VNC Woes

skimmilk5 · January 15, 2020

(If this is the wrong forum, mods, please move. Thanks!)

I have a Mac Mini (mid-2012, Core i5 base model, 8GB RAM) that I use as a development server. I frequently use the built-into-macOS VNC services to access the desktop so that I can use applications like Xcode. I'm accessing this machine from a Windows 10 (version 1809, build 17763.914) computer running RealVNC's VNC Viewer software. I'm using the onboard 1Gbit NIC on the Windows machine (an Intel I219-V chipset), and the 1Gbit NIC on the Mac Mini (a Broadcom BCM57765 chipset), running through a HPE 2915-8G switch. On the switch, everything is configured on the same VLAN, and communications are working properly, with both computers reporting that the link speed is full duplex, 1000baseT. A quick CrystalDiskMark 7 benchmark shows that, with the Mac Mini mapped as a network drive to the Windows box and with the right data load, I'm definitely able to saturate the full gigabit link between the two machines.

Now's the issue: VNC services seem to be capped at "Fast Ethernet" speeds (100Mbit/s max). The VNC experience is usable, but not pleasant. There's dropped frames all over the place. I'm not doing anything computationally insane, like games; I'm using fancy text editors. I've tried a bunch of different things short of paying for a different VNC server solution, including but not limited to, changing color settings, changing the data rates of the VNC service on the Windows box, changing the quality settings of the VNC connection, resetting all of the networking settings, and even changing to "jumbo" packets (9000 MTU, instead of 1500 MTU). Even with all of these efforts, the data rate still seems to be capped by something, but I can't figure it out! Google searches tend to return forum posts from a decade and a half ago (the era of Windows XP and Mac OS X 10.5), from people that perhaps were trying to access their work machine from home, but my use case is much different than any of these.

I know that I need to run wired (my wireless experience would be decidedly garbage), and that for this particular application, I need to be running either through an edge switch (like my current solution) or using a crossover cable or a patch cable with one of the adapters set to auto MDI-X. Regardless of the configuration, VNC looks like it's limited to fast Ethernet speeds.

What would y'all recommend?

Windows7ge · January 15, 2020

10 minutes ago, kimsejin5 said:

VNC looks like it's limited to fast Ethernet speeds.

Should this be true it wouldn't be the only issue. VNC Viewer to my knowledge does not use GPU acceleration. It renders off the CPU. This will make for a poor choppy desktop experience. For a lot of server applications as a management tool it's fine but a daily driver it'd be miserable.

Look into something like PARSEC. It requires that the "server" have a GPU. It will use the GPU for rendering the desktop then copy the GPU's frame buffer over the network to your client. Makes for a snappy/responsive experience. Weather or not they support MacOS I can't say but it's something you can checkout.