Do "Redmere" HDMI cables introduce input lag?

Discussion in 'Displays' started by Blue_Scholar, Sep 11, 2015.

  1. Blue_Scholar

    Blue_Scholar Gawd

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    Looking to connect gaming PC to my plasma TV need about 15 feet or so of flexible thin HDMI cable. "Redmere" HDMI cables seem to be the ticket but I'm concerned about whether or not this technology introduces input lag. Does it?

    Thanks.
     
  2. kevinlekiller

    kevinlekiller n00b

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    Input lag probably has more to do with the circuits inside the monitors than the cable. From what I can see, the circuit inside those "redmere" cables is more about extending the length of the hdmi cable by making up for signal loss. If the circuit inside the cable introduces lag, it's probably a very tiny amount, negligible I bet, but without testing it's hard to say for sure.
     
  3. Polar_Fox

    Polar_Fox Limp Gawd

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    Expensive digital cables are blatant scams, especially those advertised with features aimed at improving the signal transmission.
     
  4. kevinlekiller

    kevinlekiller n00b

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    I wouldn't really say they are very expensive (30$ for 30 feet for example), they are active cables, to allow longer distance cable runs. They don't claim to improve the signal (a quote from the product page: "Active signal regeneration to ensure accurate reproduction over longer distances").

    Not trying to defend expensive cables or anything, I hate expensive cables like "Monster" as much as the next person.

    Here's a link to one of the "redmere" cables: https://www.monoprice.com/Product?c_id=102&cp_id=10255&cs_id=1025506&p_id=9430&seq=1&format=2

    They look pretty cheaply made honestly :)
     
  5. Blue_Scholar

    Blue_Scholar Gawd

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    Thanks Polar Fox for attempting to derail my thread.

    The question is not the expense but rather do they introduce input lag?

    Does anyone have any first hand experience with this in terms of gaming?
     
  6. kumquat

    kumquat [H]ardness Supreme

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    Why do you think a particular HDMI cable would introduce input lag?
     
  7. Polar_Fox

    Polar_Fox Limp Gawd

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    I have a cheap no name 20ft hdmi cable and it does the job it's supposed to do, no complaints, it doesn't come with any "signal regeneration" features though, so maybe I'm missing a lot. What kind of difference in "reproduction" are we looking at? Are there any examples on the web? :D
     
  8. kevinlekiller

    kevinlekiller n00b

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    I think up to 50 feet or so, passive hdmi cables are fine if they are well shielded, it's over 50ft there needs to be some active circuitry (some kind of amplifier to bring the signal strength back up) to keep the signal levels up.

    Edit: Wikipedia says 15 meters (49 feet). https://en.wikipedia.org/wiki/HDMI#Cables
     
  9. kevinlekiller

    kevinlekiller n00b

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    It's analog circuitry, so it would add microseconds, or even picoseconds at most of lag.
     
  10. SnowBeast

    SnowBeast [H]ard|Gawd

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    Did you read that???? It has to meet those qualifications which would include being powered. Such as my Redmere 30 Foot cables. I have done 3 home theaters in the last year so I know about going above 20 foot without powered and with. You WILL lose signal, specially if you are running any type of 3D projection over a long runs. (20 feet or more)

    And for the OP, Redmere are one directional, with one end being source(powered) and the other out to receiver on TV input.

    If you are buying for a new 4K TV over long distance, the newer powered versions are just being released do to standards changing. (4K@60hz 4:4:4 Chroma, and HDR, plus add on 3D so the bandwidth needed to go above 10Gbs/18Gbs, is going to be as high as 31Gbs in the newer HDMI spec. Above the current standard.)
     
  11. kevinlekiller

    kevinlekiller n00b

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    Yeah, not discrediting the use of active cables, trying to show Polar_Fox that they are not a gimmick to improve visual quality or whatever.
     
  12. kumquat

    kumquat [H]ardness Supreme

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    As far as I can tell, Redmere cables aren't powered. The Wikipedia article says that regular cables are fine up to 50 feet if they're well-constructed. I'm not sure where you're getting this powered stuff.

    I've installed at least 4 HDMI cables of over 25 feet and have had zero problems. All Monoprice cables, too, come to think of it.
     
  13. kevinlekiller

    kevinlekiller n00b

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    I didn't mentioned them being powerered. (Edit, I do realize you probably were refering to SnowBeast's post)

    Although they are active, they do require power, possibly from the 5v wire going through the HDMI cable, instead of some external power source, you can see an image of the circuit here: https://i.imgur.com/Xz7x35W.jpg

    Edit: From what I can gather, the idea is to make a HDMI cable that is thinner (more flexible) / cheaper costing by using thinner wire, then using that circuitry to boost up the lost signal from the thinner wire. The website with the specifications no longer exist, so I gathered this from various websites.
     
    Last edited: Sep 11, 2015
  14. Polar_Fox

    Polar_Fox Limp Gawd

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    You still don't need this type of cable just for 15ft.
     
  15. kevinlekiller

    kevinlekiller n00b

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    Yeah, that's for sure. Unless it's really cruddy quality cables.
     
  16. cbf123

    cbf123 n00b

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    The main advantage of a Redmere-type cable for shorter distances is that it allows the use of thinner conductors, which makes for a more flexible cable.

    Take a look at this comparison, for instance:
    [​IMG]
     
  17. baii

    baii Limp Gawd

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    there are fiber optic hdmi cable as well if you haven't noticed. they claim no signal lost in 1000ft.

    My guess on input lag is that the portion from hdmi cable is rather insignificant compare to the display processing time.
     
  18. JJ91284

    JJ91284 Gawd

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    I run the monoprice Redmere cables in my home theater setup with my LG OLED tv. I like them because they are extremely thin and make cable management a breeze.
     
  19. XoR

    XoR Gawd

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    To have significant amount of input lag it would be necessary to add large amounts of very fast memory buffers which would translate to higher cost and size of device. Now why would anyone add memory buffers in such device?

    No matter how data is actually transmitted inside cable it will always suffice to have very little transistor flip-flop 'memory' to manage retransmission. If there is any lag at all then it is few pixels long at most, not even one line. There is absolutely no reason to be concerned about input lag in such devices at all.
     
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