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Altera_Forum
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17 years ago

4 GB SODIMM Bandwidth

Hi, How can I calculate the memory-bandwidth offered by a 4GB on-board SO-DIMM when I interface it with a Stratix EP3SL150 on a DE3 Board? Is this organized in 4 banks of 1GB? Can 1 contro...
Altera_Forum's avatar
Altera_Forum
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17 years ago

The available bandwidth from a DDR interface is determined by three things

  • The bitwidth (64 in your case)

  • The memory clock frequency (around 400MHz)

  • The access efficiency (in the 50% to 80% region)
Assuming burst accesses, without too much consideration for performance, then this would come out at

Bandwidth (bits/sec) = 64 * 400 * 2 (for DDR) * 0.5 = about 25Gbit/s

The number of banks is in the SODIMM datasheet, but the controller will correctly keep track of which ones are open.