane.  This week, they have attached a rejection label entitled "Polite Notice".  Just like modern software-engineered error messages (see attached tag "extremely_general_error_handling"), this does not give a specific reason why the bag was rejected, but instead lists miscellaneous possible "reasons", leaving the victim guessing, or perhaps trying to follow a process of elimination. In this case, some possible reasons, which the label does not claim to be exhaustive ("was most likely because ..."), and of which none apply, are: (i) "did not have the required payment sticker" -- no, I applied to 90 litre sticker; or  (ii) (a) "too heavy" -- no, I estimate it was 3kg, and I easily supported the bag's weight o
Read more