Probably a stupid question, but looking at the theoretical/actual bandwidth numbers it's clear that DisplayPort is still only using 8/10 bit encoding. Why haven't they switched to a more efficient one like 128/130 that would reduce the encoding overhead from 20% of the total bandwidth to 1.5%
Disappointing. DP1.3 and DP1.4 only have actual raw bandwidth for around 4k@90 with 10 bit colors. Anything beyond that is through the mathematically LOSSY DSC/Display Stream Compression feature. DP 1.4 really only added features for TV/movie watching. It is not for gamers, it is not for professionals. It does not deliver your actual pixels.
Insane to pay $5k for an 8K TV and the insane price this cable wants, just to not get your actual pixels.
A lot of games don't do well with bitrates less than 100 Mbps because of how fast the motion is. That's hardly an issue when we're talking about squeezing 120 Gbps into a 40 Gbps link. Display compression is where display industries are headed because it's not worth it to make a stupidly expensive interconnect just to keep up with display resolution.
The encoding overhead is for forward error correction (FEC). Decreasing the FEC overhead means that to reliably decode the signal, the signal quality needs to be higher. Going from 8/10 to 128/130 means it needs to be MUCH higher.
To achieve that requires more expensive and thicker cables with better shielding, shorter maximum cable lengths, higher signal power transmitted over the cable, or other tradeoffs.
8b10b is not FEC. Its for DC line balancing and guaranteeing enough transitions to lock onto the signal. As well as having extra control characters for alignment.
Oooh, cool, Now I can keep my gaming PC at home while I'm in my brother's house next to me.. no damn, I'll need another cable for USB as the Logitech wireless can't reach that range.
But really, If these cables ( at least the HDMI ones ) will become cheaper then they will be good alternative to HDMI over Cat6 solutions we're using to connect the PC's to living room TV's.
I did this for a two years starting five years ago. First box didn't work. Second box worked but signal still dropped link once every few hours. 100 foot cat 5 unshielded.
This is only useful if you need 8K. Monoprice will sell you a 100m long optical HDMI cable that does 4K60 for $135, or if you need it to do all that but also 4:4:4 and 10-bit, for $350.
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DanNeely - Wednesday, March 29, 2017 - link
Probably a stupid question, but looking at the theoretical/actual bandwidth numbers it's clear that DisplayPort is still only using 8/10 bit encoding. Why haven't they switched to a more efficient one like 128/130 that would reduce the encoding overhead from 20% of the total bandwidth to 1.5%fanofanand - Wednesday, March 29, 2017 - link
That's DisplayPort 1.5.Kidding (sort of) but that's a good question, I would like to know this as well.
blahsaysblah - Wednesday, March 29, 2017 - link
Disappointing. DP1.3 and DP1.4 only have actual raw bandwidth for around 4k@90 with 10 bit colors. Anything beyond that is through the mathematically LOSSY DSC/Display Stream Compression feature. DP 1.4 really only added features for TV/movie watching. It is not for gamers, it is not for professionals. It does not deliver your actual pixels.Insane to pay $5k for an 8K TV and the insane price this cable wants, just to not get your actual pixels.
cbm80 - Wednesday, March 29, 2017 - link
DSC doesn't add significant latency. It's fine for gaming.willis936 - Thursday, March 30, 2017 - link
A lot of games don't do well with bitrates less than 100 Mbps because of how fast the motion is. That's hardly an issue when we're talking about squeezing 120 Gbps into a 40 Gbps link. Display compression is where display industries are headed because it's not worth it to make a stupidly expensive interconnect just to keep up with display resolution.Etsp - Thursday, March 30, 2017 - link
The encoding overhead is for forward error correction (FEC). Decreasing the FEC overhead means that to reliably decode the signal, the signal quality needs to be higher. Going from 8/10 to 128/130 means it needs to be MUCH higher.To achieve that requires more expensive and thicker cables with better shielding, shorter maximum cable lengths, higher signal power transmitted over the cable, or other tradeoffs.
HarrietTheGuy - Saturday, April 1, 2017 - link
8b10b is not FEC. Its for DC line balancing and guaranteeing enough transitions to lock onto the signal. As well as having extra control characters for alignment.BrokenCrayons - Wednesday, March 29, 2017 - link
Only $800? Best Buy is not impressed.solipsism - Wednesday, March 29, 2017 - link
Wow! People are complaining that a 100 meter DisplayPort cable costs too much. If you need this cable, then the cost isn't going to be an issue.p1esk - Wednesday, March 29, 2017 - link
People are complaining because you can buy 30m 40Gb Cisco optical cable for $180: http://www.fs.com/products/40098.htmlRailgun - Thursday, March 30, 2017 - link
What the hell does a 3x shorter length cable of a completely different technology have to do with this?However, I get your point.
p1esk - Thursday, March 30, 2017 - link
The article mentioned 30m cable for $800, so that's what I'm comparing to. As for technology, the Cisco cable is designed to be almost twice faster.lazarpandar - Wednesday, March 29, 2017 - link
I don't actually see anybody complaining.. so please get off your high horse. You're arguing against nobody.SirMaster - Thursday, March 30, 2017 - link
It is expensive for what it is.$800 for a 328ft optical DP with 25.92gbit/s while you can get an 18gbit/s 330ft optical HDMI for only $135.
https://www.monoprice.com/product?p_id=13702
p1esk - Thursday, March 30, 2017 - link
It's $800 for 30m cable. 100m is likely to be more expensive.zodiacfml - Wednesday, March 29, 2017 - link
LOL, I thought this is going to be $800. I guess, twice that.Xajel - Thursday, March 30, 2017 - link
Oooh, cool, Now I can keep my gaming PC at home while I'm in my brother's house next to me.. no damn, I'll need another cable for USB as the Logitech wireless can't reach that range.But really, If these cables ( at least the HDMI ones ) will become cheaper then they will be good alternative to HDMI over Cat6 solutions we're using to connect the PC's to living room TV's.
willis936 - Thursday, March 30, 2017 - link
I did this for a two years starting five years ago. First box didn't work. Second box worked but signal still dropped link once every few hours. 100 foot cat 5 unshielded.willis936 - Thursday, March 30, 2017 - link
1080p 60. The box was $50 (I think. Maybe $80 idr).dstarr3 - Thursday, March 30, 2017 - link
I doubt these are in-wall rated.Guspaz - Thursday, March 30, 2017 - link
This is only useful if you need 8K. Monoprice will sell you a 100m long optical HDMI cable that does 4K60 for $135, or if you need it to do all that but also 4:4:4 and 10-bit, for $350.echobrown2017 - Sunday, October 8, 2017 - link
30m cable for $800 seems too expensive, actually you can buy 30m 40G QSFP+ Active Optical Cable for only $160:https://www.infiberone.com/product/3415.html.