Samsung says it has started making a new and faster form of DRAM.
The Korean colossus says the wheels are turning and pistons pumping at plants churning out High Bandwidth Memory (HBM2) DRAM.
HBM2 was only signed off as a standard on January 12th, when electronics industry standards group JEDEC (founded as the Joint Electron Device Engineering Council but now known as the Solid State Technology Association) published an update to the HBM spec.
The key new bits in HBM2 are a 1024-bit wide device interface divided into eight independent channels on each DRAM stack.
JEDEC says there's also “a new pseudo channel architecture to improve effective bandwidth, and clarifications and enhancements to the test features” plus “a new feature to alert controllers when DRAM temperatures have exceeded a level considered acceptable for reliable operation so that the controller can take appropriate steps to return the system to normal operation.”
Samsung says its DDR4 HBM2 DRAM “is created by stacking a buffer die at the bottom and four 8-gigabit core dies on top. These are then vertically interconnected by Through Silicon Via (TSV) holes and microbumps.”
TSV is a silicon-stacking technology that builds vertical connections within chips, to speed up internal comms to faster speeds than would be possible if signals were sent back out to wires. It's often mentioned during discussions of “3D memory” as it allows RAM to be stacked, rather than spread out.
More TSV connections therefore speed things up and boost density. Or as Samsung puts it: “A single 8Gb HBM2 die contains over 5,000 TSV holes, which is more than 36 times that of a 8Gb TSV DDR4 die, offering a dramatic improvement in data transmission performance compared to typical wire-bonding based packages.”
Long story short? This is the latest and greatest DRAM, will have twice the bandwidth of ye olde HBM1 memory and leaves the even more venerable GDDR5 and its measly 36GBps bandwidth floundering in the dust wondering what knocked it off its dinosaur and broke its stone underwear.
Which is just what you want if you run high-performance computers or graphics-intensive applications, the markets that are nearly always early adopters for technologies that offer a speed bump at the kind of premium prices that come with relatively low manufacturing volumes. It's also good new for graphics card manufacturers, because it will let them pack in more memory without bulking out their products to unfeasible sizes.
Samsung isn't saying when the 4GB packages will land but says it'll have an 8GB HBM2 package by year's end. ®