RAM Is the New Disk • Hacker News Board

Re: RAM Is the New Disk

#21

Post by adrianratnapala » Mon, Jul 31, 2017, 3:00 AM UTC

If a terabyte is a lot of data to you -- and it is for many, many things, then this post is right; you should buy as much RAM as you have data, and access it accordingly.

The commenters who are saying disk has a different price/performance trade-off that is still valuable are also right, but that applies to large data sets.

Re: RAM Is the New Disk

#22

Post by jsudhams » Mon, Jul 31, 2017, 3:01 AM UTC

Not sure i agree, on Server spec the ram cost 10% more than CPU like if CPU cost 2000 then ram cost would be like 2200. Also it is not scalable for amount of data and not sure if I agree on laptop as well , 8gb ddr3 is about $80 while I can get 128gb ssd or 1tb magnetic disk so really can't use memory instead of disk. Except in few cases

Re: RAM Is the New Disk

#23

Post by godelmachine » Mon, Jul 31, 2017, 3:24 AM UTC

This might be the single most important article I have read in the past one week, because Adrian Colyer is on vacation! May I add that even SAP HANA is designed for in memory computing? As far as disks are concerned, NVM should soon replace them.

Re: RAM Is the New Disk

#24

Post by vbezhenar » Mon, Jul 31, 2017, 3:59 AM UTC

May be with very high-end servers it is. But generally it's not. I can buy 4TB HDD For $200. I think, I'll have to add 2-3 zeros for 4TB RAM machine, and I'm not even saying only about RAM, I need some server motherboard, some server processor, while I can use 4TB RAM HDD with pretty much any computer. And SSD isn't going to be even with HDD in near future as well for $/Byte. So optimizing software for HDD won't go anywhere. But, of course, it's awesome to have some alternatives if you have money and need more performance.

Re: RAM Is the New Disk

#25

Post by WalterBright » Mon, Jul 31, 2017, 4:06 AM UTC

Extensive use of "RAM" disks was commonplace in the 1980s.

Re: RAM Is the New Disk

#26

Post by ajross » Mon, Jul 31, 2017, 4:11 AM UTC

toast0 wrote: post #14

I think the insight here may be that ram should be optimized for sequential access, just like the disks of old.

It is, that's what "fast page mode" was in the late 90's and what prefetch queueing is in DDR.

Re: RAM Is the New Disk

#27

Post by [deleted] » Mon, Jul 31, 2017, 4:33 AM UTC

sriram_iyengar wrote: post #13

Excellent insights. If cost is not a factor, how does improvements in SSD space stacks against RAM ? Thanks

[deleted]

Re: RAM Is the New Disk

#28

Post by arielweisberg » Mon, Jul 31, 2017, 4:33 AM UTC

nikhilgarg28 wrote: post #10

arielweisberg wrote: post #5

... I was the third engineer at VoltDB and spent six years making that bet. It's not a good bet. Maybe there are other factors, but if VoltDB could page out cold data to disk I think it would be at least 2x if not more successful. No one agreed with me so it never happened. I saw so many use cases go out the door because hey you know what? RAM is expensive and it's cheaper to page out cold data. The scale where that…

Curious - why did people not agree with you? Was it an ideological belief or were they betting on some assumptions that turned out to be incorrect?

Do I really know? I'm not sure. I have opinions, but for the most part I was kept in the dark. There was a roadmap handed to me and what was on it was already decided.

We did work on equally important things also, but we also split focus with IMO unimportant things.

A combination of me not having a seat at the table (literally was told this after a year or so) and IMO non-technical leadership driving focus by chasing what they thought were the important factors.

The company survives and does OK though.

Re: RAM Is the New Disk

#29

Post by zeusk » Mon, Jul 31, 2017, 4:40 AM UTC

vbezhenar wrote: post #24

May be with very high-end servers it is. But generally it's not. I can buy 4TB HDD For $200. I think, I'll have to add 2-3 zeros for 4TB RAM machine, and I'm not even saying only about RAM, I need some server motherboard, some server processor, while I can use 4TB RAM HDD with pretty much any computer. And SSD isn't going to be even with HDD in near future as well for $/Byte. So optimizing software for HDD won't go a…

NVMe drives which are approaching RAM speeds are a good compromise if RAM and server components are outside of your financial reach.

Re: RAM Is the New Disk

#30

Post by runeks » Mon, Jul 31, 2017, 4:44 AM UTC

tw04 wrote: post #11

The price of disk has dropped at nearly the same pace as ram. As has the cost of compute. At the same time data growth has increased faster than either has dropped... so I'm not really sure the price argument holds water. If I can buy ram at 1/100th the cost but I need to store 500x more data... that isn't a net win on cost. From ~$1000.00/gb to $0.03/gb http://www.mkomo.com/cost-per-gigabyte-update

It would be interesting to see that chart updated to 2017 data. It appears the downward slope becomes significantly less steep around 2009 (looks like the price dropped as much from 2006-2008 as it did in the five years 2009-2014), and I’d be interested in seeing how recent SSD prices affect this. As far as I can see, rotational HDD technology is at the end of its S-curve, whereas SSD technology is still relatively new.