actually direct solder to the pin header would work out like a (40 wire) cable.
Where as if you want better than 33Mb you would want a 80 wire cable..
The xbox hardware is ATA-100..
the cable is ata-33... So yes lots of us upgrade the 40 wire cable to an 80 wire cable to utilize the extra speed..
With out saying its pixies and magic that does it all..
the basic of how it works (80 vs 40 wire) is that with a 40 wire all the ground gets fed back thropugh about 4 wires and causes feedback.. "crosstalk"
ata 80 wire cables sends the ground back through all the aditional 40 extra wires that were added, so you eliminate Lots of the feedback "crosstalk." and that in turn increases the max throughput of the system..
they had to change to 80 wires to get faster then 33MB's
(you may want to google for more information on how it works)
I will give a general every day eexample of the the diference..
(this is nopt really a quote its just breaking up the post for you)
person A and person B have the exact same system same hard disk same everything.. "this is assuming the ide hard disks are ata-100 or faster"
But person A has a 40 wire ribbon cable and Person B has an 80 wire cable..
they both Ftp the exact same copy of halo 2 from the same computer to there xboxes..
person A and person B both start the game at the exact same time.
Person B's game finishes loading 2-3 seconds before person A's game
this improvemnt came by removing the bottle neck caused by a 40 wire cable and replacing it with an 80 wire cable.
the diference would be more noticable with a larger load with the maximum possible improvemnt being 66% faster, although in reality we would most likley enjoy 40-50% faster load times.
i think that covers it all..
but yeah basics are..
if your soldering directly then you will "more than likley" be limited to 33Mb's so theres no point geting a faster cf card. (im not sure exactly how much of the corsstalk would be eliminated by having no wires for the crosstalk to be able to compromize the data traveling, and thats why i say more than likley.)
if you want to get the most out of your hardware you may want to think about making a custom 80 wire ata cable, (or atleast trimming down an existion one so it only has one connector.)
the xbox is ata 100, limited by the cheapo wire.