I have a Dell Precision M6500 laptop on Windows 8 x64. I have the Broadcom Driver 188.8.131.52 from their site for my 5761E chipset. Under the NIC device in Device Manager, under Advanced, there is no option for enabling Jumbo Packets/Frames or setting the MTU (packet) size. Any other way to enable this? I would find it hard to believe this chipset doesn't support it.
I can get 70+ MB/s upload speeds to other PCs, but not to my Netgear ReadyNAS. However, another PC on my network gets at least 60 MB/s to this same ReadyNAS, but it didn't until I enabled Jumbo Frames. The NAS has a setting for it, and my switch does support it. If I turn off Jumbo on the other PC, I only get about 12-15 MB/s which is what I am seeing from this 5761E right now.
I also tried the Microsoft driver, and while there are more options on the advanced tab, I don't see the Jumbo Frames option.
Any ideas would be great.