Question Samsung 960 EVO SSD dipping below 80 mb/s?

[Cantreadlol]

Hey guys,
So I have this M.2 NVME SSD that is 1 year old that I recently thought to test my real transfer speed on. When I copy 1 large file (doesnt matter which size) initially the SSD starts at around 600-800 mb/s and then lika a sinus curve dips down quite a couple hundred of mb/s until it goes down to around 50-80 mb/s. It does so everytime, and after just a couple of seconds. When it goes down to those numbers it burst up to around 200 and then goes back down. It does so for the whole remainder of the transfer. I have all the newest driver, samsung magician gives me decent read and write speed of 3000 and 1500 (3200 and 1500 are whats advertised). Any thoughts on this issue?

Running on a MSI krait gaming 3x, Asus strix oc 1070 and i5 6600k

Picture of file transfer and graph:
https://www.dropbox.com/s/f3c0xna0m5tgofi/12gb test.png?dl=0

 

[rgd1101]

copying from and to the same ssd? what size? how full it is?

 

[mdd1963]

Check CrystalDiskMark sequential transfers...mine is about 3000 MB/sec reads, 1500 MB/sec writes...; if you see similar numbers (or better, as mine is 2/3rds full), it is working fine, perhaps you are seeing other bottlenecks unrelated to the 960 EVO, such as source file structure, 1 GbE network speed limitations at 113 MB/sec, etc)

Make sure you have write caching enabled in device mngr/disk drives/960 EVO/policies...

 

[popatim]

Transfers happen at the speed of the slowest device in the chain.
What are you transferring from? I'm guessing an HDD.

 

[Cantreadlol]

Thanks for the replies,
Im copy-pasteing a 12gb video within the SSD (so that it writes and reads it at the same time). Not using my HDD at all. My SSD is a 250 gb samsung 960 EVO, it is currently around 80% full.
Crystaldiskmark shows a seq read and write of 3100 and 1500 respectively. Ive tried it all, benchmarking my SSD shows advertised speeds, while real Life transfer speeds arent consistent. It Always start high and then goes down to around 50-80 mb/s and then just gains spurts to around 200 and then goes back down.
Worst part is, support-wise I am getting no help since apparently I need a landline to Contact samsung SSD centre to get help, and somehow out of all parts in my build this is the one who lacks a receipt, so I cant Contact my retailer either (where i bought it from). So I don't really know what to do here besides having to pay Money to get a expert have a look at this.
Really dissapointed in samsung service this time.
Edit: yes write caching is enabled. I have tried with different types of files, I have only been trying with large files and its the same. I dont Think anythings is bottlenecking since this is a pretty decent ''high'' end PC that is only 2 years old.

 

[rgd1101]

copy some data out to about 50% used