Megui encoding times for 1080i material vs 720p..

[uncertainty]

I'm currently using megui to encode my ts collection and find with x.264 encoding, using the "slow profile", I get around 30+ fps for the 1st pass with 1280x720p material. However it seems I take a massive hit when trying to encode 1920x1080i material. First I know due to the resolution it should take longer but currently I get around 3-4fps for the first pass with 1080i. I use megui to analyze the 1080i material for the avisynth script and was wondering if anyone can comment on this script and let me know what if any I could do in order to speed it up but still keep quality.... thanks

My system
E6400 OC to 3.2mhz
2 gigs ram


DGDecode_mpeg2source("G:\Hd-mpeg\planet earth1-hd.d2v")
edeintted = AssumeTFF().SeparateFields().SelectEven().EEDI2(field=-1)
tdeintted = TDeint(edeint=edeintted,order=1)
tfm(order=1,clip2=tdeintted).tdecimate(hybrid=3)
#crop
BilinearResize(1280,720) # Bilinear (Soft)
#denoise

[Selur]

edeintted = AssumeTFF().SeparateFields().SelectEven().EEDI2(field=-1)
tdeintted = TDeint(edeint=edeintted,order=1)
tfm(order=1,clip2=tdeintted).tdecimate(hybrid=3)
If you want it faster don't always select the 1st deinterlacing method mentioned. It's a dropdown there should be other options. Yadif might also be worth a try.

Cu Selur