Update as of 4/5/06:
I think I fixed the problem. I found out that I have a bad pair of memory sticks, Crucial 512MB PC3200 Ballistix. I went ahead and swapped them out for my working pair that I had in my work box and all is well. So far no more intermittent speed drops. It seems like it has all cleared up. I also started to experience download corruption. At the time I had already read about nVidia’s NIC causing corruption but come to find out, using both NICs caused the corruption. Sure enough, I decided to run Memtest86 from www.memtest.org and I did indeed have bad memory.
My memory is rated at like 2-2-2-8 @ 1T. I could NEVER run it that tight but with my new memory from my work machine, those timings are actually doable. I tried 2-2-2-7 but after running Prime95 for six hours it failed with one error. I’m going to have to change it back to 2-2-2-8 and see if it will pass Prime testing.
A few months ago I signed up for Giganews and Newzbin for Usenet service. Times got a little rough and I had to cancel my subscription to Giganews. During that time, I was able to get 590KBps consistently and the speed would never drop below 500KBps. I re-signed up again this past Saturday. I noticed that my speed would go up to 590KBps and then it would go down to 200KBps and then go back up. This would randomly happen every so many minutes. I ran trace routes, pings, all that good networking stuff to try and figure out where the bottle neck was, me or my ISP. I came to the conclusion that it was with my ISP after being shatted on by Giganews’ support. All they kept saying was, there is latency from this hop to this hop which means it’s your ISP, nothing we can do. Anyway, I go in to work today and try the connection from there. I’m live about a mile away from where I work. I go in, start the machine up, start testing and the download speed is consistently 590KBps or slightly below, it does indeed flucuate. It never once dropped below 500KBps which amazed me. I started to think maybe it was a software configuration with my box at home. I tried uninstalling a bunch of programs to no avail. I finally decided to change my NIC cards. I have an ASUS A8N-SLI Deluxe motherboard which has two onboard NICs. One is the nVidia based NIC and the other is a Marvel Yukon based NIC. Sure enough, I change NICs, reset my cable modem and my speeds are consistent with my work box. Boy am I glad this worked itself out the way it did. I was getting very upset knowing for damn sure my ISP wasn’t going to give two shits if my speeds weren’t up to par. Anyway, if you experience terrible latency while downloading things, try changing your NIC and see if that helps.