How to determine failing component

[megamanx321]

Hi all. I have a situation I was hoping some techie whiz could help me diagnose the problem. In the last year or two, my computer has been "pausing" when starting up. What happens is, either in the BIOS startup where it scans the SATA bus for drives, it will pause with the hard drive light solid, but no disk activity (e.g. spinning up, sector scanning) for a good 1-5 minutes. It pauses on any of the connected disks, including the SATA DVD-RW drive. The same happens when the bootup reaches windows screen. It will pause at the windows progress bar for 1-5 minutes, then everything is fine. If I hibernate, it will pause after it's restored and I have logged in. I've also had it completely lock up during gaming, backups to external USB drive using Acronis True Image, and had performance issues copying files from drive to drive (e.g. copying a 200GB backup file from one disk to another took over 19 hours, when the min read/write rate was 80MB/sec using HD Tune for both drives).

I've replaced both hard drives, removed the DVD-RW drive, and I last month had both memory chips replaced due to ongoing lockups and a scan with MemTest. I disabled the JMicron controller (eSATA and RAID functions which I don't use) thinking that was the problem. I flashed the BIOS with the latest version (AMI v1305 6/19/09). I'm leaning toward the either SATA controller on the motherboard going bad or the north bridge chipset. Oh and the motherboard is an ASUS P5K-E Wifi. I guess my question is more like:

What avenues of diagnostics are there to troubleshoot motherboard components?

Anyone have any ideas that might help? I searched the forums a bit and couldn't find anything that helped. Thanks in advance for reading/replying.

 

[casualbuilder]

Well, heres how i look at it...everything that was hooked up to the sata ports were "acting funny". You replaced them. They are still "acting funny". This tells me you either have bad SATA cables, or SATA ports.