GPU plot generator v4.1.1 (Win/Linux)

cryo

I changed the build system, so the only files required are the .exe and the [kernel] folder.
If it doesn't launch due to missing DLLs, install the Microsoft C++ 2015 redistribuables.

GabryRox

@cryo thank for the info. I just started a small 500GB plot using 4.1.1 direct mode and it launched fine after I installed the C++ package. However, I wanted to sanity check the write speed as it seems very low. I am only getting about 8-12 MB/sec in direct mode, compared to 80-120 MB/sec using the buffer mode from a previous version. Certainly I expected this to be somewhat slower since it writes plots already optimized, but is 10X slower reasonable? Or maybe I have set something wrong?

I used the same devices.txt setting (0_0_4096_128_8192) as with buffer mode and the same 20000 value in my .bat to use ~5GB of CPU memory. Any tips would be appreciated.

GabryRox

hmmm, and now it dropped down to 2-3MB/s, which means it will never finish at that rate. Been stuck there for more than 10 minutes so there must be something wrong.

haitch

@GabryRox In direct mode there is a long delay as it builds the empty file before filling it in - just wait, it'll get faster. As long as it's not an SMR drive .....

GabryRox

thanks @haitch - but this has been going almost 3 hours now, hovering between 2-7 MB/s most of the time, with an ETA for completing a measly 500GB plot in about 28 hours! I had to look up what an SMR drive is, and unfortunately, I probably do fall into the category as most of my drives are 5TB Seagate Expansion or Backup+Hub external HDDs.

Does this mean I am pretty much hosed trying to write in direct mode with these? At this rate, it would take 2 weeks to direct-plot a single 5TB drive lol.

BeholdMiNuggets

@cryo said in GPU plot generator v4.1.1 (Win/Linux):

I updated the GPU plot generator (v4.1.1). It now comes with file pre-allocation when launched with admin rights, which greatly speed things up in terms of IO operations.

Thanks for your update to /GPU Plot Generartor.

Running in Windows10 /Admin mode. (Latest Visual-Studio version installed). But getting an Error message: "[ERROR] bad allocation". The Plot size is only about ⅓ of the HDD. The same Plot works Ok (but slowly) with CPU plotters.

What causes this error message, and how can it be resolved?
Merci.

haitch

@GabryRox It's about two weeks for an 8TB drive, a 5TB will be about 10 days. You have a couple of options - plot in buffer mode - fast plot, slower mining, or plot to a PMR drive then copy to the SMR drive. If you're plotting a lot of drives - get an SSD, direct plot to that then move the plot to an SMR - rinse and repeat.

GabryRox

thanks @haitch - I actually have an empty 500GB Samsung EVO 830 in my newly built PC so I will try writing direct mode to that in maybe 400GB plots, then start copying those over to my SMR drives. that will end up making about 11 plots (not ideal i know) on the 5TB drives but what I've seen with my current 6-7 plotted drives is that my 1 drive with 13 small optimized plots reads 40-50% faster than my other drives with say 1-3 large, non-optimized plots, so it will still be worth it I think. Thanks again for the tip.

haitch

@GabryRox That will work out very well. Love those Samsungs almost as much as the Intel NVMe's.

GabryRox

@haitch Yup! This method may take a bit more baby-sitting but it will be soooo much faster! I am writing 400GB direct mode plots to that SSD in about 1 hour flat, then another 45 minutes or so to copy to the Seagate HDD. Even at 2 hours per file, that's only about 22 hours to almost fill a 5TB HDD vs 10 days the other way. Granted, i can't monitor this during sleep but since I work from home and already sit by this PC 10-12 hours a day, I can get a 5TB drive done easily in 2 days. Thanks again for this tip, really appreciate it!

tco42

@GabryRox you could write a little script that generates a file, then moves it to the hdd, writes the next file...

i think something like this could work:
gpuPlotGenerator generate direct <file>
move /y <file> <folder_on_hdd>
gpuPlotGenerator generate direct <file2>
move /y <file2> <folder_on_hdd>

cryo

@GabryRox With the buffer strategy the bottleneck part is the computing power, to some extent. However, for the direct strategy it's the IO bandwidth.
There are two solutions to efficiently use the direct strategy:

Plot to a faster disk (a SSD is the best choice), then copy the resulting files to a slower disk.
Plot multiple disks at once, up to your computing power (based on your observations you could easily plot to 10 drives at the same time with one single GPU and fill them in the same amount of time).

@haitch The long delay is gone with the new version when you launch it with admin rights (4.1+). Still, it takes time to write each plot.

@BeholdMiNuggets The bad alloc error is a RAM issue. The [staggerSize] in the direct mode is used to determine the amount of RAM used by the process. Example:

# Will generate an optimized plots file named [123456_0_1000000_1000000] (250GB) using 250MB of RAM.
./gpuPlotGenerator generate direct 123456_0_1000000_1000

BeholdMiNuggets

@cryo said in GPU plot generator v4.1.1 (Win/Linux):

@BeholdMiNuggets The bad alloc error is a RAM issue. The [staggerSize] in the direct mode is used to determine the amount of RAM used by the process. Example:
# Will generate an optimized plots file named [123456_0_1000000_1000000] (250GB) using 250MB of RAM.
./gpuPlotGenerator generate direct 123456_0_1000000_1000

Thanks Cyro (& others). - Any chance you give us another, practical /eg - for optimised (gpu) plots?
~ Don't see a ReadMe file in the current version of the GPU plotter, so referencing previous editions.

Eg.(just a random example!).
For an Nvidia Gtx-1080Ti GPU (aka Gtx-1090), with 11Gb of Gram /frame-buffer. On a Pc with a Total of 16Gb of RAM. And 2x 8Tb HDDs (say). ***

What could /should the [ devices.txt ] file contain?
And what would the process Command Line be?

Much appreciated, /B.M'Nugs.

cryo

@BeholdMiNuggets The README.md file is available in the repository. I've forgotten to include it in the binary releases, I corrected this for the v4.1.1.

About your example:

The GPU RAM buffer must be paired with a CPU RAM buffer. Also, another buffer needs to be created for each output file to store the staggerSize reordered plots.
As you want to plot in direct mode, the staggerSize doesn't have so much impact. It just needs to evenly divide the GRAM to free the graphic card in time to generate the nonces in parallel.
So let's say 8GB GRAM and 2x2GB RAM, for a total of 14GB RAM if you count the paired buffers.
8GB = 32768 plots
2GB = 8192 plots
7.9TB = 33046528 plots

The devices.txt file should contain:

<PLATFORM> <DEVICE> 32768 <LOCAL_WORK_SIZE> <HASHES_NUMBER>

With:

PLATFORM/DEVICE: The platform/device couple of your GTX1090Ti, as provided by the listPlatforms and listDevices commands, or by using the setup command.
LOCAL_WORK_SIZE: A GTX1080Ti posseses 3584 computing units. You can try 2048 for this parameter. If it is rejected by the card, divide by two, and so on (1024, 512, 256).
HASHES_NUMBER: 4096. If your screens blinks or you experience display driver crashes, use a small number, like 4.

The command line will be:

./gpuPlotGenerator generate direct <DRIVE1>:/<ADDRESS>_0_33046528_8192 <DRIVE2>:/<ADDRESS>_33046528_33046528_8192

With:

ADDRESS: The numerical value of your Burst address.

As discussed previously, depending on your disks, it may be better to plot on SSDs or to more disks at the same time to enhance the overall throughput.

BeholdMiNuggets

@cryo said in GPU plot generator v4.1.1 (Win/Linux):

The README.md file is available in the [repository].
About your example: ...

Cyro - thanks for the link, and your detailed response /example ~ Will give it a shot later today. Your efforts much appreciated. /B.M'Nugs.

cryo

@BeholdMiNuggets Sorry, I forgot the fact that the GPU buffer will be partially filled the whole time, thus the disks won't be able to write in parallel. It would be best for you to have GRAM=staggerSize.
Thus : 4GB GRAM, 2*4GB RAM, for a total of 12GB RAM if you count the paired buffers.
Just change the globalWorkSize to 16384 and the staggerSize to 16384.

BeholdMiNuggets

@cryo said in GPU plot generator v4.1.1 (Win/Linux):

... the GPU buffer will be partially filled the whole time, thus the disks won't be able to write in parallel. It would be best for you to have GRAM=staggerSize.
Thus : 4GB GRAM, 2*4GB RAM, for a total of 12GB RAM if you count the paired buffers.
Just change the globalWorkSize to 16384 and the staggerSize to 16384.

Tks.
So, you only need ~2Gb of System /CPU Ram - allocated (per GPU)?

cryo

@BeholdMiNuggets No, each GPU needs 4GB (x1 in this example), and each plots file needs 4GB too (x2 in this example), for a total of 12GB RAM.

BeholdMiNuggets

@cryo said in GPU plot generator v4.1.1 (Win/Linux):

...
7.9TB = 33046528 plots

Sadly, most "8Tb" HDDs only sport about 7.27 /Tb* of useable capacity! Which comes to ~ 30,493,248 Nonces (with a small degree of head-room).

The code GitHub repository (readme) reference states: "Tweaks: When using multiple devices, make sure they have nearly the same performance." Does this mean that 2x GPUs can be used (in combination), to speed up the process? For example, for 2x GTX-1080Ti/1090 GPUs (under Windows), the plot [devices.txt] file might read:
2 0 16384 4096 2048
2 1 16384 4096 2048

And the resulting Command Line (administrator) might look like this:
/gpuPlotGenerator generate direct
P:/plots/userburstid_200000000_30493248_16384
Q:/plots/userburstid_300000000_30493248_16384

Does that make sense?
Thanks.

cryo

@BeholdMiNuggets Yes, that's the spirit. But the processing power of your card is far quicker than your IO throughput in direct mode. The bottleneck part is the plots writing and your GPU is already waiting most of the time. So adding another one won't help.
In buffer mode that would help because the writing operation is quick, and the plot generation becomes the bottleneck part. But the resulting files won't be optimized.