On 5/3/2019 11:46 PM, Paul wrote:
RayLopez99 wrote:
On Tuesday, April 30, 2019 at 6:18:47 PM UTC-4, Paul wrote:
Lynn McGuire wrote:
"Backblaze Hard Drive Stats Q1 2019"
Â*Â* https://www.backblaze.com/blog/backb...stats-q1-2019/

"As of March 31, 2019, Backblaze had 106,238 spinning hard drives in
our
://microless.com/cdn/products/f18e4964c96110fb07f12102f30fdde8-hi.jpg

Based on design, it's a helium drive. If it was air-filled,
there would be a breather hole. Those platters would also be
"thinner that regular platters"

The more platters = more trouble.

Â*Â*Â* Paul

What is the advantage of helium, other than less air resistance and I
guess less heat transfer?

RL

It has reduced air resistance.

And heat transfer is improved.

Â*Â* "The thermal conductivity of gases.

Â*Â*Â* The value of thermal conductivity for most gases and vapors
Â*Â*Â* range between 0.01 and 0.03 W/mK at room temperature. Notable
Â*Â*Â* exceptions are Helium (0.15) and Hydrogen (0.18)"

I don't think there is any plan to switch to Hydrogen.

If you get a datasheet for drives, you can kinda tell which
drives have Helium, just from the operating power numbers.

Â*Â*Â*Â*Â*Â*Â* ReadsÂ* MTBF

Â* 12TBÂ* 7.0WÂ*Â* 2,500,000
Â* 10TBÂ* 7.1WÂ*Â* 2,500,000
Â*Â* 8TBÂ* 7.1WÂ*Â* 2,500,000
Â* ----Â* ----Â*Â* ---------
Â*Â* 6TBÂ* 9.3WÂ*Â* 2,000,000
Â*Â* 4TBÂ* 9.0WÂ*Â* 2,000,000
Â*Â* 2TBÂ* 7.4WÂ*Â* 2,000,000
Â*Â* 1TBÂ* 7.4WÂ*Â* 2,000,000

I've not read any descriptions of what happens
when the drive runs out of Helium. It's guaranteed to
have Helium for five years. I presume the flying height
changes.

Â*Â* Paul

Sure, we could use hydrogen for hard drive cooling. Older power plant
generators use pure hydrogen gas for cooling. With a very involved
purging and oil based sealing process. Of course, hydrogen filled hard
drives could bring back excitement to computing when they have a
containment breach.

Lynn