4 ms·
If cas latency haven't changed for 20 years, and the memory wall in general being a huge pain, does anybody know why didn't some sort of 2.5D memory(even using
by petra 10y ago
If cas latency haven't changed for 20 years, and the memory wall in general being a huge pain, does anybody know why didn't some sort of 2.5D memory(even using low-resolution lithography and carriers cheaper than silicon), haven't entered the market ?
- Retric 10y agoHeat, RAM puts out a lot more than you might think. That said, for low power devices like cellphones you can use different packaging and cut latency. Also, AMD for example uses stacked ram (HBM), but that needs very special packaging and active cooling. http://www.amd.com/en-us/innovations/software-technologies/hbm http://www.amd.com/en-us/innovations/software-technologies/h... https://en.wikipedia.org/wiki/High_Bandwidth_Memory https://en.wikipedia.org/wiki/High_Bandwidth_Memory
- petra 10y agoIf heat is the problem, and since the memory wall is a 20-year problem, was there some new cooling tech ? or is it just standard industry inertia(and just being satisfied with half solutions) ?
- dom0 10y agoNo, it's a fundamental issue with the technology. Roughly, the ratio of power density to capacity-that-can-hold-information-for-a-refresh-interval stays more or less constant, independent of fab node. In fact, newer generations (DDR3, DDR4) have been pushing it here (cf. rowhammer). I doubt we will see a drastic improvement in DRAM latency unless the underlying process changes a lot (i.e. different physical storage mechanism or very different manufacturing).
- theandrewbailey 10y agoI think that's what HBM tries to do, with stacking memory dies on top of each other, along with locating them next to its associated processor.