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Community Manager
1,017 Views

## Spare area and NAND size on 160GB 320/G3

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 NAND

120GB: 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?

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1 Solution
New Contributor II
117 Views

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.

2 Replies
New Contributor II
118 Views

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.

Community Manager
117 Views

Thank you very much for the explanation.