Using CAT7/8 vs CAT6 on VM on Gigabit Network

[yellowbananabus]

I had a question regarding my network transfer speeds. I am running a TrueNAS machine with 16 GB of RAM, an i5-4590, 2 SATA 1TB Hard Drives, and gigabit ethernet with a CAT6 cable. When I transfer a large file to and from the TrueNAS machine to my gigabit-capable laptop, it transfers roughly 100 megabytes/sec as expected. However, recently I set up a VM in my TrueNAS machine on the 2nd hard drive (1st hard drive has all of my data), and transfer speeds to and from the VM and TrueNAS file server (i.e. 1st hard drive) was capped at 50 megabytes/sec. Could this be due to the CAT6 cable not being able to handle the bandwidth to and from the machine simultaneously and if so would upgrading to a CAT7 or CAT8 cable solve this issue? If not, does anything come to mind that would be the cause of this bottleneck? Thanks!

 

[yellowbananabus]

I had a question regarding my network transfer speeds. I am running a TrueNAS machine with 16 GB of RAM, an i5-4590, 2 SATA 1TB Hard Drives, and gigabit ethernet with a CAT6 cable. When I transfer a large file to and from the TrueNAS machine to my gigabit-capable laptop, it transfers roughly 100 megabytes/sec as expected. However, recently I set up a VM in my TrueNAS machine on the 2nd hard drive (1st hard drive has all of my data), and transfer speeds to and from the VM and TrueNAS file server (i.e. 1st hard drive) was capped at 50 megabytes/sec. Could this be due to the CAT6 cable not being able to handle the bandwidth to and from the machine simultaneously and if so would upgrading to a CAT7 or CAT8 cable solve this issue? If not, does anything come to mind that would be the cause of this bottleneck? Thanks!

P.S. I have tried changing TCP offloading settings, and though it does speed up for a bit, it drops to sub-10 megabytes/sec speeds constantly. Also regarding that subject, this also happens occasionally with it enabled, so what could be the cause of the occasional drops in transfer speeds that occur?

 

[Morris]

P.S. I have tried changing TCP offloading settings, and though it does speed up for a bit, it drops to sub-10 megabytes/sec speeds constantly. Also regarding that subject, this also happens occasionally with it enabled, so what could be the cause of the occasional drops in transfer speeds that occur?

I'm running a Windows 10 VM and network speed seems to be normal, yet disk I/O is very slow. This may be what you are experiencing.

Another taught, make shore you have loaded the virtual driver package and are using the VirtIO NIC type. The Intel V1000 is extremely slow. Also the Disk must be in VirtIO mode as AHCI is even slower.

 

[jgreco]

Could this be due to the CAT6 cable not being able to handle the bandwidth to and from the machine simultaneously and if so would upgrading to a CAT7 or CAT8 cable solve this issue? If not, does anything come to mind that would be the cause of this bottleneck? Thanks!

No, Cat5e and Cat6 should both be able to handle gigabit ethernet. It might not if you have a bad cable or connector. Typically you would test this using iperf or iperf3, look to see what the link speed is, look for any errors being reported by the switch and ethernet interface, etc.

Be aware that many laptops have crappy ethernet chipsets that may not be able to hit anywhere near gigabit.

Once you eliminate the network as a potential source of trouble, you can look for other issues.