RN104 file transfer speeds

Hello,

     I've always had my rn104 connected to a gigbit ethernet switch and I get 10 - 12MB/s file transfer speeds to my windows 11 pc.  I set static IP addresses on my nas and pc, ran a short(6ft) cable directly between the 2 and I'm only getting 15 - 16MB/s.  I expected much more.  Any Ideas as to why so slow?  The RN104 has old 5400 rpm desktop 4TB hard drives.  Could they slow transfers down that much?

Thanks for any assistance rendered,

Tom