Spare area and NAND size on 160GB 320/G3

[idata]

Please confirm the user-available area, spare area, and size of the NAND chips used in the 160GB G3. My understanding is that the 320-series uses a 10-channel architecture with 6.25% spare area as follows:

600GB: 640GB total area, 40GB spare area (6.25%), 20 x 32GB NAND, 2 NAND per channel

300GB: 320GB total area, 20GB spare area (6.25%), 10 x 32GB NAND120GB: 128GB total area, 8GB spare area (6.25%), 8 x 16GB NAND

Therefore, shouldn't the 160GB version have the following architecture?

150GB: 160GB total area, 10GB spare area (6.25%), 10 x 16GB NAND

According to the http://download.intel.com/design/flash/nand/325152.pdf product spec, the 160GB model has 312,581,808 sectors = 160,041,885,696 bytes of user-addressable space. In order to have 6.25% spare area, the SSD would need a total capacity of ~171GB. What is the size of each NAND chip? Or is it 160GB total area and 0% spare area?

[mmokk · Accepted solution]

the 'gb' in the labelled capacity is 1,000,000,000 bytes. 1gb of actual nand capacity is 1,073,741,824 bytes. if you redo the math, the 300gb and 600gb models have about 13% spare area.

the 120gb model can't be 8 x 16gb, as the controller is 10-channel, so it's actually 5 x 8gb + 5 x 16gb (like its x25-m 120gb predecessor).

160gb and smaller models have ~7% spare area, like the x25-m.

[idata]

Thank you very much for the explanation.