Use this tool to calculate the memory bandwidth
Enter the following:
- Memory Clock Frequency – this is the clock frequency (in MHz) that is input to the memory module
- Bus Width in bits
- Clock multiplier is a factor depending on the memory type. In the case of DDR for instance this number is 2.
Formula
Memory Bandwidth = Clock Frequency * Multiplier * Bus Width * (1/8)
Example Calculation
- For a clock frequency of 500 MHz; multiplier of 2 and Bus Width of 256 Bits, the memory bandwidth is 32 GB/s.
What Is Memory Bandwidth?
Memory bandwidth refers to the rate at which data can be read from or stored into a semiconductor memory. It measures the amount of data that can be transferred across the memory interface per second (units are typically Megabytes per second (MB/s) or Gigabytes per second (GB/s)).
Bandwidth is an integral factor in determining the performance of the memory system, as it directly impacts the access speed and responsiveness of different memory components.
How much memory bandwidth do I need for gaming?
When it comes to gaming, the memory bandwidth requirement varies depending on the workload and the type of games being played. Generally, higher bandwidth is desirable for games with complex graphics and large datasets. Modern GPUs (Graphics Processing Units) and CPUs (Central Processing Units) have specific memory bandwidth requirements, and it is recommended to match the memory bandwidth to these specifications for optimal gaming performance. For instance Intel Core i9-13900K Processors have a max memory bandwidth specification of 89.6 GB/s. Use the calculator above to match with the spec.
Is memory bandwidth the same as memory speed?
No, memory bandwidth and memory speed are not the same things. While memory speed refers to the frequency at which data can be transferred within the memory module (indicated by the clock frequency specification in MHz), memory bandwidth measures the overall amount of data that can be transferred across the memory interface per second.
How to Increase Memory Bandwidth
If you’re looking to boost your system’s memory bandwidth, here are a few tips to consider:
- Choose memory modules with higher bandwidth capabilities, such as DDR5, as they provide faster data transfer rates. At the time of writing this post, the memory bandwidth of DDR5-7200 is the fastest at 57600 MB/s. To calculate this number use the transfer rate of 7200 MT/s in this calculator to find the effective bandwidth is 57.6 GB/s.
- Upgrade your CPU to a more powerful one with better memory handling capabilities.
- Optimize memory settings in the BIOS to ensure efficient utilization of memory resources.
- Consider using dual-rank memory modules, as they offer better memory bandwidth compared to single-rank modules.
- Ensure that your memory modules are compatible with your motherboard’s memory slots and support the desired memory speed.
By implementing these strategies, you can potentially increase your system’s memory bandwidth and enhance its overall performance.
Notes
Clock frequency, bus width and multiplier are often only known to digital designers. There’s another way to calculate bandwidth (MB/s) from the transfer rate specification (MT/s) on the memory module. Use the Mega Transfer per second to MHz and Bandwidth tool. As an example, for DDR4-2666 the transfer rate is 2666 Mega-transfers/second. The MT/s to BW tool gives 21.3 GB/s.