Replace my GT 640 with an HD 6670 for HTPC

[bryan240g]

I have an HTPC in my living room. Here are the specs.

Asus F1A55-M LX Plus R2.0 mobo
AMD A8 3870k CPU
8gb of ddr3 ram
EVGA GT 640 2gb card which is gddr3

With the exception of the GPU, I got these parts new for a steal. The GPU I already had. I was not planning on an AMD CPU at the time of purchase and had not researched it. Now I have read that with an HD 6670 with 1gb of gddr5 I would be able to use dual graphics with the card and CPU integrated graphics.
The primary use of this HTPC is streaming bluray and DVD rips. I also do use it for ripping and encoding movies when not watching them.
My question is would I benefit much from swapping the GT 640 to say an Asus HD 6670 with the gddr5.
The only issues I have encountered with the system while streaming encoded bluray rips which I have in .mkv format. Is that when playing a movie in vlc player and fast forwarding, the picture goes pixelated, choppy and freezes for a second. Then plays perfect. That's it. All parts have latest drivers and firmware. The only other minor nag is that when I start the movie the screen goes black which is the integrated graphics switching over to the GPU.

The HTPC has a 60gb corsair SSD(the red ones) for the programs and OS. All the movies play from a 2tb hdd with 64mb cache and spin at 7200rpm.

Well what are y'all's thoughts?

 

[djangoringo]

For mkv playback i recommend using the MPC-HC+lavfilters+madvr or if you want really a pack the k-lite codec pack, vlc just sucks.
I don't think it is worth spending money on that card for htpc, the one you have will do just the same if not better cause of the cuda cores in lavfilters...or madvr.
And no point in the crossfire for that too.

 

[bryan240g]

Thanks for the reply. I have been using vlc for so long I just never bothered to switch. I will give MPC a try with the extras you mentioned and see how it goes. As far my question about GPU switching. I figured I would get those kind of replies. But for conversation sake thought what the hell? I'll ask the community.