[Home](./index.md) > [bitburner](./bitburner.md) > [NS](./bitburner.ns.md) > [upgradePurchasedServer](./bitburner.ns.upgradepurchasedserver.md)
## NS.upgradePurchasedServer() method
Upgrade a purchased server's RAM.
Signature:
```typescript
upgradePurchasedServer(hostname: string, ram: number): boolean;
```
## Parameters
| Parameter | Type | Description |
| --- | --- | --- |
| hostname | string | Hostname of the server to upgrade. |
| ram | number | Amount of RAM of the purchased server, in GB. Must be a power of 2 (2, 4, 8, 16, etc.). Maximum value of 1048576 (2^20). |
Returns:
boolean
True if the upgrade succeeded, and false otherwise.
## Remarks
RAM cost: 0.25 GB