Question Is it Normal for Large File Copy to Slow Down?

[dannywg]

Built Ryzen7 tower with MSI MPG X570S Edge MAX Gaming mobo. Samsung 970 EVO Plus 1TB NVMe as system drive. Testing write speeds 76GB video files. Noticed that file transfer (60 seconds total) initially very fast but speed drops. Write speed begins at 1.8GBps then drops to 800MBps halfway through. I originally installed WD Green SN350 which dropped to under 100MBps -that's why I swapped with the Samsung 970 EVO.

Hardware Monitor shows drive temp increased to 43C during copy. Is the system throttling transfer to maintain health of drive? Perhaps the cache can't keep up? Is this normal? I have tested portable NVMe drives like Crucial X8 1TB which failed under heavy load. I thought installing in a modern PC with large heat sink and fans would be more stable.

 

[USAFRet]

Yes, this is normal.

Once the cache space fills up, the transfer speed slows down.

Also, transferring data from what other drive?

 

[Lafong]

Throttling temps are likely to be somewhere near 80. That's what Intel uses and I wouldn't expect Samsung to be drastically different. I'd suspect a caching issue.

 

[dannywg]

Yes, this is normal.

Once the cache space fills up, the transfer speed slows down.

Also, transferring data from what other drive?

Thanks for info USAFRet,
I was only testing and did copy/paste 76GB folder of videos on same drive -system drive.

 

[USAFRet]

Thanks for info USAFRet,
I was only testing and did copy/paste 76GB folder of videos on same drive -system drive.

Copy from what?
Within the same drive?


Yes, this will absolutely show exactly what you see.

 

[dannywg]

Throttling temps are likely to be somewhere near 80. That's what Intel uses and I wouldn't expect Samsung to be drastically different. I'd suspect a caching issue.

Thanks Lafong,
Though not desirable it is good to know my drive is not defective. I recall copying files on old computers using 7200 rpm mechanical drives and have more stable write speeds. But then 100MBps doesn't require a lot of cache.