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LinuxVillage welcome => The bistro! => Discussion démarrée par: Seditio le 13 décembre 2013 à 00:13:41

Titre: Linux distro loading times.
Posté par: Seditio le 13 décembre 2013 à 00:13:41
Okay so I just recently got my new Kingston Solid State Drives, and they're currently loaded in a RAID0 layout (mostly for my gaming) and paired up with my 500Gb Western Digital HDD and 1TB Samsung HDD.

Now I've been running Linux on my Samsung disk for over 2 years, time to have some fun with SSDs :3

Does anyone want to see how fast their distro loads on these beasts? :p

Config:
CPU: Intel i5-2500k @ 4.7Ghz watercooled.
GPU: Sapphire R9 270X
Motherboard: ASUS Sabertooth P67
RAM: 4x2GB Crucial Ballistix 1333Mhz
SSD: 2x Kingston HyperX 3K (RAID0)
Titre: Re : Linux distro loading times.
Posté par: mimas le 13 décembre 2013 à 09:42:25
Hi

> they're currently loaded in a RAID0

What's the point? This RAID level is made to speed up devices, ig. two 5400 RPM Hard-drives make a supa-hard-drive at no cost in a RAID 0 array. You won't speed up SSDs a lot, it's memory (the major bottleneck for memory is the data bus). You have paid the MB/s at the higher price. Moreover, benchmarks show a higher latency with RAID 0 array.

This level is not fault-tolerant, you lose every data on the array if one of your drive is going crazy (yeah buggy SSD firmware!!).

Titre: Re : Linux distro loading times.
Posté par: melodie le 13 décembre 2013 à 13:30:20
Hi Sedition, hi mimas,

If I understand well what mimas says, Seditio looses on one side what he gains on the other? And this would be with an added risk of data lost?
Titre: Re : Linux distro loading times.
Posté par: mimas le 13 décembre 2013 à 16:21:30
> Seditio looses on one side what he gains on the other?

Memory is fast (we count in nanoseconds). So it makes no difference for a human being because it is out of human perception range. Hard drives are mechanicals and slow; their mechanical delays are within or close to human perception range (> 10 ms, from POOFA study*)

*Pulled Out Of My Ass
Titre: Re : Linux distro loading times.
Posté par: Seditio le 13 décembre 2013 à 18:37:14
I'm currently toying with the RAID as it does boost read speed from 480MB/s to 970MB/s, so the effect here is clear, as for latency time, I see nothing.
Titre: Re : Linux distro loading times.
Posté par: mimas le 13 décembre 2013 à 20:07:45
Let's get numbers!

For an ISO of 780 MB:
- Fast hard drive, loading time = 780 / 150 = 5.2 s
- Single SSD, loading time = 780 / 480 = 1.62 s
- Dual SSD RAID 0, copying time = 780 / 970 = 0.8 s

Nice but nobody copies ISO files all day long. So let's do it for an average 2.5 MB files

- Fast hard drive, 2.5 / 150 = 0.016 s
- Single SSD, 2.5 / 480 = 0.005 s
- Dual SSD RAID 0, 2.5 / 970 = 0.002 s

Is there a difference between a file loading in 0.005 second and a file loading in 0.002 second? It could be a difference in a huge network but not in desktop computer, even if you're a serious gamer.

Let's do charts because everybody loves charts.

(http://pix.toile-libre.org/upload/original/1386967968.png)