I have never bothered trying the “small” mode as I thought it would offset the advantage of Pimax. Recently I tried the small mode to see how many FPS it could gain, and I found its usefulness is beyond FPS! For me the best gain is the diminishing of binocular overlapping which bothered all the time, and BO is now almost unnoticeable! And the FOV is not confining at all, still much bigger than Odyssey and Vive OG, not to mention CV1. I’d like to recommend this mode to you in different games, especially flight simulation. FPS in a very demanding scene in XP11 increased from 27 to 32.
13 Likes
Yes this mode is very good if we not need the big fov such as wave shooting game or some animation.
I use small fov + 500% super sampling and very impressive although I use gtx 1070, better gpu can make more performance.
I feel small fov mode has more clarity and beautiful image than normal fov. If you familiar with this fov, you will be okay with the next generation headset which has fov around 135-140 with more better panel and resolution.
6 Likes
So small FOV will still be more clearer and sharper than normal FOV even if you increase the normal FOV SS by a lot…?
1 Like
I think so, but not sure about bottle neck of my gpu, but I feel that small fov is sharper.
2 Likes
While it may not give a full proper result taking all factors into consideration there is a Bottleneck calculator that can give an idea of how much your cpu is possibly holding back your GPU.
In Steamvr settings Video click manual override to see what steam is setting base GPU utilization/SS.
On my i5-6500 with pitool at 1.0 it said 16%. After upgrading to ryzen 2700x it rouse to around 40% on my 1080ti.
2 Likes
Does the small FOV provide a performance advantage? I read that the FPS did not rise at all compared to the normal fov.
1 Like
20202020202020
3 Likes
Yes, but I’d look at it from another perspective. For a given CPU & GPU, you can have higher super-sampling, for a target framerate.
So, a smaller FOV can yield a higher FPS or allow you to have a higher quality image (at the same FPS).
3 Likes
I mean that! The FPS at the same settings, even with a smaller FOV are not higher than normal FOV ! Is that right or wrong ? I just read that!
Sorry, read over.
1 Like
The FPS at the same settings would typically be higher in small FOV. Depending on a PC’s bottlenecks, the FPS might not change.
An example of that is that for a typical scene in Elite Dangerous, I can lower the graphics settings (including lower res) and the FPS would almost never exceed 120 FPS (unless I really cranked the quality down). And no, that wasn’t the max refresh of the monitor; that is 60 Hz. Also, if I was in deep (empty) space, the framerate could jump to 180 or even 240 FPS. As an odd note, the framerate was often a little slower at a lower res. That seems counter-intuitive, but it’s probably due to memory access at suboptimal clock rate synchronization (between GPU and RAM).
3 Likes
So happy to hear you say this Can you pump supersampling higher on this mode as I initially suggested would be possible?
2 Likes
So happy to hear this. I was the 1st person to suggest variable FOV, and everyone thought it was a crazy idea until the idea picked up steam. Thank god it works, makes me happy. 
6 Likes
Yes, generally speaking, you should be able to increase the SS and maybe even the FPS (carefully balancing the 2 against each other) when using small FOV, compared to “normal” FOV.
2 Likes
Wowsers.
Which game may I ask?
2 Likes
Battlezone and a lot of game, only issue is wobble in some game.
I like the Serious Sam 3 most, but it look this game not use super sampling (after test again, it use sampling, may I confuse with doom BFE). But I can see different in Serious Sam the last hope, small fov look better. You can compare from large to small. It is about distance of enemy too.
1 Like
Why does BO bother you? Isn’t it something absolutely natural? We have this overlap all the time in your normal vision.
BO results in light black line in the FOV which is really annoying for me.
@neal_white_iii Do you know it or do you only suspect it? 2 german vr-forum members I know, say there is no change to the FPS despite the change in the FOV. No matter if big or small FOV ! Tested wtih PCARS 2 and Skyrim
I’m speaking in terms of the underlying math. In practice, there are real-world effects, as I mentioned above: https://community.openmr.ai/t/small-fov-is-surprisingly-good/13353/10?u=neal_white_iii
As to why there might be no FPS change, there are several possibilities: The most likely is that they were CPU limited. It’s also possible they didn’t “really” have the settings that they thought they were using. Sometimes, PiTool needs to be restarted and occasional, people have said that they needed to reboot their PC for the changes to take effect.
I can’t answer from personal experience, since I’m still waiting on my 8K to arrive.
3 Likes
I know what you mean and i share your opinion ! BUT …
It seems that the pp-function reacts slightly differently to this change and especially in the context of the large FOV! Both testers have always restarted SteamVR and PiTool.I will do my own tests next week and report.
I think the problem is the software, not the users 
btw : One of these testers uses an I9-9900k