Windows 11 Beta preview build 22635.570 shows a subtle change in Task Manager. Memory speed in this version is now measured by MT/s (Megatransfers per second) instead of MHz (Megahertz).
As a result, the speedometer within Windows 11 finally matches the metric memory manufacturers communicate to customers. Those purchasing DDR4 memory with a speed of 3200 MT/s would normally see 1600 MHz as the speed within Task Manager, for example
The new Windows 11 change in the beta release was first noticed by X user PhantomOcean3.
MT/s and MHz
Both measurements are correct, but the discrepancy between the numbers can be confusing to users. Modern system memory uses Double Data Rate (DDR), which can pass two values per clock cycle. This means the MHz (number of clock cycles) value is half the MT/s count (the number of transfers), although users typically use the higher number to refer to the speed of system memory.
The fact that Task Manager still shows the lower number repeatedly leads to support questions about the surprisingly low reading. Microsoft seems to want to get rid of that confusion.
Interestingly, yours truly is seeing yet another incorrect value on this computer. The DDR4 memory runs at 3200 MT/s, but Task Manager shows an incorrect value of 3200 MHz. This is on an up-to-date version of Windows 11 23H2. Irregularities like this are more common, as it turns out. For example, for one user on Reddit, the speed of the installed DDR5 memory seemed to display both 4800 MT/s and 5200 MT/s simultaneously.
Also read: Block on Windows 11 updates for certain Intel PCs lifted after 2 years