HBM2 is updated – enables graphics cards up to 1.64 TB / s in bandwidth

Sky-high performance and energy efficiency were on the menu when the High-Bandwidth Memory (HBM) technology was first launched. However, low volumes and high costs have led to limited impact on the market as a whole. Instead, technology has found a niche in high-performance circuits for, among other things, data centers.

Towards the end of 2019, Samsung announced that a refined variant of the sequel HBM2 was on its way into production. The standardization body JEDEC is now officially launching an update of the HBM2 specification, where the previous extension “E” has been deleted at the end.

New is that JEDEC officially adds two more speeds of 2.8 and 3.2 Gbps per pin (3,200 MHz effective clock frequency), up from the previous ceiling of 2.4 Gbps. This means that a single HBM2 capsule can deliver a bandwidth of 410 GB / s over a 1,024-bit memory bus, which is an increase of 33 percent from before. This with a maintained voltage of 1.2 V and thus similar power consumption.

Otherwise, the specification for HBM2 is left untouched and each capsule can continue to house up to 12 stacked circuits of 2 GB (16 Gb) each. A single HBM2 capsule can thus have a capacity of up to 24 GB. This means that, for example, a graphics circuit with four HBM2 capsules can now be equipped with up to 96 GB together with a bandwidth of a staggering 1.64 TB / s.

The speeds can be compared to AMD’s Radeon VII, which with four HBM2 capsules delivers a capacity of 16 GB with 1 TB / s bandwidth over a 4,096-bit memory bus. It can also be compared to Nvidia’s flagship Geforce RTX 2080 Ti, whose 352-bit memory bus with 11 GB GDDR6 at 14 Gbps (14,000 MHz) has a bandwidth of 616 GB / s.

At the same time as JEDEC is updating the HBM2 specification, Samsung announces that they are ready to deliver their solution called “Flashbolt”. Up to 16 GB is delivered here in a capsule with a bandwidth of 3.2 Gbps per pin or 410 GB / s per capsule. However, the South Korean electronics giant does not stop there.

Samsung also says that they can push up Flashbolt as high as 4.2 Gbps per pin in an overclocked mode, which gives a bandwidth of as much as 538 GB / s per capsule or just over 2 TB / s with four pieces. Whether this will be something that is used in practice remains to be seen, as such speeds also presuppose that the memory controllers of the circuits can operate at such speeds. Samsung Flashbolt goes into production during the first half of the year.

When the first circuits with updated HBM2 will find out and whether it will be in any consumer products remains to be seen.

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