DisplayPort 2.0 Ultra High Bit Rate Cable Certification Aims To Avoid The HDMI 2.1 Debacle
by
Zak Killian
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Wednesday, March 02, 2022, 04:19 PM EDT
You may recall that HDMI 2.1 offers improved transfer rates and extra features (like variable-refresh-rate support) over previous versions of the format. If you're properly informed, you may also recall that all of those features, including the improved transfer rate, are completely optional.
The HDMI Administrator says that vendors should label all HDMI devices going forward with the latest version of the HDMI spec. This ultimately means that unscrupulous sellers pushing old HDMI cables are completely free (and in fact encouraged) to label them as "HDMI 2.1" cables, as after all, they may well work just fine with devices that are also labeled "HDMI 2.1."
It's kind of a fiasco, and it's one that VESA would rather avoid with DisplayPort. We know that because the group just announced a certification program for DisplayPort devices and cables. DisplayPort 2.0 introduces higher transfer rates known as "UHBR", or "Ultra-High Bit Rate." These higher transfer rates require superior signal integrity, and a crappy cable isn't going to cut it if you want to watch 4K120 or 8K60 content.
VESA is specifying two tiers of UHBR certification for cables: DP40 and DP80. DP40 cables must support the UHBR10 link rate on all four lanes, allowing up to 40 Gbps transfer rate. Meanwhile, DP80 cables predictably must support both UHBR13.5 and UHBR20 link rates across all four lanes, giving a maximum throughput of 80 Gbps.
Naturally, DP40 and DP80-certified cables will be fully backward-compatible with the older HBR standards. VESA also says that "full-feature" USB-C cables already support UHBR speeds, which is a little interesting. The group has already certified some DP40 and DP80 cables, and says that it's in the process of testing and certifying the first batch of USB-C to DP converter cables.