Delayed data movement across a 2.5 Gig connection
Delayed data movement across a 2.5 Gig connection
I aim for quick file transfers between my main PC and another device. Both have only 1Gig onboard, so I added two 2.5Gig cards. I didn’t use a switch or router and didn’t pay extra. Instead, I connected the two PCs directly with a standard Cat 6 crossover and set up IP addresses manually on each. It functions properly. Now I’m wondering if you open that PC’s IP in Explorer and Windows File Explorer knows to use the correct path (the 2.5Gig connection, not the 1Gig). When copying files, speeds appear around 125MB/s peak and 96MB/s average. IPERF 3 shows 300MB/s peak, which seems to match the 2.5Gig capacity. I also turned on Jumbo Frames on both cards for testing. There’s a mention about host offload—can that be turned off to free up CPU resources? It’s enabled by default. Is this actually using the new 2.5Gig cards, or am I still relying on the older 1Gig setup? Also noted, this was an NVMe-to-NVMe transfer, and I tried disabling the 1Gig connection.
These values seem unusual because they don’t fit standard setups; they likely need a switch or revert to a higher speed like Gigabit.
I made some adjustments to increase the link speed from auto to 2.5G. The main fix came from manually adding the Realtek driver in Windows 11. The OS now installed its own driver, which improved performance significantly—from a max of 115MB/s to around 216MB/s during testing, then down to 165MB/s. I’m satisfied with this change and hope it remains stable. The drop might have been related to NVMe caching or SMB handling. Testing with bigger files and a large game installation (47GB) gave consistent 230MB/s from SATA to NVMe drives. The real issue seems resolved, though I’m curious about the exact cause of the reduction.