HDMI Cable Testing Results

We set up a simple grid to document our test results for the various cables submitted. Unfortunately, not every manufacturer puts out cables in identical lengths, so you'll need to interpret the results creatively, understanding that if a cable passes 4m, but fails 10m, we don't know for certain whether it would pass at 5m or 7.5m, though you can get a feel for the results after measuring a bunch of cables and seeing endless patterns and trends. This means that if one manufacturer passes at 4m, and another fails at 5m, you may be looking at identical results if the 4m cable had been extended another meter. We'll provide more analysis below.

What Do All Those Numbers Mean?

It's not as confusing as you think. We did 5 different tests, largely because the computer was already preconfigured and also because it took care of the three major tests I was interested in and added two more for good measure - one on the low end, and another on the high end. To start, we took 742.5Mbit/s per channel which tells us if a cable will pass plain old 720p or 1080i. The next step up was 1080p, which has an effective speed of 1.485Gbit/s per channel (by "per channel" we mean for each of the red, green and blue channels that carry the bulk of the information in an HDMI cable). Typically, you'll see cables and HDMI-equipped products designed to handle this type of data spec'd at 1.65 Gbps. Next up was the new 1080p at 12-bit (Deep Color). This is both significant and superfluous. Significant because HDMI 1.3-enabled products all carry HDMI chipsets that can handle data rates of 2.23Gbit/s (see this excellent article for a nice tech overview of HDMI 1.3). Superfluous because there are currently no Deep Color sources which are in any sort of practical use in home theaters today (nor are they expected in the near future, save a few HDV cams and possibly some 'as-yet-unreleased' PS3 video games). The first of the final two tests measured the ability to pass the actual maximum HDMI 1.3 spec limits (and realize the NO electronics manufacturer supports this since all current HDMI chipsets are limited to 2.23 Gbit/s speeds). This is a future-ready test.

Monster also added a fifth and final test which they described as being the equivalent (mathematically) of 1080p at 120Hz. While I seriously doubt anything except possibly a gaming system in a PC-rig will ever exceed 60Hz to a display, it's neat to see how cables collapse under a future format. Given the proclivity for HDMI Licensing to spontaneously change their spec - to the collective "Here we go again" sigh of the entire industry - this isn't entirely unreasonable for the future.

The Objective HDMI Cable Test Results

*For reasons unknown to us, some manufacturers like to express the data rate as an aggregate number which combines the three primary high-speed data channels. In our opinion it's the "per channel" number that is significant. After all, we don't say that a stereo amplifier has a frequency bandwidth of 40kHz (if/when in fact each channel has a bandwidth of 20kHz.) In an attempt to be as thorough and helpful as possible, we have added the aggregate numbers to our chart as well.

What Does 'Fail' Mean?

It's important to define what we mean by "Fail'. The indicators above deal with the eye pattern on the Tektronix Digital Serial Analyzer. A 'Fail' on this chart does not necessarily mean that the cable will not pass the signal in the real world. In fact, see my Subjective summary below for some real "eye" openers (no pun intended… yes it was). The reason, quite simply, is that various electronics components have different levels of active compensation built in to help EQ incoming signals and help restructure HDMI signals into a more reliable stream. The axe swings the other way as well - we have no reason to believe the cables will reliably and consistently pass a signal to all types of components if they do not pass the eye pattern test above.

Every cable over 10 meters failed to pass 1080p, even at 8-bit, though Monster claims their m1000 Series can do just about anything (they didn't provide a cable over 10m to test and they don't sell it at lengths above 25 feet). At 10 meters the Monster Cable 700HD and 1000HD passes 8-bit, and we added Blue Jeans Cable (30 feet actually) and DVIGear. Blue Jeans, incidentally, uses a Belden-made HDMI cable. When we increased the bits to simulate 1080p at 12-bit Deep Color (similar to what's available in most HDMI 1.3a-rated products today) most manufacturers had to drop back to 5 meters to pass the signal. Blue Jeans passed it at 30 feet, but DVIGear requires their active cable solution to do a full 10 meters. Monster Cables' 1000HD cable also passed 1080p at 12-bit with no issues.