@45lightrain ok so lets start with some basics.
a 1GbE link (under theoretical conditions) is 1 Giga bits per second or 128MB/sec or 7.5GB/min raw data. Understand that there is ethernet overhead and you will never achieve 7.5GB/min.
So how is it possible to see speeds above 7.5GB/min on a 1GbE link? Simply data compression. So what you are seeing in the part clone screen is a composite speed including fog server speed sending the data to the network, network transfer time, the client receiving the image, expanding in it memory, and then writing it to disk.
If you are getting 5.5-6.1GB/min in partclone on a pure 1GbE network your fog environment is well designed and network well managed.
I wrote an article a few years ago that has some benchmark tools you can use to see where you can get additional speed out of your setup. https://forums.fogproject.org/topic/10459/can-you-make-fog-imaging-go-fast
So the executive summary is that if you want to go fast.
Install at least (1) 10GbE network link. (If you have many computers running the fog clients, run (2) 10GbE links in lag configuration.
If you have many clients hitting your fog server while you are trying to image use a ssd disk or nvme drives on your fog server (I would look at spending here the last, typically its not the disk that is slow, unless you have just a single spindle hdd driving your fog server).
Try to get the 10GbE network as close to the target computers as you can.
If you are trying to image multiple target computers at the same time look into fog casting your image to the target computers.
When capturing your image use the zstd compression tool over gzip. Set zstd at compression 11 to start. If your target computers have a lot of horsepower, 16GB of ram, and fast nvme disks you can get more data through your network by compressing the data more. This will put a heavier load on the target computer expanding the image and writing it to disk.
Think if your imaging as 3 factor triangle. You have server speed to get the image to the network adapter, the speed at which your network can move the image to the target computer, and finally the time it takes for the target computer to intake the image, expand it in memory and write to disk. In the imaging process the fog server typically has the least impact on imaging of the three.