Gadgetory

hey Ron I'm Steve from gamers Nexis thought net and first I'll check out the new set pretty sweet so today we're talking about HDMI as an interface hopefully debunking a couple of myths answering some questions surrounding HDMI because it can be a bit confusing with all the different video interfaces out there first of all what is HDMI HDMI is a video interface that can transmit interestingly video data can also do audio data and it can do data data so when I say that I mean if you have a USB interface on your device monitor TV or otherwise HDMI is capable of transmitting receiving data through the HDMI interface for USB devices or similar devices HDMI can also do this for audio if your monitor has speakers built into it instead of using a 3.5 millimeter jack you can actually tell the computer and monitor to communicate with one another using audio down the HDMI cable so the main advantage here is that it makes cabling a bit simpler if you're using a setup like that now HDMI at a more spec level is a 19 pin interface you can see a chart of that here and the pin out includes a lot of pins for what's called TMDs lines so what is TMDs TMDs stands for transition minimized differential signaling and what that means is it's a it's a method for reducing EMI crosstalk things like that and this is done by taking a signal splitting it down to lines to wires and one is positive one is negative at the end of the line when they are merged again into one signal there's effectively a parity check where the system can look at it say this data is static data or EMI or interference impedance crosstalk whatever you want to call it and does not belong in the signal and will muddy our resulting image or audio or what have you and TMDs takes that looks at it strips out anything that does not belong and then you get your cleaner signal so that's what those do there are three TMDs channels in HDMI 2.0 which is the most recent HDMI interface hdmi 2.0 with three TMDs channels each one is capable of doing six gigabits per second so you have an 18 gigabits per second 6 times 3 total throughput potential on hdmi 2.0 as an interface for comparison purposes hdmi 1.4 and 1.4 b which are among the most prominent interfaces on the recent market are capable of doing 10 point 2 gigabits per second with a 340 megahertz pixel clock the hdmi 2.0 pixel clock is 600 megahertz and this is actually really important for high resolution gaming and we're going to talk about why right now to see how useful that 600 megahertz pixel clock is we can do some basic math take a 4k display as an example that is 4096 pixels by 2160 pixels you multiply those you get about eight point eight million pixels give or take a couple at the end there and eight point eight million pixels is a lot of data being transmitted it's doing that every frame there are 60 frames per second or 60 Hertz in this case we have a refresh rate 60 times per second times eight point eight million equals about 530 million 530 million or five hundred thirty megahertz fixed within our 600 megahertz budget for the pixel clock on HDMI 2.0 as an interface so that means that in this instance we're capable of transmitting 4k at sixty Hertz which was the big deal with the HDMI 2.0 launch now for HDMI 1.4 there is a common misconception where users perceive that the interface is capable of transmitting a 1080p output at 120 Hertz this is true and not true at the same time so to clarify things for everyone it is capable of doing 1080p at 120 Hertz but only for 3d and that's because it's cloning the data packet and you're stacking it for three-dimensional use if you're doing some kind of 3d vision setup or similar in this case for 2d use you're stuck at 60 Hertz 1080p on HDMI 1.4 so then can hdmi 2.0 do 1080p at a higher frequency like 120 or 140 for hertz well if we do the math again on 1080 1920 by 1080 times 60 or times 120 you can see that the pixel rate actually fits within the allowance the Headroom provided by the pixel clock and the throughput potential of the three TMDs channels however there are a lot of things in flux here and just because it fits within that specification doesn't mean that you're going to get 120 Hertz 144 Hertz on your new monitor so here's the things to look out for first of all the video card has to support HDMI 2.0 a lot of video cards do not support this including some newer ones the monitor itself or device whatever the receiving device is receiving the output from the video card must not only support HDMI 2.0 but it has to support it at the frequency and resolution that you desire so you need to check the manufacturer's specifications page and see if it's within the spec one big end important note you do not need a so-called hdmi 2.0 cable because the cable itself didn't change and that's something that's true for a lot of interface updates where SATA for example SATA uses the same cable for SATA 3 SATA 2 SATA one they all perform the same they all have the same throughput it's just the interface that matters on the component and the device through which you are transmitting your data so hdmi 2.0 cables quote-unquote are not necessary for setting up an hdmi 2.0 device now in general it is very uncommon for displays to support a higher frequency output using hdmi at any resolution so we strongly recommend using DisplayPort or DVI dual link cables for your higher refresh rate needs when you're gaming and ultimately HDMI is more of a consumer interface it's more meant and was originally built for things like TVs and viewing things where you don't need a very high refresh rate generally and for gaming you're going to want to use DisplayPort which is still rising gain market share a rapidly or DVI dual link and even though DVI feels old at this point dual link cables which we have another video about have a very high throughput potential and that allows them to do the higher frequencies like 120 Hertz at 1080 for example to make sure a cable you buy is actually dual link DVI you need to check our previous video just search the channel for DVI you should find it because the fatter cables are the ones that are DVI dual link the skinny or DVI cables are not going to be dual link even if sometimes they're sold on Amazon or Newegg as such and the reason they can get away with calling a single link DVI cable dual link is because they'll have the pins in the header but they're not wired so that means it's not going to work but that's another discussion that's in our previous video as far as HDMI no hdmi 1.4 does not support 120 Hertz without using 3d so in 2d you don't get 120 Hertz at 1080 that answers that hdmi 2.0 primarily supports higher resolutions like 4k at 60 and then if you want anything else you need to very closely look at your video card and then the monitor itself must support whatever it is you're seeking so check on a per device basis don't just assume that hdmi 2.0 is going to get the job done because it's not really that simple when it comes to this particular interface that is all for this video hit the patreon link in the post role if you like this kind of content and help us out we picked up I think two new patron backers is our patreon backers rather in the last couple of days here so huge thanks to those of you who have contributed helps us do awesome things like this right behind me and and stay independent in our production so that's all for this time I will see you all next time