Why different download speeds on different PCs on the same network?

Question

Computer networks

Good day.

There is a large PC park (100+). I ran into a problem that on certain PCs the download speed from one local server (smb) does not exceed ~350Mbps. Moreover, Upload pours stably at 1Gbps. If I connect through another, for example, USB network card, then the speed is 1Gbps everywhere. On problem PCs, different network cards, tried different versions of drivers.
On all PCs 1Gbps, on the server 10Gbps.

Answer 1

Maybe I misunderstood the problem, but still.
At such speeds, the speed of recording on disks still greatly decides. Disks allow to download with such speed?

Answer 2

what OS? Go and QoS in the settings of the network card.

Answer 3

The problem was solved by moving from windows server to linux.