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Ability to change where Genetica stores temporary files.


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#1 Nofew

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Posted 20 March 2013 - 07:08 AM

In a week or two I'm getting an SSD. They wear out quickly if excessive data is written to them. To prevent this from happening, I plan to keep a regular HDD installed along-side the SDD that'll house temporary files.

As it stands, Genetica stores its temporary files (which, for me, are huge) to C:\. I need to change this to another drive or I'll be replacing that SSD more often than I'd like.

Based on how I think it's working, I figure it'd be rather easy to change the variable it's using from "%SystemDrive%" to "%GenTemp%" or something along those lines, then add an entry under Edit > Preferences to change the contents of the variable. Perhaps it should be possible to select a specific folder rather than an entire drive..

#2 Silkrooster

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Posted 20 March 2013 - 09:06 PM

How on earth can an SSD wear out? I never heard such a thing. I don't mean to point out that you are wrong or right, its just I never heard of it. There is no moving parts, that has me a bit baffled.

#3 Nofew

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Posted 22 March 2013 - 05:10 PM

Easily. The fact there's no moving parts is the problem.

To store data, the SSD has an array of capacitors in it. Today there's three types of SDD's -- I forget the exact terms, but I'll start with the simplest. Basically, it works like DRAM that doesn't loose its charge after it looses power. If a cell is discharged it's a 0, charged is a 1. However, as the cells are written to, over time, they retain or leak voltage. After roughly 100,000 writes it becomes impossible to reliably tell if it's a 1 or 0 anymore. The problem is, these drives are very limited in capacity, usually only running up to about 60 gigabytes.

The next kind of SSD uses the same technology, but rather than binary logic, it has quad-logic. This quadruples the amount of storage space with the same amount of materials. A single cell that's fully empty reads as "00", quarter full reads "01", half is "10" and full is "11". Obviously, this makes it more sensitive to those shifts in voltage. To make the problem worse, it's impossible to partially discharge a cell accurately. As a result, any time any data is written to a cell, it must be completely discharged first. This inflates writes even more, and in the end causes each cell to only last about 3,000-5,000 writes.

The third kind of SSD uses 16 states of logic. The same problems follow, and it results in a drive that has roughly 1,000 writes per cell before it flops over.

To be clear, this means larger drives do last longer (assuming wear-leveling is used) -- That being said though, most drives made today are of the third kind. That means a 256 gigabyte drive can take roughly 256 terabytes of writes. At the rate Genetica uses it on my system, that drive would die in 12-18 months. (Keep in mind though that I'm rendering at 20480x20480. Most people won't run into as serious of a problem as me.)

To help get rid of some confusion, the drive can still be read from just fine without causing damage. It's only writes that are problematic. Also, after enough data has been written that things keep going wrong, the firmware enters a panic state and transforms the drive into a read-only medium. On top of that, provided the drive isn't written to more than its limit, it will actually last a very long time.

Edited by Nofew, 22 March 2013 - 05:25 PM.


#4 Allen 1

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Posted 22 March 2013 - 05:50 PM

If this is the case, then this technology very much needs to improve or something else needs to replace it entirely. It might be a good course of action that i am burning to blu-ray discs.

#5 Nofew

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Posted 22 March 2013 - 05:58 PM

The trick's to use two hard drives per system. Normally you have an SSD that holds your OS and programs and you write all your files to an HDD, as my current setup. (And just about everyone else's)

Like any technology, you can't just buy it and expect it to work without knowing how to treat it right. Just earlier today I had a laptop I was fixing sent to a client. When a friend of mine was explaining how to use it (I had to install Linux -- He doesn't have the money for a new hard drive and his keep breaking) he almost picked it up rather violently while it was booting. When he went to turn it off he went right for the power button rather than asking how to turn it off properly, and then almost shut the lid while it was turning off. (That would have tried putting it to sleep while it was going down) -- Now it's no surprise why he had three hard drive fail in less than a year. Through all this, he thought he was treating his laptop perfectly.

Regardless, the required change is dead simple and should take less than a minute to complete. Even if this is the technology's fault, why not do it?


Allen1: I wouldn't do that if I were you, unless they're R's. RW's suffer from an even worse flaw and can only be written to a few hundred times. While it's on my mind, almost every thumbdrive out there is just a regular SSD with 16-state logic and a really slow controller. Don't use those either. Stick with HDD's if you need longevity.

Edited by Nofew, 22 March 2013 - 06:09 PM.


#6 Allen 1

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Posted 22 March 2013 - 08:41 PM

I think i wil be alright. :) Thank you for the concern.

#7 Atlas

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Posted 23 March 2013 - 06:54 PM

Click Edit > Preferences, and then in the dialog that pops up, edit the "Resource Library Location".

#8 Nofew

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Posted 15 April 2013 - 03:58 AM

Ah, thank you, that helps.

I'd still like it separated if possible, though. I won't nag on it much now that I know it can be changed, but I prefer loading my textures from my SSD for the increased speed. On top of that, I just don't like mounting my other internal HDD -- I like to keep it spun down as long as possible, and once I mount it Windows won't spin it down correctly until I reboot. So, basically, I want to set up my nodes in Genetica, and only when I'm /just/ about to hit "render", then mount the HDD.

Regardless, I'll be fine either way. It's just a little thing that'd make my life a few clicks easier.




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