Why don't 15K Velociraptors Exist?

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Zargon

Lifer
Nov 3, 2009
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complete waste for just "storage" if anything I specifically search for slower spinning drives for my "storage" needs

I agree with Zap though, there's a place for a 600GB 10KRPM VelociRaptor @ $130, it would be a pretty perfect size for apps and games that don't fit on a SSD, but time for that is running out as the next gen of SSD should halve the cost per GB and bring performance improvements making it even harder to justify investing anything into disc based drives for performance needs

yeah it would make a great STEAM drive. but the current gen ones are way too pricey

the last gen 300 gb for about 150 would be OK, but its not *that* fast compared to regular higher speed 7200 rpm's drive AFAIK
 

Voo

Golden Member
Feb 27, 2009
1,684
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but i guess if you are not building anything important, like something that might kill people, yes maybe "centrifugal" is good enough.
Uh yeah, I mean the stuff built based on classical mechanic is negligible, handful toys. If you can't refute the nice existing mathematical equations (for rotating reference frames! We're not talking inertial frames here), it's pretty useless to continue this discussion.

It seems the big problem here is that it's a inertial force, but hey the same is true for the coriolis force - would you like to dispute that one as well?
 

Emulex

Diamond Member
Jan 28, 2001
9,759
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you guys realize the platter size of a 15K 3.5" drive is about the same as the 10K 2.5".

10K 600gb 2.5" SFF are mainstream now which makes me wonder when they will bump 3.5" 15K up to 900GB or 1.2TB ;)
 

taltamir

Lifer
Mar 21, 2004
13,576
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obviously you don't understand the significance of that picture.

that is a jet engine that suffered a rotor burst.

the shredded yellow stuff is a kevlar jacket that catches outward flying shrapnel, which would not be necessary if "centrifugal" force actually existed.

You are utterly wrong. The yellow stuff was torn by outward flying shrapnel caused by INERTIA, NOT by centrifugal force.

Nocentrifugal.png
 

OS

Lifer
Oct 11, 1999
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You are utterly wrong. The yellow stuff was torn by outward flying shrapnel caused by INERTIA, NOT by centrifugal force.

lol thanks, that's what i was saying, it's NOT centrifugal force..
 

taltamir

Lifer
Mar 21, 2004
13,576
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lol thanks, that's what i was saying, it's NOT centrifugal force..

wait... arrg. Ok I misread what you said but not its even more confusing.
Why WOULDN'T you have shrapnel if centrifugal force actually existed?

If centrifugal force existed then the ball in the picture I drew will fly to the right instead of straight ahead... but regardless if flying straight ahead or to the right it will still produce shrapnel.
 

OS

Lifer
Oct 11, 1999
15,581
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because if there were centrifugal force the shrapnel or the ball would continue along the curved path it was already moving, instead of outward/tangential to the curve.
 

Voo

Golden Member
Feb 27, 2009
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because if there were centrifugal force the shrapnel or the ball would continue along the curved path it was already moving, instead of outward/tangential to the curve.
I still don't see how the example makes any sense, since the centrifugal force is always directed outwards away from the center - which is exactly what you're describing. A centrifgue really isn't anything out of the extraordinary or is it?
 
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taltamir

Lifer
Mar 21, 2004
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because if there were centrifugal force the shrapnel or the ball would continue along the curved path it was already moving, instead of outward/tangential to the curve.

Ah, I see now... you are confusing centrifugal and centripetal.

Nocentrifugal.png


-In reality, the ball will fly in a straight line as soon as I let go of it.
-If there was centrifugal force (force FROM the center OUTWARDS) then the ball will fly to the RIGHT.
-As long as there is a centripetal force (force TOWARDS the center) the ball will continue along the curved path in which it was already moving. In this case the "centripetal force" is tension force on the string caused by me. The moment I "let go" the centripetal force (tension force in this case) I am exerting stops and the ball flies forward due to inertia.
 
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OS

Lifer
Oct 11, 1999
15,581
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Ah, I see now... you are confusing centrifugal and centripetal.

Nocentrifugal.png


-In reality, the ball will fly in a straight line as soon as I let go of it.
-If there was centrifugal force (force FROM the center OUTWARDS) then the ball will fly to the RIGHT.
-As long as there is a centripetal force (force TOWARDS the center) the ball will continue along the curved path in which it was already moving. In this case the "centripetal force" is tension force on the string caused by me. The moment I "let go" the centripetal force (tension force in this case) I am exerting stops and the ball flies forward due to inertia.


excuse me you are right, my description and example are wrong, but the end result is still there is no centrifugal force in it of itself, only centripetal force.
 

taltamir

Lifer
Mar 21, 2004
13,576
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excuse me you are right
It happens, I myself managed to misread what you said and get one of my previous posts wrong.

my description and example are wrong, but the end result is still there is no centrifugal force in it of itself, only centripetal force.
wait... if we all agreed than what are we arguing about? :p
 

Zap

Elite Member
Oct 13, 1999
22,377
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81
yeah it would make a great STEAM drive. but the current gen ones are way too pricey

the last gen 300 gb for about 150 would be OK, but its not *that* fast compared to regular higher speed 7200 rpm's drive AFAIK

Late last year Newegg had the 300GB VelociRaptors on sale for $99.

I've got an SSD for Windows and WoW. Steam, BFBC2, MW2, SC2 are all on the 300GB VR (purchased when they came out a couple years ago).
 

Emulex

Diamond Member
Jan 28, 2001
9,759
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too bad you need 12V - i wanted to put the 300meg velociraptor in a macbook ;)
 

Voo

Golden Member
Feb 27, 2009
1,684
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excuse me you are right, my description and example are wrong, but the end result is still there is no centrifugal force in it of itself, only centripetal force.
Sigh, ok I give up - the whole INERTIAL force part somehow seems to get ignored the whole time. Yeah as soon as we give up on the whole rotating reference frame stuff, it somehow doesn't seem to work - what a strange thing that stuff only works when the premisses are fulfilled.

Whatever your engineering degrees are, I somehow doubt you had lots of mechanics classes..
 

Zap

Elite Member
Oct 13, 1999
22,377
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81
too bad you need 12V - i wanted to put the 300meg velociraptor in a macbook ;)

The drive is also thicker than a normal notebook drive, so often it won't physically fit a notebook even if you take it out of the heatsink or buy the actual 2.5" version.

Hmmm, I do however know that I can get one into my Clevo M980NU beast. :hmm:
 

Emulex

Diamond Member
Jan 28, 2001
9,759
1
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yeah i have the enterprise version with TLER they don't come with heatsinks since those don't fit in 2.5" SFF hot swap cages.

I bet that mofo would vibrate like crazy? i wonder if anyone ever made a 15K or 10K laptop - that would trip some folks out.
 

Fallen Kell

Diamond Member
Oct 9, 1999
6,229
543
126
Why? Spinning a spindle at 15k means some serious centrifugal force, so the spindle better be of small in diameter (as is the case for Raptors). And small is lacking in storage space.

600GB 15k SAS is current "top", AFAIK. You can connect those 3TB SATA backup volumes to a SAS controller too. ;)

You do know that 15k rpm hard drives have been around for 10+ years don't you?

Heck, here is a review from 2003 on the latest generations of 15k RPM drives, and you should note the Cheetah 15K.3 (which worked the same way then as the 7200.10, 7200.11, 7200.12 etc., do now, meaning there was a 15K.2 and a 15K before it):
http://www.xbitlabs.com/articles/storage/display/15k-roundup.html
 

Emulex

Diamond Member
Jan 28, 2001
9,759
1
71
yup i've been using them for that long. used to be those 15K drives would overheat like a mofo without mad extra cooling fans.
 

mv2devnull

Golden Member
Apr 13, 2010
1,532
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Hitachi does have a 4U rack mounted High Density Storage Extension Tray for its AMS 2000 (SAN) series. One does "push down" drives to it, because the SAS backplane is at the bottom. (They are not the only ones with that design.) There are 48 drive-slots in the tray, but the specs limit the number of (15k) SAS disks to 38, due to the cooling requirements. Therefore, the heat is still with the 15k.
 

Baasha

Golden Member
Jan 4, 2010
1,989
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I have run a system with 2 SAS 15k drives in RAID 0 and it sounded like 2 cats killing each other under heavy I/O loads, not a good thing for home use. And the access times are indeed around 3-5ms.

I have 2 15k SAS drives in RAID0 and I completely disagree regarding the noise. The SAS drives serve as my Games/Programs drive and they are absolutely perfect. The 2 SSDs in RAID0 are my OS drive and that too is awesome. Can't wait for the new generation SSDs!
 

Rifter

Lifer
Oct 9, 1999
11,522
751
126
I have 2 15k SAS drives in RAID0 and I completely disagree regarding the noise. The SAS drives serve as my Games/Programs drive and they are absolutely perfect. The 2 SSDs in RAID0 are my OS drive and that too is awesome. Can't wait for the new generation SSDs!

it was 4 years ago, they were Hitachi HUS151473VLS300 drives and they were very loud. perhaps yours are newer and quieter.
 

LokutusofBorg

Golden Member
Mar 20, 2001
1,065
0
76
You do know that 15k rpm hard drives have been around for 10+ years don't you?

Heck, here is a review from 2003 on the latest generations of 15k RPM drives, and you should note the Cheetah 15K.3 (which worked the same way then as the 7200.10, 7200.11, 7200.12 etc., do now, meaning there was a 15K.2 and a 15K before it):
http://www.xbitlabs.com/articles/storage/display/15k-roundup.html
Every picture I've seen of the internals of a 15k drive show smaller platters. So even though the overall drive form factor is 3.5" the actual platters are the same size as 2.5" drives. I'm not sure that the outer cylinders on a 3.5" platter would be readable by the head when they're spinning at 15k. The sectors would have to be spread way out.

Compare this picture to this picture and you'll see what I mean.

EDIT: Emulex already said this above, but here are some pretty pictures to back up the point.
 
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