IIRC, the hand tracker modules I saw at CES and the roadshow had pass-through USB-C ports. I would be shocked if combining hand and eye tracking on-board was not possible.
EDIT: Actually, I was wrong.
Recovered Topic Heliosurge (Poster was a sock account)
As far as I understood @PimaxUSA, the first iteration of hand tracking modules wonât have that pass-through option, but a second generation is planned to have one.
Wouldnât order the hand tracking module until it is confirmed to be the version with the pass-through.
Might be a long time before that and really its not necessary. Takes two seconds to use the pt on the et module to your pc.
Source? Link please?
Sorry, I find this statement confusing. Are you saying there is a second port on the eye tracking module for the hand tracker? Given the way the hand tracker snaps in, that doesnât make sense to me. I would think the eye tracker would have to plug into a USBC port on the bottom of the hand tracker.
Sorry too many abbreviations for the late hour 
So do you mean that it is easy to plug in either the eye tracking module or hand tracking by unplugging one and connecting the other or that the hand tracking should be connected to the PC directly via another 5m usb cable?
Yeah the ET has two ports, one in the front and one on the side. If you want both same time on X you just run the side port to your pcâs usb and plug the HT in as normal.
So to be clear, this means a separate 5m USB cable?
In hindsight, I guess that makes sense due to the bandwidth requirements, but I think a lot of people will be displeased.
Ok, understood. Another (long) cable then, hm. Might probably wait for the hand tracking module with the pass-through port then unless hand tracking gets widely spread before that.
Yeah a 5m USB cable. But really the 99.9% of the time since no software uses both at the same time you just remove the HT and insert the patch cord. This is far less of a significant deal than it seems.
Isnât eye tracking something you always want to have enabled once you have a gpu that supports DFR?
Ah. Unfortunate.
@PimaxUSA
Please ensure on-headset or wireless USB3 connectivity is available for these modules before 8kX wireless support.
Hand tracking is the great enabler for combining HOTAS/simpit, flight deck switches, and roomscale gameplay, seamlessly. Eye tracking is needed for hands-on menu navigation during intense situations. This combination is probably essential for games like Star Citizen to support the best possible VR experience.
Already, the difficulty of combining these modes was the âofficial reasonâ Frontier Developments is dropping VR support for Elite Dangerous with their âOdysseyâ update. And No Manâs Sky already supports a similar mix of gameplay, though imperfectly.
Having an extra 5m cable to the headset, while tolerable to me, is likely to reduce consumer update of the eyetracking module, which will further hurt its software support. Keep in mind lengthy robust USB3 cables are typically quite heavy due to the number of fully shielded twisted pairs. That is a lot of metal and plastic.
@PimaxUSA - is there already an ETA on the 8kX with the eye tracking module intregrated? This one would still have the lower free USB port for hand tracking, right?
Iâm confused by this statement. I thought eye tracking was at driver level? Wouldnât a game which supports hand tracking also support eye tracking because its software agnostic?
For simmers eye tracking and hand tracking are hugely important, I am interested in BOTH modules.
Forcing us to plug the hand tracking into the pc is a huge oversight imo and makes me think these modules are nothing but an afterthought for PimaxâŚ
Probably not I am guessing. In the Pimax Now event and subsequent forum thread, it was stated that 3X better performance resulted from using USB3. The hand tracker module I would expect to be even more bandwidth hungry, and that is probably way too much for one set of USB3 data lines.
Thus, separate cable, unless more wireless/optical stuff is added. By the way, USB3 active optical cables may be the best bet to minimize weight with such a separate cable.
Personally, I donât care. I plan to use the 8kX headset tethered for the forseeable future, and I donât mind the weight of a USB3 cable. The possibility of a fiber optic 8kX cable is more interesting to me, since I will probably have much less to worry about stepping on it.
Yes, but apparently there isnât any software that happens to support both. Like, if Elite Dangerous supported the hand tracker, we already know it wouldnât do anything with the eye tracker directly and doesnât support FFR much less DFR.
That said, I doubt there is no software with support for both. DCS World might support the hand tracker, and supports FFR, so as an example, in theory, that might support both modules.
Hm, if eye tracking and hand tracking donât work over one wire, how does it work for the 8k+&Co then? Or canât hand tracking and eye tracking work together on the other Pimax headsets also?
Adding a very small, heighweight usb hub with velcro to the game might also be an option. But then things really start to feel a little DIY prototype style 
If the hand tracking turns out to become a must have that might be what I might tryâŚ
Well better than not having the option at all (which is the default for most other headsets on the market).
I suspect they will work, but degraded, due to less bandwidth. I personally would use another cable if there was even any possible risk of extra lag in hand tracking or eye tracking.
If there is sufficient power and bandwidth, that will probably work. As I stated though, less than full USB3 bandwidth for either device is likely to degrade things.
All of which brings up another interesting problem.
You may need separate dedicated USB3 controllers for each module to work optimally.
Many of the ports on your motherboard are probably sharing a single controller with as many as four ports. So this will be similar to the Oculus CV1, where getting the best experience with three or more cameras, means buying installing a dedicated ~$80 PCI-E card (which I still have installed today) on a motherboard with adequate PCI-E lanes (less of a problem going forward).
Which if you install things wrong, would make DFR useless because now your GPU is starved for bandwidth, or the eye tracker latency just went up.
At best, I think end users are going to need a paper document slipped in with their eye tracker and hand tracker modules to the effect of âmust be connected to dedicated USB3 controller not sharing GPU PCI-E lanes for best resultsâ.
Which in fact, IIRC, is what Oculus did for their headset and constellation sensors. Actually they went a step further and showed a warning popup if something odd was being done, like having USB3 port controllers not specifically on their allow list.
Any chance the optical cable would have enough throughput that its HMD-end tranceiver could multiplex two USB connectors with the required bandwidth, on top of the 75Hz-or-maybe-more refresh rate 2x4k video?
Is bandwidth really a problem for eye-tracking and hand-tracking? Arenât both doing the video to sensor data conversion in hardware?
If two dedicated USB3 cards would be necessary then most computers would disqualify, these use internal hubs in almost all cases.
Letâs wait, they have to clarify whether or not both modules work together for the 8k+&Co people anyways. If it works for these it should also work for the 8kX with a hub - or more elegantly a new hand-module revision with pass-through.
Yes, it definitely is.
No.
For the eye tracker, no, PimaxUSA has made that explicitly clear when stating latency improved 3X with USB3 bandwidth. For the hand tracker, it is highly unlikely - the algorithms required just to do the stereoscopic camera depth determination are extremely intensive, far beyond what would be done on an embedded processor if there was any alternative.
No. Hubs, ok. Other things plugged in to same USB3 hub - though possibly not low bandwidth keyboards/HOTAS/etc - not ok.