# tt_device_dram_total_megabytes

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## Name

### Prometheus Metric Name

```
tt_device_dram_total_megabytes
```

### Metric Path (tt-telemetry)

Schema:

```
{hostname}/tray{tray}/chip{chip}/dram/tt_device_dram_total_megabytes
```

Example path:

```
bh-glx-c09u02/tray1/chip2/dram/tt_device_dram_total_megabytes
```

## Description

The total DRAM capacity of the chip, in mebibytes (1 MiB = 1024×1024 B), rounded to the nearest integer. Computed as `dram_bank_size * num_dram_channels` from the chip's UMD `SocDescriptor`. The value is static for the lifetime of the process — it depends only on the chip's architecture and harvesting configuration.

This metric is the denominator for per-device DRAM utilization (`tt_device_dram_used_megabytes / tt_device_dram_total_megabytes`).

## Values

**Type:** Unsigned Integer

**Units:** Megabytes (MB) — reported as mebibytes (1 MiB = 1024×1024 B), rounded to the nearest integer.

**Allowable values:**
A positive integer reflecting the chip's installed DRAM capacity.

## Prometheus Labels

|Label Name|Value|
|---|---|
|hostname|The host from which the metric was collected.|
|hall|The datacenter hall where the host is located. Sourced from the Factory System Descriptor (FSD).|
|aisle|The datacenter aisle where the host is located. Sourced from the Factory System Descriptor (FSD).|
|rack|The rack number where the host is located. Sourced from the Factory System Descriptor (FSD).|
|shelf_u|The shelf U position in the rack where the host is located. Sourced from the Factory System Descriptor (FSD).|
|tray|The tray (UBB) that the device is located on.|
|chip|The ASIC location within the tray.|
|unit|The unit of measurement. Always `"MB"` for this metric.|