Multiplayer performance issues

I had the same problem when it comes to the mini freeze thing you are mentioning, i think it's something to do with the CPU performance dips since it's most probably happening exclusively in the multiplayer. What fixed it for me were the following 3 tweaks:

1) Download the program "ParkControl", Launch it before starting the game, set it to "High Performance", Everything on "Disable", put everything on 100%, then Apply.

2) Add this line in the BF1 folder in your Documents>BF1>Settings>PROFILE_profile> "GstRender.Thread.MaxProcessorCount 8".      Put the number at the end corresponding to the number of the CPU cores you have, in my case 8.

3) Disable DX12 from your game.

As for the hard drive, i've heard players complain with performance when the game switches rounds, my best advice is get a SSD and store the game there, this game is pretty big and it consumes a lot of storage and it has to access that storage pretty fast. I had similar issues with NFS 2015, which also uses the frostbite engine, the game was on my HD and the roads randomly disappeared, i constantly fell under the map, so yeah...

Oh wait the mini freezing is happening in single player too, though not nearly as bad as in multiplayer. Most of the time it seems to happen in single player during those cutscenes when it loads the level. Perhaps it has something to do with the fact that I have only 8gb ram. Task manager shows the game is using 83-84% of my memory.

I manage to play it smoothly with 6gigs, the tweaks i mentioned cleared the stutters compared to the mess it was before, it starts lagging mostly when i have stuff open in the background, when playing too much and when alt and tabbing, other than that it runs like butter

Thanks. I didn't do exactly as you said but it prompted me to find something that may have actually improved my performance. I simply changed the power management settings of windows from "balanced" to "maximum performance." Not sure yet. I tested it with single player cutscenes. Yesterday my game had these micro freezes constantly whenever  it was loading the level during a cutscene. But now it didn't happen. And seems like I got into a multiplayer  match a bit faster than before (although my hard drive light still stays on without blinking when it loads the map/level.) I cannot say for certain that it worked but so far it looked promising.

If you don't count the freezes and lagging, this game is wonderfully optimized by the way. I have a factory overclocked msi gtx 750ti that is more or less equal to a gtx 660 (can't say for sure) and I get 60 fps with low settings and between 40-60 at medium (it stays pretty steady most of the time, no major drops.)

Well apparently didn't fix my issue entirely. It just delayed it. Now I can play for about 3 hours before it starts freezing and stuttering. Most likely a ram issue.