I call ******** on your cable. All display port cables should be fine, except those labeled as RBR (they only go to 1080P and are for projectors). There is no such thing as a "DisplayPort 1.2" cable, all standard DisplayPort cables support RBR, HBR (High Bit Rate), and HBR2 (High Bit Rate 2), which can support 4K at 60Hz, or up to four 1080p displays using multi-stream.
Just make sure the cable is DisplayPort certified.
And you'd make that call how? By making the same mistake I did by reading "stuff" on the internet? No offense, but I bought two just to try out after "lag" and "stutter" and "overheating" were just some of the words we used every day in my offices, no complaints from my gallery for 2 months now, not one.
Read posts by others that gripe about lag - none of our Macs or Win PCs lag. Read others post about overheating machines or "sleep issues" - our PCs and Macs run cooler (I run iStat Menus, so I can empirically compare before and after the switch). All of the other DP cables we've used return power on Pin 20, but Apple's TB cable (DP 1.1a
compliant) and Accell's DP cables (DP 1.1a or 1.2
compliant) do not return power on Pin 20 - please, Google it for yourself. I used my multimeter on my cables, empirically backing the manufacturer's statements.
Read about my earlier posts and those of others in the Dell P2715Q thread about using SwitchResX and EDID hacks to get that, and the Dell P2415Q displays working well. I had to clean install OS X on my Mac a couple of months ago, and did not install either of these hacks, simply connected the two Dells to my Mac with the Accell cables and it just worked, and I can see color profiles and resolutions in the Displays Pref Pane now that I needed a hack and utility to get them to work.
My Macs and my PCs now correctly read the EDID of the Dells, the BenQs, and the Eizos we're using - we're not running any more hacks or utilities to get our displays to work with our computers.
And, maybe you didn't know that the per-channel throughput of the Accell cable is greater than those cheaper "compatible" cables. Checked on our PCs.
You're entitled to your opinion. I don't care, we're using Accell cables now for our displays, and my techs could tell the difference - I did a blind test with 5 of them and all noticed a difference in performance. There's a big difference, to me, between the words "compatible", "certified", and "compliant". Buy one from Amazon, they've got a great return policy... I'm happy with my purchases. I'm not defending Accell, but I'm a happy customer.