4 ms·
How long until they just use dimm slots?
by ck2 12y ago
How long until they just use dimm slots?
- jotux 12y agoSATA DIMM slots are already available: http://www.vikingtechnology.com/satadimm-ssd http://www.vikingtechnology.com/satadimm-ssd
- zxexz 12y agoThat only uses the DIMM slot for power - it still uses a SATA connection. This definitely has its uses, though.
- conjecTech 12y agohttp://www.sandisk.com/enterprise/ulltradimm-ssd/ http://www.sandisk.com/enterprise/ulltradimm-ssd/ I think this one meets his description and makes actual use of the DIMM for memory transfer, though I've done relatively little research on it.
- wmf 12y agoHopefully never. Flash's characteristics are so different from DRAM that flash DIMMs just confuse people. But there is http://www.sandisk.com/enterprise/ulltradimm-ssd/ http://www.sandisk.com/enterprise/ulltradimm-ssd/
- pslam 12y agoYou can use the DIMM slot for the DDR bus interface, but not used in the traditional way DRAM would be. The DDR interface is extremely fast, and can be purposed for uses other than the standard row/column/select/precharge etc commands. You would likely need chipset support for it to be used in this fashion, though.
- wmf 12y agoThat's what flash DIMMs do. The problem is that if you stick something in a DIMM slot people expect it to behave like RAM, not like an I/O device.
- xanderstrike 12y agoI don't think the kind of person who buys a DIMM SSD is the type of person who is confused by that sort of thing. To a non-technical person, mSATA, DIMM, and PCIE SSDs all look the same. These products aren't for them.
- Someone1234 12y agoAgreed. It would be nice to see a set of slots for both RAM or an SSD. So your laptop may have four slots total, and you can mix and match RAM or drives as you see fit. The technology to do this is already commercially available in servers. Just need it to come to laptops or PCs.
- jader201 12y agoAt some point, I hope to see the lines between RAM and SSDs dissolve, such that the OS can just use a portion of the SSD for RAM.
- Someone1234 12y agoUhh, unless SSD technology changes significantly that line is a long long way off. SSDs are orders of magnitude slower than RAM. For example assuming a 2 GB/s speed is legitimate, RAM is over 22 GB/s. Plus RAM can be written and re-written without any wear, whereas SSDs have a max-write limit.
- ch 12y agoRight. Plus when you power off RAM ... Oops!
- pstuart 12y agoI think it's supposed to happen with these: http://en.wikipedia.org/wiki/Memristor http://en.wikipedia.org/wiki/Memristor
- Tloewald 12y agoHP is working on a new architecture based on computers with just a buttload of persistent RAM, but so far it's vaporware.
- walterbell 12y agoSupposedly they will never sell this computer, only renting access as a "fast cloud".
- jjoonathan 12y agoUgh. Well, I suppose it might be OK as long as it doesn't inherit anything about the DRAM hardware interface. Seriously, if you haven't seen how it works (test: are the timings tCAS, tRCD, tRP, tRAS familiar?) you are dramatically underestimating how ugly and restrictive the interface is. It's completely inappropriate for anything but DRAM and probably inappropriate for modern DRAM too. If not, it's probably because backwards compatibility with the interface has constricted DRAM design. Speaking of which, I'd love to read a modern analysis of chip-to-chip serial vs parallel if anyone has one handy.
- sliverstorm 12y agoIt may happen, but not without potential pitfalls. For example, modern CPU's cannot actually address the full 64-bit address range of memory, and if your drive is a DIMM device it is necessarily memory-mapped. CPU's can address a few tens or hundreds of TB. While few computers have that much disk, we aren't far off. http://en.wikipedia.org/wiki/X86-64#Canonical_form_addresses http://en.wikipedia.org/wiki/X86-64#Canonical_form_addresses
- jschwartzi 12y agoThere's nothing in that article that says you can't write a driver which utilizes certain addresses as registers and other address ranges as visible sections of a mass storage device, for example. That's just one hack workaround I can think of that would allow you to put flash into a DIMM. You could combine that with DMA to read data out of your flash DIMM and into your RAM DIMM. At that point, reading data would be a matter of setting up your paging registers and then queuing a DMA operation to copy data out of the exposed segment of your mass storage device and into RAM. Your flash DIMM would then be just another memory mapped hardware device.
- sliverstorm 12y agoHmm, good point. Looks like I was overthinking things.