That RAM is stacked

Subject: General Tech | November 28, 2013 - 01:48 PM |
Tagged: DRAM, HMC, hybrid memory cubes, micron, TSV

Hybrid Memory Cubes are DRAM stacked in layers with logic on the bottom layer to decide which memory layer to address commands to whic is being developed by a team that includes Altera, ARM, IBM, SK Hynix, Micron, Open-Silicon, Samsung and Xilinix.  This is intended to give DRAM enhanced parallelization which will help it keep up with today's multi-cored processors.  Micron's example which the Register takes a look at here claims up to 10 GB/sec (80 Gb/sec) of bandwidth from each of the 16 vaults present on the chip, a vault being an area of memory on a layer.  That compares favourably to the maximum theoretical JEDEC speed of DDR3-1333 which is just a hair over 10GB/s.  Read more here.

View Full Size

"Dratted multi-core CPUs. DRAM is running into a bandwidth problem. More powerful CPUs has meant that more cores are trying to access a server’s memory and the bandwidth is running out.

One solution is to stack DRAM in layers above a logic base layer and increase access speed to the resulting hybrid memory cubes (HMC), and Micron has done just that."

Here is some more Tech News from around the web:

Tech Talk

Source: The Register
November 29, 2013 | 06:46 AM - Posted by Anonymous (not verified)

While I get that the stacking improves density and increases parallelisation , how is this stack connected to the CPU ?

My understanding is that memory BW is limited by the interface between memory controller on die and the memory module via the motherboard - i.e JEDEC DDR spec . How does this solution overcome this ?

Is the memory stack going to be soldered onto the processor die or PCB ? or is it slot module like present ?

Some clarification please . THNX

November 29, 2013 | 02:21 PM - Posted by MrBlack

Stacked - but it's all silicon

Post new comment

The content of this field is kept private and will not be shown publicly.
  • Lines and paragraphs break automatically.
  • Allowed HTML tags: <a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd> <blockquote><p><br>
  • Web page addresses and e-mail addresses turn into links automatically.

More information about formatting options

By submitting this form, you accept the Mollom privacy policy.