Is there are conceivable reason why some of the websites I try to access go infernally slow while others dont?

[TRCDROM]

This could be for many reasons. Further diagnosis needs to be to identify the issues. Reasons could include:

1) Maybe at the moment you are looking to those sites your computer is slowing down for another reason (virus protection scan starting, etc...)

2)Maybe your ISP is slow at that moment for no specific reason (just busy)

3) Maybe your you/you ISP is slow to that site because of some misconfiguration somewhere on the Internet (e.g. bad routing tables somewhere, bad routers, etc...)

4) Maybe it is not on your end at all and the site your are visiting is very busy

5) Maybe it is not on your end at all and the something connected to the site your are visiting is misconfigured or broken (e.g. one server in a web farm is not working correctly and if you are lucky enough to be sent to that server you get poor or no performance while everyone else is getting good performance)

6) You ISP may be throttling your throughput to these sites (maybe to all sites)

7) One of a million other items

I would make use of tools like ping, tracert, nslookup, etc... to test connectivity, name reoslution, etc... to those specific websites as well as other sites you visit where the performance is good. I wold also make use of websites like DSLREPORTS.com to test the performance on your side