Optional CPU upgrades for Z420

[amil56]

Thanks DGroves,

The program is Chia plotter, it creates 106GB files which later on being moved to a slower disk. The creation of 1 plot can take between 6-12 hours. When paralleling it can take even more.

When I check the disk performance in windows 10 I see that its very inconsistent, reaching 300-400 MB/s quite rarely. I thought that a DC SSD can give me better performance. Although the m.2 I'm using is rated 3000MB/s it doesn't even come close.

In case I'll buy the Seagate ssd which is rated 850MB/s and in will give me even constantly 50% of its rated speed I'll be a happy camper.

Am I being too optimistic? Will reaching constant high speeds are not achievable using these SSDs?

Is the only thing the DC rated give you is better endurence?

Thanks

[DGroves]

please understand that statements like  "up to 3000MB/s" is not a a real number, it's market speak for a theoretical max speed that in real life is not a sustainable number

consumer drives using TLC/QLC based nand have a onboard pseudo "SLC" cache/buffer that when exceeded will cause the actual write speed of the ssd to be not that much faster than a 10/15k rpm mechanical  drive

prosumer ssd's and enterprise/datacenter ssd's are MLC based and have no SLC cache as mlc r/w speeds are fast enough to not require a cache, and for "chia" you absolutely need a prosumer/datacenter based MLC ssd

here's a brief description on these subjects:

https://www.atpinc.com/blog/what-is-SLC-cache-difference-between-Dynamic-Static-SLC-cache

https://www.storagereview.com/review/manage-multiple-chia-plotters-farmers-and-harvesters

https://www.mydigitaldiscount.com/everything-you-need-to-know-about-slc-mlc-and-tlc-nand-flash.html

[amil56]

Thanks DGroves, that's exactly what I meant. Both of the ssd I mentioned are MLC this is why I assumed they will give me better performance. The SK hynix is rated up to 445MB/s the Seagate is rated up to 850MB/s.

I know a lot of chia plotters use this kind of disks.

Let's say I want to use 2 or 3 of the Seagate SAS SSDs. I don't need them to work as raid (unless you'll advise it's faster) - do you have a recommended SAS controller? Which cables should I use? 

[BambiBoomZ]

Amil56,

The suggestion to use enterprise M.2 is with regard to the read/write endurance rather than concentrating only on high performance.  Chia is very write intensive.  A single plot is 100+ GB but to achieve it creates ~1.3TB writes / plot.  A typical farming system may run 50+TB writes per month and that may equal ~30% of the total write endurance of a consumer grade drive; apparently a low end drive might last only 6 or 8 weeks. The endurance is longer by the capacity of the drive and 2TB is talked about as  a kind of  standard. A Viper VPNN100 2TB has a write endurance of 3,100TB- which = more than 1.5 years duration.

As Chia farming is "proof of space" where Bitcoin is "proof of processing", the storage HDDs are best when quite large.

BambiBoomZ

[amil56]

Thanks BambiBoomZ,

I'm aware of the endurance issue. The thing is that I can't get the pace I was expecting from my z420 plotter machine. I'm less concerned with the time it takes me to create one plot rather than being able to take advantage of the high core CPU and run many plotting instances side by side. This is why I thought have the enterprise SSD will handle better the concurrent IO load.

I did some more research and seems I should have one of these:

SAS Controller which already comes with a cable allow me to connect 4 SAS SSDs.

Again, I can find this model in a pretty good price (used):

Seagate SAS SSD 

The exact model is the st960fm0013 (rated up to 1900/850 r/w MB/s)

Will the combination of the two products I've just linked work on my Z420? The plan is connect 3 of those SSDs to a total of 3TB raid0. I guess I should get a decent stable performance with them which will probably allow me to run several processes in parallel.

The Other option is to purchase a new SK Hynix 2TB SSD (SATA) which I know will work but probably not give me the same performance.