Accessing RAM sometimes costs extra log(N)
1–5 of 5 posts
Re: Accessing RAM sometimes costs extra log(N)
#2In response to "The Myth of RAM" https://news.ycombinator.com/item?id=12383012
It so happens that a large part of my PhD was on this very subject. The result I've got N log(N), this is more visible when you get to larger RAM (I had 0,5 TB RAM at the time). We have an empirical result, a justification and a rigorous predictive model.
The reason has to do with hashing, but a different type: TLB.
Feel free to take a look at a free copy at http://arxiv.org/abs/1212.0703 where we establish the VAT cost model.
Re: Accessing RAM sometimes costs extra log(N)
#3[deleted]
Re: Accessing RAM sometimes costs extra log(N)
#4In response to "The Myth of RAM" https://news.ycombinator.com/item?id=12383012 It so happens that a large part of my PhD was on this very subject. The result I've got N log(N), this is more visible when you get to larger RAM (I had 0,5 TB RAM at the time). We have an empirical result, a justification and a rigorous predictive model. The reason has to do with hashing, but a different type: TLB. Feel free to take a loo…
Very interesting and informative. I would have expected a TLB to incur an additional cost beyond exhausting the cache hierarchy. But, I would have expected it to be a single additional cliff around a gig at most.
Shame there's no discussion here. I've x-posted to https://www.reddit.com/r/programming/comments/509qhd/randoml... Maybe that will drum up a bit more conversation.
Re: Accessing RAM sometimes costs extra log(N)
#5In response to "The Myth of RAM" https://news.ycombinator.com/item?id=12383012 It so happens that a large part of my PhD was on this very subject. The result I've got N log(N), this is more visible when you get to larger RAM (I had 0,5 TB RAM at the time). We have an empirical result, a justification and a rigorous predictive model. The reason has to do with hashing, but a different type: TLB. Feel free to take a loo…
Very interesting and informative. I would have expected a TLB to incur an additional cost beyond exhausting the cache hierarchy. But, I would have expected it to be a single additional cliff around a gig at most. Shame there's no discussion here. I've x-posted to https://www.reddit.com/r/programming/comments/509qhd/randoml... Maybe that will drum up a bit more conversation.
Thanks! Looks like it worked.