I can find precious little information on networking performance tuning under Vista. Is there a way to enable jumbo frames in Vista? I'm trying to improve/optimize file sharing performance between two PCs in a network. 1. One has an Intel PRO/1000CT and the other a Pro/1000PL. Both allegedly support jumbo frames. They're connected to a Linksys WSVR4400N router/switch and are at gigabit full duplex. (Turned autonegotiation off for all adapters.) 2. On the switch, set size for all ports to 9,014 bytes. 3. The PRO/1000CT PC running Vista (Home Premium) does have a "jumbo frames" option in the default driver that shipped with the OS, and I turned that on. 4. The PRO/1000PL PC running Vista (Ultimate) has no "jumbo frames" option for the driver... hmm. 5. I don't believe there is a disk bottleneck, as reads/writes are both to pretty fast disk... I'm currently getting no more than 20MB/sec (20 megabytes/second) and kind of expected more. Let me know!