3D XPoint vs HBM - The 3D Memory War

[S0L0]

In short, 3D XPoint is essentially a DIMM slot SSD that performs at DDR4 speed. So fast that there is no need for actual RAM in a system and it doesn't wear out like flash ram.

some features:
same read write speeds
non-volatile (can store data when powered off)
cheaper than DRAM, more expensive than flash

The first generation of what Intel is branding "Optane" will be available via SATA, SATA Express, PCIe due in 2016. While the second generation will likely be launched with Cannonlake in 2017 for the Xeon.


HBM is not located where GDDR5 would be, it is actually located on the package where you would have a GPU/CPU but separated by an interposer. HBM can also be stacked vertically to allow for a theoretical 4 times the memory per chip. HBM is stacked by using tiny holes in the silicon called TSVs.

some features;
one gigabyte of HBM is smaller than one gigabyte of GDDR5
HBM is more power efficient allowing more power-hungry GPU/CPUs
HBM has a large bandwidth

The first generation of HBM is already available however its based on 28nm manufacturing process so it is not until the 2nd generation in 2016 we will see significant performance gains when the process switches to 14nm. Furthermore, it is likely AMD will use HBM with their APU line instead of DDR4.

 

[redzo]

They are designed for different use cases.

HBM is volatile and can't be used for external storage.

HBM exists and works in real products, 3D XPoint doesn't.

3D XPoint might turn up faster than NAND, but I've got a feeling that it is slower than DDR3/4 RAM. Companies always cherry pick positives about paper/future products.

 

[S0L0]

For now they are for diffreent use cases, but as the technology matures its likely that both will be used for both gpu & cpu.

 

[freeskier93]

3D XPoint doesn't even exist yet, and when it does it's only expected to come in SATA, SATA Express, and PCIe initially, which won't even put it in the same solar system as DDR3, let alone DDR4 and HBM. There's also a serious physical limitation to what you can push over motherboard traces (hence the brickwall with GDDR5), which will allow HBM to always be ahead because it can use a wider bus.

When HBM makes the leap from GPUs it will first dominate the mobile market, it's pretty much the ultimate package for laptops because of its lower power consumption, smaller overall package (no separate RAM chips), and will greatly boot integrated graphics performance. It will also work its way into desktop APUs since it will satisfy majority of the market needs, I'm not sure what we'll see in the HEDT/gaming market though.

 

[S0L0]

3D XPoint doesn't even exist yet, and when it does it's only expected to come in SATA, SATA Express, and PCIe initially, which won't even put it in the same solar system as DDR3, let alone DDR4 and HBM. There's also a serious physical limitation to what you can push over motherboard traces (hence the brickwall with GDDR5), which will allow HBM to always be ahead because it can use a wider bus.

When HBM makes the leap from GPUs it will first dominate the mobile market, it's pretty much the ultimate package for laptops because of its lower power consumption, smaller overall package (no separate RAM chips), and will greatly boot integrated graphics performance. It will also work its way into desktop APUs since it will satisfy majority of the market needs, I'm not sure what we'll see in the HEDT/gaming market though.

Intel is planning on implementing 3DXPoint differently from Micron who will likely have variants of it for PCIe 4.0 (due in 2017). However when PCIe 5.0 comes around it will likely have a completely different architecture from 4.0 (not going to be backwards compatible) and its likely we will see a convergence in memory and storage along with it. IMO by the time PCIe 5.0 comes around with Intel's 10nm tock computer architecture is going to be much different than it is in the current generation.

Also, 3DXPoint is also designed for mobile performance similar to HBM.


http://www.pcworld.com/article/2973549/storage/intels-crazy-fast-3d-xpoint-optane-memory-heads-for-ddr-slots-but-with-a-catch.html

http://www.kitguru.net/components/graphic-cards/anton-shilov/pci-express-4-0-with-16gts-data-rates-and-new-connector-to-be-finalized-by-2017/