How many transactions can I send simultaneously?

Written by Killiane Menand

Published on August 1, 20241 min read

---

On Alchemy, the number of transactions you can send simultaneously is primarily determined by the availability of Compute Units (CUs) in your account and your readiness to allocate CUs for these transactions.

Understanding Compute Units (CUs) Consumption

Each transaction and API call on Alchemy consumes a specific amount of CUs. The amount of CUs required depends on the specific method or API being utilized. This means your capacity to send transactions concurrently is linked to your current CU balance and the CU cost of each transaction.

Impact of Compute Units Per Second (CUPs)

In addition to the Compute Units, the Compute Units Per Second (CUPs) also play a critical role in determining how many transactions you can send at the same time. CUPs measure the rate at which you can consume CUs in a given second, effectively capping the frequency of transaction submissions:

• Rate Limiting: If the cumulative CUs cost of simultaneous transactions exceeds your available CUPs limit, you will not be able to send all those transactions at the same moment.

• Managing Throughput: Understanding and managing your CUPs usage is essential for optimizing transaction throughput. This ensures that your application can maintain a steady flow of transactions without hitting rate limits.

Manage Your Compute Units

To effectively manage and plan your transaction capacity:

• Monitor Your CUs and CUPs Usage: Keep track of both the CUs each of your API calls consumes, this helps in forecasting and budgeting your usage.

• Review CUs and CUPs Costs: Familiarize yourself with the CU and CUPs costs associated with different methods and APIs. Understanding these costs is essential for optimizing the number of transactions you can send simultaneously without depleting your resources or exceeding your rate limits.