Does anyone happen to know what this setting does in SkyrimPrefs.ini? A few people on a different forum are doing an investigation on the game's performance, and I found that bFloatPointRenderTarget made my GPU usage skyrocket when set to 1. Looking up yielded only general information pertaining to floating point rendering relating to High Dynamic Range rendering, but I couldn't find any information specific to this setting.

Did it increase performance when set to 1?

It did not, but it definitely put more load on the GPU. I finally started capping GPU usage all over, and it would lower framerate.

The game's probably implementing its HDR by using a render target with 16-bit integer color components like Half-Life 2 does.

The bFloatPointRenderTarget option probably just makes it use a higher-precision one with floating point components. Of course, with all the content tuned to work with the integer-based RT it just makes the GPU work harder with no benefit.

Here is some info on floating point target:

http://www.tweakguides.com/UT3_8.html

Now, the game engine might ignore this command regardless if it's on/off, since HDR seems to be always enabled with AA on, and I haven't found a way to turn it off and use Bloom instead, or don't use anything at all. It's a real pain with Skyrim - I used to like the Oblivion way of turning it on/off, sometimes it was just too much and overused, same in Skyrim.

I would consider things very carefully before trying to apply any knowledge from Unreal Engine 3 here.

UE3 almost certainly uses a very different RT and shading setup, and the people mindlessly copypasting each other's Skyrim .ini "fixes" are making enough of a mess already; we don't need people trying to copypaste ideas from different game engines

Maybe it has something to do w/ shadows cause I've only seen some shadow tweaks enable this variable. Like this popular one: http://www.skyrimnexus.com/downloads/file.php?id=283

I've tested it and noticed no difference in shadow rendering, all it did was lower FPS.

Thanks for all the replies. I was just curious as to what could be causing all the load; our test shot was on the level part of the steps leading to Dragonsreach, facing towards the tree. My usage went up about 25% simply by turning on the setting; the only difference I saw in the screenshots was that some gravel and a couple bushes were more shadowed. I guessed that the setting was either an experimental or poorly implemented lighting/shadowing setting; if you do saveini from the command line ingame, it also populates the ini files with an HDR section, so it's definitely different.

Don't enable this... all it does is increase the precision level of floating point rendering for HDR and other shader (pixel/vertex) rendering targets.

Essentially it's "supposed" to increase the level of quality, less dithering and more precise/accurate, high color/effect range. Due to the way the game is made and how the engine functions, this setting is more of a "lets put it in there as an afterthought and not optimise it at all".

The GPU workload will increase and MOST people will see a MASSIVE drop in performance. I know i do.... Least on midrange-highend cards will see pretty significant drop if your already riding the 45-60fps range... lower cards will become totally slideshow

From my testing of the fuction... it didn't appear to have any effect at all, using a per bit comparison of images taken with it enabled and disabled, there was essentially ZERO change...... and i'm one that noticed even minimal change, like FSAA or whatever... nope.. this made no decernable change in all my comparison...

At this point in time, enabling it (setting it to 1) will only give you a drop in FPS.... nothing more....

That is good to know, I was wondering what that was as well

Well, at least we have a straight answer; I guess I was on the right track with my thinking.

Wow I have this set to 1 for some reason.. based on a tweak guide somewhere on the nexus sites. I'll definitely be turning this off tonight and seeing hopefully some fps gains.

Yes, it was possibly from the shadow tweak guide. Honestly, I decided to ditch it as it was actually increasing GPU usage and bogging down performance.

Yup. I use this one: http://skyrimnexus.com/downloads/file.php?id=283

which works well to clean up the jaggie shadows but has it set to 1 as part of the ini changes.

Hmmm...

I wonder if I should follow the guide again but skip the lines I know are unnecessary

It seems that bFloatPointRenderTarget will reduce outline on objects that are rendered over shadows when anti aliasing is being used.

I toggled it on and off today. Definitely higher gpu usage but no discernable improvement. I'll check again for that aura thing tomorrow.

Switching the option to zero improves framerates for my rig in sig by a nice 5 fps.. (which is a nice gain when i'm already running on the edge on my low end specced rig)

No discernable image changes noted....

Would recommend the change for anyone who hurting for extra performance...