>> I don't see how on any recent hardware, random access to RAM is slower
>> than
>> sequential from disk. RAM access, random or not, is measured in
>> GB/sec...
>
> I don't think anybody's arguing that.
http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2795&p=5
These guys mention about 50 ns memory latency ; this would translate into
20 million memory "seeks" per second, which is in the same ballpark as the
numbers given by the article...
If you count 10GB/s bandwidth, 50 ns is the time to fetch 500 bytes.