Video recording issues

[insider]

I recently tried recording my game video and ran into a issue I was unable to comprehend.
My Gaming Rig consists of an i7 4770K @ 3.5GHz, 8GB RAM, Motherboard supports data transfer speed of 6GBPS and all hard drives are Seagate 6GBPS drives with 6GBPS cables ofcourse.
My GPU is a Nvidia GTX760 with 2GB VRAM which is a pretty decent high end card.

Now to the issue. I mostly always use FRAPS for recording videos for my games and when I started recording the video I noticed a frame drop of almost 50%, I had VSYNC enabled and it was giving me 30FPS.
Now the interesting part is the frame drop only comes when I enable the default Ogre HDR Lighting compositor for my game, with HDR off I can record pretty well at a sufficient 60FPS.
I also purchased Mirillis Action to record the videos but disappointingly it gave the same FPS as FRAPS.

Now why do the post processing effects have such a great impact on recording videos, well I don't know.
I had a similar issue with my previous game, that one didn't have HDR Lighting feature but after a little hunting I found that Ogre shadows were causing the frame drop, hence I had to record videos with shadowing disabled

Now my PC as mentioned above has a pretty decent config and all the videos were being recorded on a dedicated 6GBPS internal hard drive and not the primary hard drive and I have checked all other issues such as Antivirus,Anti-Malware etc and they are not the issue.

So do I have to get another GPU and go SLI just to record video.
BTW I was using Ogre 1.8.1 if that helps.

[dbtx]

I have only limited (and dated) experience with capturing 3D (used FRAPS kind of a long time ago, before Youtube had HD I think) but I would definitely get a HDMI capture card rather than anything else, especially one that compresses with a variety of codecs in a dedicated onboard chip (intended for streaming games). The capture card looks to your system just like a monitor or TV that advertises some supported resolutions, so everything in 3D land is the same as when it's not being recorded: fast, minus the load of getting a stream over another PCI-e link into the disk(s). Or use another (possibly older) computer to hold the card & destination disk, and you're cruising.

[insider]

Well a HDMI capture card sounds like an interesting approach, will check it out
There are none available in my local IT shops so guess I ll have to import it and that would cause a 2 week delay, Argh !!