|Really interesting article on the different types of memory chips.|
HBM2 Vs. GDDR6: Tradeoffs In DRAM
Experts at the Table, part 1: Choices vary depending upon application, cost and the need for capacity and bandwidth, but the number of options is confusing.
June 13th, 2019 - By: Ed Sperling
Semiconductor Engineering sat down to talk about new DRAM options and considerations with Frank Ferro, senior director of product management at Rambus; Marc Greenberg, group director for product marketing at Cadence; Graham Allen, senior product marketing manager for DDR PHYs at Synopsys; and Tien Shiah, senior manager for memory marketing at Samsung Electronics. What follows are excerpts of that conversation.
SE: What are the big challenges in memory today?
L-R: Frank Ferro, Graham Allan, Tien Shiah, Marc Greenberg. Photo credit: Semiconductor Engineering/Susan Rambo
Ferro: The main ones are latency and bandwidth, and those haven’t changed very much. But the key difference now is that we’re seeing a swing back from where we had plenty of bandwidth and the compute was the bottleneck to where memory is the bottleneck again. That has given rise to a number of different technologies. HBM basically came out of nowhere a couple years ago, and now GDDR is showing up on everyone’s radar. To some extent we’re still at the mercy of the memory vendors because we’re building physical layers based on their specs and the JEDEC specs. But architecturally, we are looking at ways to innovate. That’s the next step.
Allan: Our customers are faced with a large array of choices, and if you fit into the category of someone who doesn’t need a vanilla interface and you have something that can be challenging or a relatively high-bandwidth requirement, you’re left with all these choices and you don’t know which one to go for. It’s a very difficult market to navigate when you’re not one of the major CPU vendors because you don’t get a lot of insight from the DRAM vendors. There are a lot of secrets in the memory market, such as how much does a DRAM cost. You can find out what DDR4 costs in very large volumes, but if you want to know what HBM or GDDR6 sell for, you can’t get that answer. And it changes every month, because DRAM prices fluctuate quite a bit. One of our main activities is walking customers through all of these different choices and what the tradeoffs are.
continues at semiengineering.com