# Technical Analysis of Memory Cost Chart
## Chart Type
Horizontal stacked bar chart comparing memory cost (GB) across neural network optimization models.
## Axis Labels
- **X-axis**: Memory cost (GB) [0, 10, 20, 30, 40, 50, 60]
- **Y-axis**: Neural network models (listed top to bottom):
1. BF16 AdamW
2. Adafactor
3. AdamW (no retaining grad)
4. 8-bit Adam
5. 8-bit Adam (no retaining grad)
6. 8-bit GaLore (no retaining grad)
## Legend
Bottom-right corner with color-coded components:
1. **Dark Brown**: Weight
2. **Light Brown**: Activation
3. **Green**: Optimization
4. **Light Green**: Weight Gradient
5. **Pale Green**: Others
## Embedded Text
- Red dashed vertical line at **30 GB** labeled **"RTX 4090"** in red text.
## Key Trends
1. **BF16 AdamW** (longest bar):
- Total memory cost: ~58 GB
- Component breakdown:
- Weight: ~15 GB (dark brown)
- Activation: ~3 GB (light brown)
- Optimization: ~25 GB (green)
- Weight Gradient: ~10 GB (light green)
- Others: ~5 GB (pale green)
2. **Adafactor**:
- Total memory cost: ~45 GB
- Component breakdown:
- Weight: ~12 GB
- Activation: ~3 GB
- Optimization: ~18 GB
- Weight Gradient: ~10 GB
- Others: ~2 GB
3. **AdamW (no retaining grad)**:
- Total memory cost: ~44 GB
- Component breakdown:
- Weight: ~14 GB
- Activation: ~3 GB
- Optimization: ~22 GB
- Weight Gradient: ~5 GB
- Others: ~1 GB
4. **8-bit Adam**:
- Total memory cost: ~42 GB
- Component breakdown:
- Weight: ~13 GB
- Activation: ~3 GB
- Optimization: ~15 GB
- Weight Gradient: ~10 GB
- Others: ~1 GB
5. **8-bit Adam (no retaining grad)**:
- Total memory cost: ~30 GB
- Component breakdown:
- Weight: ~15 GB
- Activation: ~3 GB
- Optimization: ~10 GB
- Weight Gradient: ~1 GB
- Others: ~1 GB
6. **8-bit GaLore (no retaining grad)**:
- Total memory cost: ~22 GB
- Component breakdown:
- Weight: ~12 GB
- Activation: ~3 GB
- Optimization: ~5 GB
- Weight Gradient: ~1 GB
- Others: ~1 GB
## Spatial Grounding
- Legend positioned at **bottom-right** (coordinates: [x=0.85, y=0.15] relative to chart area).
- Red dashed line at **x=30 GB** spans full chart height.
## Component Isolation
1. **Header**: Chart title implied by axis labels.
2. **Main Chart**: Horizontal bars with segmented components.
3. **Footer**: Legend and RTX 4090 reference line.
## Trend Verification
- All models show **Weight** as the largest component (dark brown).
- **Optimization** (green) dominates in BF16 AdamW and AdamW variants.
- **8-bit GaLore** has the smallest total memory footprint, with **Optimization** reduced to ~5 GB.
- **RTX 4090** reference line (30 GB) separates models into high/low memory usage groups.
