Hi Brad, I have two dell servers, one is an R515 with 12 x 4TB SAS, this is mainly a farmer but it has enough spare CPU to be doing 4 parallel plots most of the time. I plot to the SAS drives selecting for example drive E as the final destination, drive F as temp1 and drive G as temp 2. Once E is filled I will move down a drive letter.
The other machine is an R720 dual E5-2650v2 with 8x 3TB SAS similar to your HP, but I got a deal on a stack of ram so I have 320GB. This means rather than parallel plot, which I was doing first I tried via GUI in windows 10, then via PowerShell CLI plotter to 7 of the drives as 7 separate processes, plotting to each drive as temp and destination, then moving the plots off to the R515. This took around 16 hours for 7 plots so not a very impressive throughput. I tried adding in 6 more USB drives and plotting to all 13 at once, but this failed twice, so I am not sure if plotting directly to USB HDDs is worth it, but farming from them should be - yet to determine though. 13 at once doesn’t run the processor much over 40%, so more would be possible with a backplane or enclosure supporting another 10-20 SAS drives to plot to in parallel.
Swar plot manager helps to manage all of this, but with staggered parallel plots running 24/7, it’s a PITA if you need to reboot or maintain a machine as you will stop multiple plots mid-way through and waste them.
So…Now I am trying with madmax plotter - the fury road windows version to see how fast it can plot 1 plot at a time throwing everything at it (though I’ve only tried one so far and it didn’t max out my CPU), plotting to partially ramdrive, though I am also going to try 100% to ramdrive. Even if this isn’t faster, the ram will not degrade like an nvme or ssd would so this is a big plus for me.
Update - plotting 1 K32 plot using Furyroad/Madmax using 120 GB ramdrive and SAS as temp drives took 10000 seconds (2.7hours) allocating 28 threads, though the processor was only above 50% (a little) during phase 1 and 3, so I think I could stagger two parallel processes maybe get 2 plots in 3.7 hours? I have enough RAM.
I also tried entirely ram drive and used 280GB ram with two temp folders on the ramdrive. It succeeded but took 12700 seconds, so there is an advantage to using two temp drives, it seems rather than one very fast one. Many people have been raid 0 striping two SAS drives together to get a bit more speed. I will try this too, if I give up on parallel plotting to 7+ drives and limit it to 2 in parallel, then raid 0 pairs of drives as temp 1’s will be better than 8 x single drives.
I will also try this direct to SAS also to see if it makes a difference as I am not totally convinced ramdrive is all that worth it. Maybe my RAM isn’t all that fast (DDR3) or well utilised.
I’ll just blog different permutations here.
Ramdrive is worth it. Direct to SAS it was 4 times slower for the first table. So I abandoned that.
Now trying stagger using ramdrive for temp2 and SAS for temp1.
Tried 2 plots staggered, using Madmax/fury road 0.0.4.
Second one began after phase 1 completed on first one - 3000 seconds.
First plot finished in 13394 sec (3.7 hours).
Second plot took 14000sec (3.9 hours)
So I could make 12 plots per day with this software, with fewer disks spinning, and the ability to interrupt the system some way through.
I am wondering if my slow(ish) ram is the issue and why I cannot get the CPU to really max out.