Low Bandwidth on Virtual Machine

[virtuoso]

I am currently testing truenas on vm with windows host for a friend, but the bandwidth is too low, around 280-300Mbps, falling below 150Mbps most of the time. For comparison, we're running pihole as another vm with identical settings and getting around 5-5.5gbit/s, which is expected.

Note, all tests were made using the host computer, so cabling or switches shouldn't be an issue but we're using 3ft cat6a cables connected to a 2.5g switch.

Truenas network interface is reporting 1000baseT even though I can pull full 2.5gbit from host, but even then, we're not pulling anywhere near 900-1000Mbps.
If I missed anything, please let me know so I can provide more details.

Pihole:

Truenas on a good day:

 

[somethingweird]

Welcome! it be nice if you provide hardware specs?

 

[virtuoso]

Welcome! it be nice if you provide hardware specs?

Hi! Here are the specs;

12600k, slightly overclocked
MSI mpg z690 edge
64gb ddr4 3600mhz
4070 ti

This is his main pc where it's on 24/7 and only intends to use Truenas and pihole other than gaming and remote working. He is running both using Virtualbox on a Windows machine and I set 8 threads and 32gb ram to Truenas, and 2 threads and 2gb ram to pihole. I know virtualizing is not ideal but this is what we have here.

Networking is done by a 5 port 2.5g and 8 port gigabit switch, which connects everything except phone, tablet etc.

I set up two pools consisting 5 and 2 4tb sata hard drives, first raidz1 for backups and second stripe for games library.

 

[virtuoso]

Update: I just installed Truenas Scale with exact same hardware allocation and VirtualBox settings, and the bandwidth is like this:

Definitely better than the current truenas instance. It seems like a problem with Core's network setup. Also, just realized I never told the first one was Truenas Core.