I wonder if this could be a factor in Windows 10 as well?
"
Network Throttling IndexApplies to Windows 7, 8, 10, 2008 Server, and 2012 Server. Setting can be applied using the TCP Optimizer as well.
By default, Windows implements a network throttling mechanism to restrict the processing of non-multimedia network traffic to 10 packets per millisecond (a bit over 100 Mbits/second). The idea behind such throttling is that processing of network packets can be a resource-intensive task, and it may need to be throttled to give prioritized CPU access to multimedia programs. In some cases, such as Gigabit networks and some online games, for example, it is beneficial to turn off such throttling all together for achieving maximum throughput.
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Multimedia\SystemProfile
NetworkThrottlingIndex=ffffffff (DWORD, default: 10, recommended: 10 for media sharing, ffffffff for gaming and max throughput, valid range: 1 through 70 decimal or ffffffff to completely disable throttling)
It is only recommended to change this setting in saturated Gigabit LAN environments, where you do not want to give priority to multimedia playback. Reportedly, disabling throttling can also help reduce ping spikes in some online games."
i use Windows 10 Pro 64 bit, Intel 8265 AC MU-MIMO 867 Mbps, DIR-895L, all latest driver, and tried this tune :
https://answers.microsoft.com/en-us/windows/forum/windows_7-networking/very-slow-200kbsec-file-copy-between-win7-machines/b8736b1b-0a91-4567-ba33-215084ffc906
1. Running as Administrator in Command Prompt, type: "netsh int tcp set heuristics disabled"
2. Next, follow the instructions that Amrita wrote above.
First enter: "netsh int tcp set global autotuninglevel=disabled" and reboot.
Then enter: "netsh int tcp set global autotuninglevel=normal" to restore it to the typical setting.
3. Finally, go to Control Panel > Programs > Turn Windows Features on or off > and check "Simple TCPIP services (i.e. echo, daytime, etc.) so that it is enabled.
4. Reboot your system again, and the file transfer rates should be excellent.
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Speed improve from ~20 MB/s to ~30 MB/s, maybe Dlink can fix/improve firmware to make this faster like we use Killer 1535 adapter card..
will try this in Windows XP