Macbook pro waiting too much between phases

Hi guys and gals!
I have macbook pro 16" 2019 with 16gb ram - 1tb nvme ssd (built in) - i9 (8 core-16 threads)
And i use chia software.

I have a problem about plotting. My computer waits too much at %31 and %100 (like 4 hours)
with this setup i can just run 3 plots in parallel and it takes around 12 hours.

  • I checked the files and they are still .tmp
    I dont understand why my computer waits too much at %31 and %100.
    Possible reasons:
    1- Mac OS installed on my temporary space. So i need to get external nvme for temp space.
    2- My 2tb wd elements desktop hdd connected to the Overhub | Elektron which dont have power adapter. So i need to buy a new usb hub with adapter.
    3- My macbook pro also farming.

After your advices i will continue my investments.
Also here is the logs:

Plot size is: 32
Buffer size is: 3390MiB
Using 128 buckets
Using 2 threads of stripe size 65536

Time for phase 1 = 12779.697 seconds. CPU (145.780%) Thu May 20 09:48:08 2021

Time for phase 2 = 4627.041 seconds. CPU (98.720%) Thu May 20 11:05:15 2021
Wrote: 268

Total compress table time: 1325.664 seconds. CPU (96.940%) Thu May 20 13:37:34 2021
Time for phase 3 = 9138.685 seconds. CPU (98.140%) Thu May 20 13:37:34 2021

Time for phase 4 = 596.988 seconds. CPU (99.060%) Thu May 20 13:47:31 2021
Approximate working space used (without final file): 269.305 GiB
Final File size: 101.334 GiB

And it still waiting at %100. Please help me :blush:

What are you using for your tmp directory when plotting, the HDD or your internal SSD? (Do not recommend using internal SSD on a Mac long term as plotting creates alot of wear on an SSD)

The long pause at 100% is usually caused by the copy of the plot from the tmp directory to the final plots directory. Should be in the 10ish minutes time to copy to a HDD. More if parallel copies occurring or drive is otherwise busy.

With the amount of RAM in your computer 3 plots is probably the most you should run (maybe 4 but suspect you’ll start swapping which isn’t good).

1 Like

Thank you for fast response. I use my internal ssd (i mean mbp’s nvme) for plotting.
I will plot 36tb for the first stage of my investments. so it means around 72tb for temporary space, which means nothing for ssd life (total bytes to written) if im not wrong :slight_smile:

Every plot you create does 1.3 TB of writes in the plotting process. So for every 1 TB of plots you create that is approximately 12 TB of data written to tmp space during creation. Depending on what grade of SSD Apple uses in the MBP that could be a hit (36 * 12 = 432 TBW). Not enough to kill it but definitely shorten the life noticeably. For what Apple charges for SSD I’d like to think they are using data center grade SSD (I.e. lots of over provisioning) but they don’t say and I’ve never seen any test where someone tested the SSD lifetime in a MBP.

So you advice me to buy external nvme.
As i read people use gen4 nvme with thunderbolt 3 enclosures. do it works ? And do you think my plotting time will be decreased?

I doubt you need a gen4 SSD. gen4 gets you more bandwidth which is good if you are trying to do many plots in parallel (say 6 or 8). You are limited to 3 or 4 in parallel (based on amount of RAM) for which a gen3 SSD should be fine. If you can get a gen4 for about the same price then go for it but I wouldn’t pay much extra for it. Also finding a gen4 thunderbolt 3 enclosure may be a challenge. Most that I’ve seen are all gen3 but maybe someone has come out with a gen4 now.

I wouldn’t expect an external SSD to be faster than the internal.

With regards to your plotting speed, your CPU utilization is good. Phases 2-4 are single threaded and you got almost 100% CPU utilization. (Hopefully none of this was performing swapping, I’d definitely monitor for swap activity while figuring out how many plots will run in parallel.) This may be how long it takes. A MBP runs on a mobile processor (typical speed 2.5 GHz); single threaded performance of a core is key. The mobile processor can burst to faster clock rates but only for short periods of time, they don’t have giant heat sinks that let them run at these faster rates for long periods of time. Desktop machines clocking at 3.5 to 4.0 GHz are going to be faster.

I’m using the same mbp with 64GB ram but using only external nvme ssds for temp and external 10TB HDDs for storage.
Yes, I don’t want to plot in the internal drive as - MBP internal drive is not removable (will have to replace motherboard if the internal ssd stops working)

So I’m using Samsung’s 980 nvme with usb-c enclosures. Thats giving me 950MBPs …
Internal nvme gives >2.5k MBPS.

I used internal nvme for the first few plots , it took ~5 hours per plot.

thank you for details did you try it with thunderbolt 3 enclosure ? and what is the parallel plotting speed with samsung 980 ?

4 plots / day / drive.
I have 2x samsung 980. So 8 plots per day.
Parallel plot config :
4plots parallel with 60 to 90 mins stagger time. 28gb ram and 8 threads. (just throwing more ram and threads as I have surplus of both :joy: )