What Pin 20 does
A DisplayPort connector has 20 pins. Pin 20 is labeled DP_PWR. It delivers power at 3.3V and 500mA. That has a legitimate purpose. VESA's FAQ explains that a DisplayPort source such as a notebook supplies power at the plug to run an external adapter. In that role it feeds the small electronics in active dongles, so those dongles don't need a separate power supply.
The trouble starts when a plain DP-to-DP cable carries Pin 20 from one end to the other. In that case the power line on the PC's graphics card is tied directly to the same line on the monitor. According to a forum explanation quoted on Tom's Hardware, both source and sink are supposed to supply 3.3V on that pin. The same post argues it's impossible for both pins to sit at exactly the same voltage, so joining them effectively creates a short-circuit condition.
What the standard says
The rule is about wiring, not about the connector itself. A passage of the VESA spec, quoted in a Widescreen Gaming Forum thread, says a standard DisplayPort cable must have no wire for the DP_PWR pin. The same passage says only captive cables supplied with cable-powered branch devices, or cables permanently attached to sinks, may carry that wire.
The connector still has a Pin 20 contact. Dell describes its own approach this way: the 20th pin connection remains in the connector, but it isn't internally connected inside the cable. So the common claim that only 19 pins are functional is imprecise. The cable simply must not route that one line through.
What can go wrong
Dell's support article says graphics card failures have been traced to 3.3-volt DC power returning to the graphics adapter through pin 20. Dell says its engineers solved this by removing the 20th wire in Dell DisplayPort cables. The article lists several Dell docks, including the WD15, WD19 variants and WD22TB4.
The failure mode is easiest to see when the PC is off. Cable vendor Cable Chick says monitors are never really off in standby, so they feed power out to the graphics card when it isn't expecting any. Reported symptoms vary and mostly come from user and vendor accounts, not controlled testing:
- Ghost power after shutdown. A Tom's Hardware poster described case LEDs staying lit after shutdown and the PC refusing to start until the DP cable was unplugged.
- BIOS weirdness. One builder described BIOS settings resetting, the clock jumping to the year 2300, and repeated POSTs before video appeared. The builder's explanation was that the monitor was backdriving the system, feeding power through the graphics card over PCIe to the motherboard. Swapping in a cable that doesn't connect DP_PWR fixed it.
- Possible hardware damage. Dell's graphics-card failure note is the strongest documented example.
Where the BGR story overreaches
BGR's piece is right that a miswired cable is a hazard. A few of its claims go further than the evidence does.
- Slowdown is not a documented symptom. BGR suggests that a PC that slows down rapidly or fails to boot has a "decent chance" of a bad DP cable. The reports above describe backfeed symptoms: no-boot, ghost power, BIOS resets and card failures. None of them describes generic slowdown. Treat a slow PC as a software, thermal or storage problem first.
- "Cheap" doesn't mean "dangerous." The issue is wiring compliance, not price. VESA's guidance notes that you don't get a "better" picture from a more expensive cable, but a poor-quality cable can cause data errors and visible corruption. A budget cable that follows the spec is fine. An expensive one that doesn't is not.
- Newer hardware is less exposed. Two cable vendors say a graphics card made after 2017 probably isn't affected. Cable Chick says a card produced after 2017 probably isn't affected. These are vendor claims, so treat them as a rough guide and not a guarantee.
- The "death pin" label is informal. I found no standards body using it. It's a catchy nickname.
How to buy and troubleshoot
- Buy a certified cable. VESA's advice is to buy from a reputable brand or choose a cable that is DisplayPort certified, which you can check in the listings on VESA's site. That is more reliable than BGR's suggestion to run a Google search and trust the AI summary.
- Match the cable to your bandwidth needs. All certified cables support HBR2, which handles 4K at 60Hz. DP8K-certified cables are built for the highest-bandwidth modes. That is a separate question from Pin 20, but it matters if you're buying for a high-refresh 4K display.
- Read reviews with a skeptical eye. BGR's tip to read the negative reviews first is sensible for any unbranded cable bought online.
- If a PC acts strangely after shutdown, power everything down and unplug the DP cable. Then try a known-good certified cable. If the symptom goes away, the old cable is the likely culprit. If it doesn't, look elsewhere.
- Don't modify cables. Don't cut wires or short pins. If you suspect hardware damage, get qualified service.
Don't confuse this with other connections
- Active adapters are different. A DP-to-HDMI or DP-to-VGA adapter is meant to use Pin 20 power. That is by design and isn't a defect.
- USB-C video is a separate case. VESA describes DisplayPort over USB-C as carrying video, USB data and power over the same cable under its Alt Mode rules. The Pin 20 wiring rule for full-size DP cables shouldn't be applied to USB-C cables.
- Docks and monitors with captive cables can legitimately wire the pin, per the spec exception above.
Bottom line
The Pin 20 problem is real, documented by Dell and long discussed by PC builders, and it comes down to one wire that shouldn't be there. It is rarely the cause of a vaguely sluggish PC. If you're building or upgrading a gaming or workstation setup, spend a few extra dollars on a certified DisplayPort cable from a known brand. A cable that complies with the standard is cheap protection for a graphics card that isn't.