How odd is this one.

One of the hard disks in my main PC died, so I decided to move all my stuff onto a spare 500GB SATA drive (my PC is IDE-based) I had lying around.

I plugged my SATA drive into another PC using an IDE/SATA USB adapter off eBay - you can plug either SATA or IDE into one end, and the other end is USB. I noticed when I had it connected, the other PC's network speed would be drastically reduced - internet speed was about 2kb/s, and when I ran my ISP's speed tester, it had my upstream/downstream speeds as about 0.06kbps. I ran a few tests over a series of nights and had the same result.

I discovered that when I had the disk unplugged, internet speeds went back to normal (something like 7.6mbps). Literally, I would do a speed test, get 0.06kbps, then unplug the hdd, run another speed test and get 7.6mbps.


I've now moved all my stuff over to the new drive, and using an IDE/SATA converter board connected to the motherboard of my main PC (it just sits in the IDE slot, and presents a SATA port on the other end) have connected my 500GB SATA drive.

I just ran a internet speed test from my main PC and it comes back as having a max of 1750kbps - about 220kb/s. My other PC is sat right next to it, connected to the same router and if I run a test on that a minute later, I get 7.6mbps.

Why/how is the new hard disk affecting my internet speed? The PC isn't maxing out on I/O or CPU or anything, it just seems that the network speed is much slower.