Can HDMI 1.4a (AMD 7950) do 1080p @ 240Hz?

KC21

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Hi, I have a Radeon HD 7950 and i'm wondering if I can game at 1080/240 through the card's HDMI (1.4a) port?
 
Solution


No it is not possible. 1920 (horizontal scan lines) * 1080 (vertical scan lines) * 3 (colour channels) * 8 (colour depth) * 240 (fields per second) = 11,943,936,000 or approximately 12 gigabits of data without taking into account blanking periods. This exceeds the maximum bandwidth of the HDMI 1.4 specification which is 8.16 gigabits per second.

KC21

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Why won't it run at 240fps?
 


No it is not possible. 1920 (horizontal scan lines) * 1080 (vertical scan lines) * 3 (colour channels) * 8 (colour depth) * 240 (fields per second) = 11,943,936,000 or approximately 12 gigabits of data without taking into account blanking periods. This exceeds the maximum bandwidth of the HDMI 1.4 specification which is 8.16 gigabits per second.
 
Solution


there is some headroom with 1.4a and with decent cables you can do close to 10gb per second. plenty of sources testing 4k limits with common hdmi and things working when they shouldn't prove the headroom. but this is on a case by case basis and not a guideline so individual mileage will vary.

some games like counter strike source will have its 99% frames at 299fps with a tahiti chip.
 


It's certainly true that the cables themselves may in some cases provide sufficient bandwidth (nevermind that close to 10gbps is still below the 12gbps that is needed) but getting to that point requires attaching a display that supports those timing in its EDID block or hacking the timings and hoping that it works. Standards exist for a reason and going outside of them can result in irritating problems if users get the impression that non-standard behaviour is actually standard. I prefer to avoid providing false hope.
 
^Pinhedd.... tru dat. and there are really no true 240hz monitors anyways. well, im sure you can find a very expensive nec model or something that uses a cheat to get to a true 240hz refresh... but if your looking at samsung hdtvs that say "240hz" or the sony playstation 3d ready 240hz monitor... this is a marketing lie and not even close to "computer world" refresh rates. basically the benq and asus 144hz monitors are the go to for high refresh monitors and there really isn't anything better.
 

KC21

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exactly what I wanted to hear! Thanks!