RAMCloud puts everything in DRAM

Post by corysama » Thu, Oct 06, 2011, 2:40 AM UTC

dextorious wrote: post #31

fleitz wrote: post #17

"Imagine a world where data layout doesn’t matter, where apps are optimized for sub-millisecond storage, where 100 byte I/Os are faster and just as efficient as 8KB I/Os. The architectural implications are huge and would take a decade or more to get our heads around." Umm.. I've worked with in memory data structures (who hasn't?) and yeah, layout DOES matter. Especially if your data structure is larger than a cache l…

"Umm.. I've worked with in memory data structures (who hasn't?) and yeah, layout DOES matter. Especially if your data structure is larger than a cache line." That's only compared to the speeds gained by different memory layouts. But compared to hard/solid state disks (which is the whole point here) the difference is less than insignificant.

It just itches a nerve to hear "It's a 1000x faster already! Data layout doesn't matter!" when you are thinking back "Well, it's also 1000x more expensive and it could have been 50,000x faster if you had put a bit of thought into your data layout."

I'm a crusty old console game dev. The explanation I give the new kids is: "Remember the PlayStation2? It ran at 300MHz and had a memory latency of 50 cycles. But, the PS3 is faster, right? It runs at 3000MHz and has a memory latency of 500 cycles. You know what happens when you don't think about memory layout? The PS3 runs at the same speed as the PS2!"

Post by sshirokov » Fri, Oct 07, 2011, 8:22 PM UTC

jasonwatkinspdx wrote: post #25

jasonwatkinspdx wrote: post #24

Earlier quoted context omitted.

1.) Reading the position paper should help you with that. It cites some prior literature. In particular the DeWitt paper should be a good jumping off point on citeseer or the like. For that matter, reading DeWitt's papers should cover a great deal of academia's exploration of novel database architectures. 2.) It's a position paper. It's not attempting to assert a novel invention from day one, it's staking a claim abo…

Sorry if I seem cranky, but I'm damn tired of people doing drive by criticisms of "ALREADY BEEN DONE BRO" on hackernews, particularly when they clearly haven't even read the primary sources. Novelty or originality are not the only requirements for noteworthiness. A great deal gets done confirming prior experience or making relatively modest and obvious evolutionary extensions of previously well known work.

No worries. It was a query of clarification not trolling, thanks.

Re: RAMCloud puts everything in DRAM

Re: RAMCloud puts everything in DRAM