Mystery of Moving Files on Windows The puzzle revolves around transferring data between devices using Windows tools.
Mystery of Moving Files on Windows The puzzle revolves around transferring data between devices using Windows tools.
It’s common to see discrepancies between reported speeds and actual performance. When moving large files like 8GB, Windows may estimate higher speeds based on cached data or network conditions, even if the physical drive’s maximum bandwidth isn’t being fully utilized. The storage device itself might be limited by factors such as controller speed, interface type, or firmware constraints. Understanding these layers helps clarify why speeds can appear higher than what the hardware can sustain.
I understand how Windows can behave at times, especially with file transfer windows. It seems they've evolved since Windows 8, but functionality remains consistent. There might be hidden caching mechanisms at play that affect performance. You're not alone in wondering about these details!
They might have used a slower computer with a USB 2.0 drive to copy files at the same speed or even quicker than a modern Windows 10 system with USB 3.0.
I had precisely what I was thinking, but still, it doesn't matter that it's stored in RAM; the fact that RAM is extremely fast is completely unimportant since the entire process is limited by the slow hard drive. This is why I'm confused—because the speed of the source location doesn't matter.
The file system resided on your SSD, which explains the 800MB/s speed.
Windows utilizes leftover computer memory sections (DDR3, DDR4) for caching files. Because the 2TB hard drive isn’t likely set up for hot swapping or removal, Windows can store write instructions in RAM and pretend the process is done. It reads from the SSD at speeds of 300-550 MB/s via SATA ports, or faster with a m.2 drive. When an app requests writing data, Windows confirms completion instantly and quietly records the task, then begins transferring the data to the disk behind the scenes. This makes the application perceive rapid writes—often around 800 MB/s—while in truth the actual speed is much lower (100-200 MB/s for mechanical drives). The initial 3-4 GB are loaded quickly into memory, after which performance drops to match the drive’s capabilities.
Certainly, but sending data to a 7200RPM hard drive—something I’m familiar with from CrystaldiskMark—can reach up to around 270MB/s when writing sequentially.