Copy times for K32 plot files

Since I’m slinging around these large ~101gb k32 plot files all the time now, I find it handy to know exactly how long it’s gonna take to copy plots based on the megabytes per second of throughput I am seeing:

copy speed time copy speed time
2000 MB/sec 0:51 175 MB/sec 9:50
1000 MB/sec 1:43 160 MB/sec 10:46
650 MB/sec 2:39 150 MB/sec 11:29
600 MB/sec 2:52 140 MB/sec 12:18
500 MB/sec 3:26 130 MB/sec 13:15
450 MB/sec 3:49 111 MB/sec 15:31
350 MB/sec 4:55 50 MB/sec 34:28
250 MB/sec 6:53 33 MB/sec 52:14
200 MB/sec 8:37 10 MB/sec 2:52:22

(I may make this into a graph later)

I bolded two;

  • 111 MB/sec is typical gigabit ethernet throughput speeds for a wired network.
  • 200 MB/sec is around the typical write speed I’ve seen from external single big 3.5" hard disks… but it can degrade so that’s a best case scenario. I often see it slip down to 175, 160, 150, 140, 130 as the drive fills or just… I don’t even know. But I’ve never seen a single large drive do better than 235MB/sec reads.

I was so out of touch with 3.5" HDD speeds since I’ve been an all-SSD guy for, gosh, almost a decade now. I’ve seen max 250mb/sec reads and max 235mb/sec writes with the larger drives.

USB speeds are also relevant and can be a bottleneck:

  • If the port isn’t labeled, it’s probably standard USB and 5gbps.
  • If the port says “SS” it is superspeed and 10gbps max.
  • If you are really lucky, the port says “SS 20” and it is the latest & greatest 20gbps max.


port speed k32 101gb copy time
USB 5 gpbs 2:57
USB SS 10 gbps 1:28
USB SS 20 20gbps 0:44
Thunderbolt 3 40 gbps 0:22

I have found it is very difficult to hit these speeds due to interface and controller overhead. In my experience you get more like 660mb/sec (3 min) writes on USB SS 20 / TB3 and 330mb/sec (5 min) writes on USB SS.

Anyway, the TL;DR is you’re doing great with traditional spinning disks if you are seeing 10 minutes k32 plot copy time or less.


thanks for this overview, the numbers are in line with what I’m seeing here. Before Chia I haven’t touched mechanical drives for years and it is indeed astonishing, how slow they are in many cases. It’s so easy to forget about how far the technology has come.

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