I suspect what you have done is to install an old 40 conducter ide cable.
When the bios sees that cable it slows the ide port speed to udma 2.
You should be able to verify this by looking around in the bios.
If the speed is set to udma 2 then what you need are some 80 conducter cables.
Get the round ones---their PRETTY.
I had to grab a IDE cable from an old computer i have,like very old,looks like it was from the very early 90's.The computer i put it in is a 2.2 ghz Amd Athlon XP,and i have a 80 gb hard drive with a 8 mb buffer on it.I am using the older ide cable for my hard drive,but my computer does not seem to run at it's full potential.Even my cd-rom which is a 52X only seems to go the speed of my 24X cd-rom.Should i get another IDE cable,i thought they all went the same speed or so?

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