6 ms·

I can't wait for the DigitalOcean of RAM to appear. $5/mo VPS with 20GB RAMdisks, please.

rbanffy 13y ago
It could be very interesting for VMs with transient storage that need fast IO, but don't need to persist it on the machine itself. Thinking stream consolidation or analysis.
- mjolk 13y ago
  Session database in memory, mirrored to another host for redundancy, and only events that need to be stored written to "slow" SSDs when I/O bandwidth permits. I could bring my startup from 10 to 2 hosts and have better performance.
  - rbanffy 13y ago
    To be fair, that should be doable right now with DDR3. It's still much faster than an SSD.
    - deleted 13y ago
      [deleted]
    - mjolk 13y ago
      I suppose that's true, thanks for putting that in perspective. The real problem is that gobs of RAM isn't _cheap_. I wish that DDR4 would make DDR3 less expensive, but as manufacturers switch to making DDR4, I expect the price to rise. edit: Which is to say, I'd be happy if it became possible in the near future to get laptops with 48GB of of DD3 and junky Dell rackmounts with 256GB of RAM for today's prices of 16/64GB respectively.
      - dangrossman 13y ago
        > Which is to say, I'd be happy if it became possible in the near future to get laptops with 48GB of of DD3 The reason laptops still come with just 4GB of RAM has little to do with the cost of RAM. Each gig you add reduces battery life significantly.
        rbanffy 13y ago
        There are also diminishing returns for the average user. My mother would notice an SSD, but probably not another 4 gigabytes of RAM. Her computer almost never hits the swap partition.
        samstave 13y ago
        My last several laptops (System76) came with 16GB. Though I have never looked at the impact to battery... I run multiple VMs on my machine continuously (a win7 VM and a couple other linux VMs). The machine has dual SSDs and it's super freaking fast.
  - ricardobeat 13y ago
    That's quite common. Redis etc.
    - mjolk 13y ago
      redis is key/value, not meaning to be full normalized database
      - ricardobeat 13y ago
        Redis has complex data structures, not just key/val. You can also run a SQL db in-memory anyway.
        bjeanes 13y ago
        it's still k/v, it's just the values can be several different types of DS
nkurz 13y ago
Anandtech had a nice recent article on server memory types and costs: http://www.anandtech.com/show/7479/server-buying-decisions-memory http://www.anandtech.com/show/7479/server-buying-decisions-m... (https://news.ycombinator.com/item?id=7044992 https://news.ycombinator.com/item?id=7044992). It prompted me to go through and do some math. If you want to cram as much RAM in a server as practical, you'll currently be using 32GB LRDIMM's which currently cost ~$600 ($20/GB). Some dual-processor motherboards will take 24 of them (3 ranks * 4 channels * 2 processors) for a 768 GB total: http://www.supermicro.com/products/motherboard/xeon/c600/x9dr7-tf_.cfm http://www.supermicro.com/products/motherboard/xeon/c600/x9d... (The 1.5TB description for the board presumes the soon to be released 64GB LRDIMMS.) This would be $15000 for just the 768GB of RAM. Let's guess another $5K for the rest, so $20K for the machine. At 20GB of dedicated RAM per VPS, you can fit ~40 of them on the machine. $20K / 40 = $500. Since this ignores power and connectivity, I think you'll be waiting a while for a $5 month plan. Although perhaps you could overprovision and swap out a lot? Viewed alternatively, the sweet spot for selling RAM does not involve putting as much of it as you can in a single machine. You'd cut the cost of your RAM per GB a lot (down to about $10/GB) if you stuck with older lower density RAM put a bunch of low price blade servers in a single box.
- orik 13y ago
  Space in a datacenter gets prohibitively expensive fast. You'd need a real nifty virtualization platform to oversell RAM like we currently oversell bandwidth and cpu time. A high performance swap farm might be the way to go with things, but things break when everyone starts using huge pages.
  - wlesieutre 13y ago
    Right, the trouble with RAM is that if someone wants to keep a pile of data in memory, it has to stay loaded. I would hazard a guess that memory consumption on servers tends to be much less spiky than CPU is, and that's part of why a "DigitalOcean of RAM" is difficult to do.
- hrjet 13y ago
  Did you use bulk pricing in your calculations? Hosting services that buy in bulk would have a lot of bargaining power.

It could be very interesting for VMs with transient storage that need fast IO, but don't need to persist it on the machine itself. Thinking stream consolidation or analysis.

mjolk 13y ago
Session database in memory, mirrored to another host for redundancy, and only events that need to be stored written to "slow" SSDs when I/O bandwidth permits. I could bring my startup from 10 to 2 hosts and have better performance.
- rbanffy 13y ago
  To be fair, that should be doable right now with DDR3. It's still much faster than an SSD.
  - deleted 13y ago
    [deleted]
  - mjolk 13y ago
    I suppose that's true, thanks for putting that in perspective. The real problem is that gobs of RAM isn't _cheap_. I wish that DDR4 would make DDR3 less expensive, but as manufacturers switch to making DDR4, I expect the price to rise. edit: Which is to say, I'd be happy if it became possible in the near future to get laptops with 48GB of of DD3 and junky Dell rackmounts with 256GB of RAM for today's prices of 16/64GB respectively.
    - dangrossman 13y ago
      > Which is to say, I'd be happy if it became possible in the near future to get laptops with 48GB of of DD3 The reason laptops still come with just 4GB of RAM has little to do with the cost of RAM. Each gig you add reduces battery life significantly.
      - rbanffy 13y ago
        There are also diminishing returns for the average user. My mother would notice an SSD, but probably not another 4 gigabytes of RAM. Her computer almost never hits the swap partition.
      - samstave 13y ago
        My last several laptops (System76) came with 16GB. Though I have never looked at the impact to battery... I run multiple VMs on my machine continuously (a win7 VM and a couple other linux VMs). The machine has dual SSDs and it's super freaking fast.
- ricardobeat 13y ago
  That's quite common. Redis etc.
  - mjolk 13y ago
    redis is key/value, not meaning to be full normalized database
    - ricardobeat 13y ago
      Redis has complex data structures, not just key/val. You can also run a SQL db in-memory anyway.
      - bjeanes 13y ago
        it's still k/v, it's just the values can be several different types of DS

nkurz 13y ago

Anandtech had a nice recent article on server memory types and costs: http://www.anandtech.com/show/7479/server-buying-decisions-memory http://www.anandtech.com/show/7479/server-buying-decisions-m... (https://news.ycombinator.com/item?id=7044992 https://news.ycombinator.com/item?id=7044992). It prompted me to go through and do some math. If you want to cram as much RAM in a server as practical, you'll currently be using 32GB LRDIMM's which currently cost ~$600 ($20/GB). Some dual-processor motherboards will take 24 of them (3 ranks * 4 channels * 2 processors) for a 768 GB total: http://www.supermicro.com/products/motherboard/xeon/c600/x9dr7-tf_.cfm http://www.supermicro.com/products/motherboard/xeon/c600/x9d... (The 1.5TB description for the board presumes the soon to be released 64GB LRDIMMS.) This would be $15000 for just the 768GB of RAM. Let's guess another $5K for the rest, so $20K for the machine. At 20GB of dedicated RAM per VPS, you can fit ~40 of them on the machine. $20K / 40 = $500. Since this ignores power and connectivity, I think you'll be waiting a while for a $5 month plan. Although perhaps you could overprovision and swap out a lot? Viewed alternatively, the sweet spot for selling RAM does not involve putting as much of it as you can in a single machine. You'd cut the cost of your RAM per GB a lot (down to about $10/GB) if you stuck with older lower density RAM put a bunch of low price blade servers in a single box.

orik 13y ago
Space in a datacenter gets prohibitively expensive fast. You'd need a real nifty virtualization platform to oversell RAM like we currently oversell bandwidth and cpu time. A high performance swap farm might be the way to go with things, but things break when everyone starts using huge pages.
- wlesieutre 13y ago
  Right, the trouble with RAM is that if someone wants to keep a pile of data in memory, it has to stay loaded. I would hazard a guess that memory consumption on servers tends to be much less spiky than CPU is, and that's part of why a "DigitalOcean of RAM" is difficult to do.
hrjet 13y ago
Did you use bulk pricing in your calculations? Hosting services that buy in bulk would have a lot of bargaining power.