4 ms·

Is that really a possibility? I assumed the 6 Gb/sec (as Wikipedia claims) for SATA 3 would be sufficient bandwidth for any drive storage. I'll admit, I've not

Is that really a possibility? I assumed the 6 Gb/sec (as Wikipedia claims) for SATA 3 would be sufficient bandwidth for any drive storage. I'll admit, I've not followed this sort of hardware closely but my understanding was that SATA is set on its own track, apart from the other buses like PCI and USB.

jws 15y ago
DDR-3's bandwidth is about 20 times SATA-3's. I'm sure people will make SATA SSD's. There is an architecture revolution to be had, but it isn't as easy carving off a high speed bus from the CPU and turning your database speed up to a factor of 20. If the write lifetime is a million writes, at 10ns/write you can burn that up in a millisecond.[1] Maybe you trust your server hardware to last for three years.[2] You get about 38 writes per hour. I hope you aren't syncing a critical chunk of data once a minute. So you have an insanely fast, nonvolatile store, but you can't just write to it willy-nilly. Let the engineering begin! (I'm sure it has for some people.) -- [1] Malware can be expensive in a hurry. A couple quick loops and you can ruin 1000 blocks/second. [2] If you have less than a few dozen servers you end up playing quality roulette. You have no idea which models from which vendors are going to hold up, so you make a guess based on reputation and price. Sometimes you are right, sometimes you are wrong. Sometimes you have a 50% mortality in 6 months. When you get a model that works well, by the time you know it lasts, you can't buy it any more. My strategy was always to buy a batch, run them in non-critical positions for 6 months to screen for early failures, if they were good, move the critical functions to them, but then get off of them before the age related failures begin. Three years was about my limit.
sciurus 15y ago
You can get a PCIe solid state drive today with speeds higher than SATA3 can provide. Here's one with a read speed of 12.5 Gbit/s. http://www.ocztechnology.com/ocz-revodrive-3-x2-max-iops-pci-express-ssd.html http://www.ocztechnology.com/ocz-revodrive-3-x2-max-iops-pci... Device controllers used to be divided between a northbridge (memory, video) and southbridge (pcie, sata, usb, etc), but in the latest generation northbridge components are integrated into the CPU. http://en.wikipedia.org/wiki/Northbridge_%28computing%29 http://en.wikipedia.org/wiki/Northbridge_%28computing%29 http://en.wikipedia.org/wiki/Southbridge_%28computing%29 http://en.wikipedia.org/wiki/Southbridge_%28computing%29 http://en.wikipedia.org/wiki/Intel_5_Series http://en.wikipedia.org/wiki/Intel_5_Series

jws 15y ago

DDR-3's bandwidth is about 20 times SATA-3's. I'm sure people will make SATA SSD's. There is an architecture revolution to be had, but it isn't as easy carving off a high speed bus from the CPU and turning your database speed up to a factor of 20. If the write lifetime is a million writes, at 10ns/write you can burn that up in a millisecond.[1] Maybe you trust your server hardware to last for three years.[2] You get about 38 writes per hour. I hope you aren't syncing a critical chunk of data once a minute. So you have an insanely fast, nonvolatile store, but you can't just write to it willy-nilly. Let the engineering begin! (I'm sure it has for some people.) -- [1] Malware can be expensive in a hurry. A couple quick loops and you can ruin 1000 blocks/second. [2] If you have less than a few dozen servers you end up playing quality roulette. You have no idea which models from which vendors are going to hold up, so you make a guess based on reputation and price. Sometimes you are right, sometimes you are wrong. Sometimes you have a 50% mortality in 6 months. When you get a model that works well, by the time you know it lasts, you can't buy it any more. My strategy was always to buy a batch, run them in non-critical positions for 6 months to screen for early failures, if they were good, move the critical functions to them, but then get off of them before the age related failures begin. Three years was about my limit.

sciurus 15y ago

You can get a PCIe solid state drive today with speeds higher than SATA3 can provide. Here's one with a read speed of 12.5 Gbit/s. http://www.ocztechnology.com/ocz-revodrive-3-x2-max-iops-pci-express-ssd.html http://www.ocztechnology.com/ocz-revodrive-3-x2-max-iops-pci... Device controllers used to be divided between a northbridge (memory, video) and southbridge (pcie, sata, usb, etc), but in the latest generation northbridge components are integrated into the CPU. http://en.wikipedia.org/wiki/Northbridge_%28computing%29 http://en.wikipedia.org/wiki/Northbridge_%28computing%29 http://en.wikipedia.org/wiki/Southbridge_%28computing%29 http://en.wikipedia.org/wiki/Southbridge_%28computing%29 http://en.wikipedia.org/wiki/Intel_5_Series http://en.wikipedia.org/wiki/Intel_5_Series