# RAM

## Characteristics

Name Unit Default value Description Example
units None 1 RAM strip quantity 2
usage None See Usage See usage ..
capacity Go 32 Capacity of a ram strip 12
density cm2/Go 0.625 Size of the die per Go of a ram strip 1.25
process nm None Engraving process (Architecture) 25
manufacturer None None Name of the ram manufacturer Samsung
model None None .. ..

## Complete

The following variables can be completed

### density

if process or/and manufacturer are given, density can be retrieved from a fuzzy matching on our ram repository. If several ram matches the given process or/and manufacturer the maximizing value is given (in terms of impacts).

## Manufacture impact

For one RAM bank the manufacture impact is:

$\text{RAM}_\text{manufacture}^\text{criteria} = (\text{RAM}_{\text{capacity}} / \text{RAM}_{\text{density}}) * \text{RAM}_\text{manufacture_die}^\text{criteria} + \text{RAM}_\text{manufacture_base}^\text{criteria}$

with:

Constant Units Value
$$\text{RAM}_\text{manufacture_die}^\text{gwp}$$ kgCO2eq/cm2 2.20
$$\text{RAM}_\text{manufacture_die}^\text{adp}$$ kgSbeq/cm2 6.30E-05
$$\text{RAM}_\text{manufacture_die}^\text{pe}$$ MJ/cm2 27.30
$$\text{RAM}_\text{manufacture_base}^\text{gwp}$$ kgCO2eq 5.22
$$\text{RAM}_\text{manufacture_base}^\text{adp}$$ kgSbeq 1.69E-03
$$\text{RAM}_\text{manufacture_base}^\text{pe}$$ MJ 74.00

Note: If there are more than 1 RAM bank we multiply $$\text{RAM}_\text{manufacture}^\text{criteria}$$ by the number of RAM bank given in units.

## Usage impact

Both power consumption and consumption profile are implemented.

## Consumption profile

The RAM consumption profile is of the form : consumption_profile(workload) = a * capacity

As a first approximation, we use a uniform consumption profile since the stress test data used show a rather uniform consumption. Consequently, the workload won't be used.

New stress test data specifically on RAM calls should be conducted to specify this consumption profile.

### Determining the parameters

To determine a we averaged the electrical consumption of RAM per GB. With the process we came up with a=0.284

Capacity is either given by the user or the default value is used.

consumption_profile(workload) = 0.284 * capacity