Minisforum MS-A2 - intel x710

[xsniper89]

Hello everyone,
I’m running into a strange network performance issue on Proxmox that I haven’t been able to resolve, and I’m hoping someone here might be able to point me in the right direction.
The problem affects both the Intel X710 NIC and the Realtek NIC on my Minisforum MS-A2. For some reason, upload speeds are severely limited, both on LAN and WAN, while download is only partially affected.

Expected vs Actual Speeds​

My WAN connection is 2.5 Gbps up/down.

On Proxmox (9.1.2), I get:

• Download: ~1.7 Gbps
• Upload: ~200–400 Mbps

On my Unraid server (same switch, same VLAN, same router, 10 Gbps NIC), I get the full 2.5 Gbps up and down without any issues.

Current Network Topology​

ONT → UniFi Gateway Max → Unmanaged QNAP Switch (4×2.5G + 2×10G) → Proxmox (Minisforum MS-A2)

Proxmox (9.1.2) Host Specs:

• Minisforum MS-A2
• Ryzen 9955HX
• 96 GB DDR5
• 3 TB storage
• Intel X710 + onboard Realtek NIC

What I’ve Already Tried​

• Bypassed the switch and connected Proxmox directly to the router → same results
• Swapped ports and cables
• Changed SFP modules
• Enabled/disabled flow control
• Removed and re-created VLANs
• Forced link negotiation
• Checked NIC temperatures
• Updated Intel X710 firmware and drivers
• Verified that nothing is saturating CPU or disk

No change at all.

iPerf3 Testing​

• When Proxmox is the client, connecting to an external iPerf3 server:
  • I previously saw many Retr (retransmissions)
  • Now I get poor results with almost no retransmits showing
• When another machine is the client and Proxmox is the server:
  • I still see 40+ retransmits
  • Throughput is inconsistent

Even stranger:

• WAN speedtest on Unraid: full 2.5 Gbps up/down
• WAN speedtest on Proxmox (same switch, same VLAN):
  
  • ~1.7 Gbps down
  • ~200–300 Mbps up

This makes it seem specific to Proxmox or the host networking stack rather than the rest of the network.

What I’m Looking For​

At this point, I’m a bit stuck and running out of ideas. I’d really appreciate guidance on:

• What else I should check on the Proxmox side
• Known issues with Intel X710 on Proxmox
• Offloading, MTU, queue settings, or kernel tuning recommendations
• Any similar cases you’ve seen before

If there are any logs, configs, or test outputs that would help, I’m happy to provide them.


Thanks in advance for any help!