Question Displayport 2.1a and 2.1b

Elliah246

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Feb 11, 2024
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DP 2.1a vs 2.1b
What's the difference?
AMD RX 9070 XT uses 2.1a but nvidia use 2.1b or? What does the 50 series and 40 series use?
Can the 9070 XT handle UHBR20 ? Can the 5070 Do it?
 
The 2.1b variant that is included with Nvidia 50-series cards and was announced at CES supports longer cables for UHBR20, which stands for Ultra-High Bit Rate at 20Gb/s per-lane, with four lanes on tap for up to 80Gb/s of bandwidth.

The new cables were unveiled at CES by VESA, which is the industry group that ratifies new display standards. The new cables are called DP80LL, with the two L’s in the name signifying “low loss” and the rest of the name translating to DisplayPort 80Gb/s. Previously, there were just passive UHBR20 cables that were restricted to one meter in length, but the new DP80LL cables are active, and can be up to three meters in length. Suffice to say Nvidia 50-series owners should not have a problem with bandwidth when trying to game at 4K using DisplayPort 2.1b, but note you will need a DP80LL cable to enable high-bandwidth transmission at three meters.
Source: https://www.corsair.com/us/en/explo...21b-and-hdmi-21b-everything-you-need-to-know/

What does the 50 series and 40 series use?
RTX 40-series: DP 1.4a
RTX 50-series: DP 2.1b

DP 2.1 and 2.1a wasn't out when RTX 40-series released.

Can the 9070 XT handle UHBR20 ? Can the 5070 Do it?
UHBR20 is just bandwidth and not the actual measure of GPU performance.

Look UHBR20 as 8 lane wide highway and UHBR10 as 4 lane wide highway. Just because UHBR20 can sustain more cars driven at any given moment (more data throughput), doesn't mean that the cars on the highway drive faster or that there are more cars in the first place. It's just overhead for things to come.

E.g DP 2.1b can do 4K at 480 Hz. NONE of the current GPUs out there, can do gaming on 4K at 480 Hz. RTX 5090, at best, gets ~100 FPS/Hz on 4K.
 
40 series uses 1.4a

2.1a officially supports UHBR 13.5
2.1b officially supports UHBR 20

so basically just an upshift in the max refresh rate available in all resolutions. 4K 240hz 10bit should be doable on 2.1b, and a maybe on 2.1a.

That said, at that point you are very much dependent on the monitor and cable.
 
40 series uses 1.4a

2.1a officially supports UHBR 13.5
2.1b officially supports UHBR 20

so basically just an upshift in the max refresh rate available in all resolutions. 4K 240hz 10bit should be doable on 2.1b, and a maybe on 2.1a.

That said, at that point you are very much dependent on the monitor and cable.
Could you link a media for resolution stats?

Will 2560x1440 (2k) @240hz work WITHOUT DSC using and AMD 9070 XT with DP 2.1a ?
 
Could you link a media for resolution stats?
Here is a link i found when i initially wrote my reply but i didn't post it then.
Article: https://www.pcworld.com/article/619...he-new-ultra-high-bit-rate-certification.html

Will 2560x1440 (2k) @240hz work WITHOUT DSC using and AMD 9070 XT with DP 2.1a ?
Also, just found this;
link: https://linustechtips.com/topic/729232-guide-to-display-cables-adapters-v2/

You need to fill out output and input ports to see the data. Which then is shown in nice table format.
At the bottom of 1st reply is also a Calculator that you can use, to get your answer.