MT/s vs. MHz: Accuracy in Measuring Memory Speed

When it comes to measuring memory speed, one of the most historically used measurements for memory performance is megahertz (commonly abbreviated as MHz). However, after years of debate between manufacturers, experts and gamers alike, many, including our team here at Patriot Memory, have started to refer to a different, more accurates means of measuring memory speed: megatransfers. Let’s talk about megatransfers, megahertz, their key differences and why megatransfers has become the newest, more accurate standard for memory speed.

Megahertz (MHz)

First, let’s set the stage for megahertz and what it means in the context of memory. Hertz is a basic unit for frequency on the basis of one cycle per second. Megahertz describes one million total cycles in a second. Therefore, megahertz has become a standard identifier in the frequency of repetition of digital signals through waveforms as binary code. This repetition of information between components or, in this case, between a motherboard and DRAM will be described in MHz. This would describe speed under the conception of one data transfer per clock cycle from before the addition of more than one clock cycle, as we'll discuss below.

Megatransfers (MT/s)

Similar to that of hertz, transfers describes the amount of data transferred, equal to one megabyte per transfer. However, transfers will instead measure the speed at which real data is transferred between components instead, accounting for a clearer reading of the performance of memory. When applied with the creation of Double Data Rate (DDR) RAM, this measurement became more applicable on the basis of memory’s increase in both data transfer and the addition of another clock cycle. Therefore, transfers becomes a more applicable measure of true performance than hertz.

The Accuracy of Megatransfers (MT/s) vs. Megahertz (MHz)

Overall, MT/s has become a more accurate measure for DRAM performance than MHz for its specificity and application of what performance means in DRAM. The measurement of data transfer in megabytes as opposed to frequency or clock speed gives a more accurate reading not only on the memory’s performance itself, but also for better pairing performance with GPUs.

Why Does This Difference Matter?

The difference can be very important to understanding the correct performance of memory modules’ ability to perform in a gaming context. For example, consider our Viper Venom DDR5 that is currently available in 32GB (2 x 16GB) 7,400MT/s kits. If its actual data transfer rate is 7,400MT/s, this will mean that the Viper Venom DDR5 is operating at a 3,700MHz clock cycle. This establishes the difference in its frequency and its transfer rate. 

Conversely, it’s common to see speeds represented as megahertz that actually refer to megatransfers. DRAM modules might be labeled as, for example, offering “ up to 6,600MHz” when describing its performance. In reality, this will actually represent 6,600MT/s for accuracy purposes, but its clock cycle will be operating at a 3,300MHz rate instead. Therefore, this distinction can be helpful to remember when gauging the true performance of memory.

Ultimately, megatransfers represents the shift towards more accurately measuring performance in memory in time where accuracy is everything.