after doing the pinmod on my xw4400 HP workstation to boost 1.8ghz E4300 to 2.4ghz, the default player handles the haali mkv full speed without stutters. no voltage changes necessary rock solid. I guess the extra cpu speed helped out whatever was holding up the system. This modification does not speed up the FSB/PCI at all so i guess thats a good sign of where you want to be at minimum for full 1920x1080P playback. Add other tasks on top of that (recording) and you might want to choose something more appropriate. The E2140(1mb L2) and E4300(2MB) are cheap and easy overclockers. 55 bucks for e4300's these days alot of people with elite cooling and voltage hacks have been able to see 3.2 to 3.6ghz out of these chips but i didn't want to go that hardcore with a OEM pre-built workstation that i got cheap
thankfully now i can enjoy my haali mkv 1080p videos and begin the transition from xbmc(xbox1) to media portal for good.
xw4400 smartbuy workstation (undisclosed price) running vista business
8600 GT OC ($66 after paypal/newegg description refund/MIR) @ stock speeds
CCCP codec pack with coreAVC 1.5 and purevideo HD (filmerit/DSF/graphedit to tweak merits)
Xplosion 7.1 (sondingo inferno works good too) $79 - upsamples everything to DD/DTS 5.1 and passes thru ac3/dts/dd streams
3 MCE remotes and IR receivers (using 1 but you had to buy 3 pack - oem).
2.5gb dual interleaved ($16 A/R 1GB DDR2-667 HP PROMO DIMMS *2), box came with 2 DDR2-667 256meggers.
2GB sandisk cruzer (got it free from someone) as readyboost. not sure if its helping or hurting.
will add all drives external USB or firewire to keep the unit cool and quiet. 500gb firewire/usb units are like $79-99 these days. stackable. I just playback so i'm not needing the fastest speed possible
I believe i could have gone cheaper but who knows what new formats will come out that might eat more cpu in the next few years..