Sorry for the late response. It was Sunday night in Shanghai.
The Pimax hardware team is focusing on building the new V4 prototype, so we asked our new representatives to handle the NYVR roadshow. The refresh rate feature is mainly related to hardware and firmware, but the reps at SFVR do not have very strong hardware background, their explainations would be insuffient or inaccurate. In fact, It’s their first time to travel to the US.
There’s some misunderstanding because of the language and culture differences, and it's our fault not to sync up in time with the staffs in NYVR about the new progress. Let’s try to reveal more details regarding the refresh rate here.
Scenario 1: without “brain-warp”
Our HW system supports 90Hz, including the bandwidth of DP \processor\ driver IC. As you know, our original solution is 2*HDMI, and then we moved to 1*DP. These two solutions are very different.
The games already can run at 90Hz on the original solution (not very stable, we have to spend around 1 hour to set up the demo kit.) The stability of high refresh rate (>85Hz) is still a little bit unstable in the new DP solution in V3 prototype, so we decided to lower the refresh rate to 75Hz for the new public demos.
We are currently conducting tests for 75Hz to 85Hz. The 82Hz is already passed the initial test, now we move on to optimize the prototype to 85Hz, and do more compatibility and stability test.
90Hz is the upper limit of the whole system. The hardware reasons that may drop the refresh rate: the clock rate, cable length, display adapter FPC, EMI desense issue, Contact impedance from different Video Card’s DP connectors .......
The stability is so important because our HMD need to work well with thousands of different computers.
Before we can give a clear answer, we still need to optimize HW design and conduct much more compatibility test.
Scenario 2: with “Brain-warp”
The refresh rate is important to VR experience and it is challenging to system architecture. That's why Pimax brings out Brain-warp to our users. The technology will definitely double the refresh rate and reduce MTP.
All games can run 120Hz-180Hz as long as your GPU support that. You can choose to enable or disable the Brain-warp function after the performance test when you get the HMD.
If you enable brain warp feature, you don’t need care about the 5Hz or 8Hz drop of the refresh rate.
MTP = senor response time+ GPU rendering time + 1/refresh rate + display switch time
The refresh rate only one of the many factors that influence the MTP. There’re many other solutions to bring out good MTP performance. Including ATW/ASW/BrainWarp/.....
We will update the latest risks analysis of the whole project in two days. This will allow our backers do their own assessment again and have a final chance to make the decision before the Kickstarter campaign ends.
The Pimax Team