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  #1  
Old 12-08-2000, 09:36 PM
Lee Blaske Lee Blaske is offline
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Default Re: Seagate Cheetah 15,000 rpm

Given the current G4 architecture, I don't know if drive speed is a limiting factor. I would think that PCI bus data throughput issues would negate any advantage of faster drives. Currently, we're instructed to set data transfer rates lower than what our PCI SCSI cards are capable of doing.

It would be nice to hear a Digi tech person weigh in on this, but I'm thinking you might actually be better off with cheaper, quieter, not-so-hot running 10 k drives.

Lee Blaske
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  #2  
Old 12-09-2000, 01:18 AM
rosindabow rosindabow is offline
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Default Seagate Cheetah 15,000 rpm

I have a 24 bit TDM system running off the new G4/500. I want to purchase 4 new 18gig seagate Cheetah drives. There are two types avaialble. One at 10,000 rpm and the other at 15,000 rpm. the seek time is quicker on the 15X drive as well as some other minor improvements. There's about a $100 difference and I want to know if there would be any noticeable performance difference between the two drives.

I'm also looking toward the future and wondering if these newer quicker seek times will mean anything in a year from now. Any ideas? Anyone bought these new Cheetahs?
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  #3  
Old 12-09-2000, 02:16 AM
JC925602 JC925602 is offline
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Default Re: Seagate Cheetah 15,000 rpm

Hi

fast, and fater drive are made for server and Pro Tools....

33MHz, 32 bit PCI = more than 2 000 000 persons asking for info on a server (someting like Bush or Gore...); no dispalay, no keyboard, no mouse... And no real time video, TDM,..

or 32 bits = 3 bytes
33 MHZ = 32 000 000 * 1 sec
so 33 000 000 * 32 Bits = ( + or - ) 100 Mbytes/sec...

...Seek time...

So faster drive = more edits on one drive, faster copy, and much more fragmentation before DAE say drive to slow.

but you will still get "PCI bus to... (360 SCSI???)

100$... better go for RAID, dual SCSI (built into ATTO card I think), better seek time.

JC
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  #4  
Old 12-09-2000, 05:00 PM
Gulliver Gulliver is offline
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Default Re: Seagate Cheetah 15,000 rpm

Audio doesn't need drive speed in through-put (megabytes per second), but in seek time. There are a large number of files (with audio) running at the same time. The drive needs to access a little bit of each at a time so that they can be put together. It's not like video where there is one stream. Seek time is everything.

RAID doesn't increase seek time, only through-put. The drive armatures within a RAID group should move in unison; thus similar seek time.

NOTE: On the ATTO card, you drop the sync rate to 20/10 and burst rate to 32, you are actually slowing the card down.

Get the fastest seek time you can afford.
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  #5  
Old 12-11-2000, 09:20 AM
Ron Galbraith Ron Galbraith is offline
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Default Re: Seagate Cheetah 15,000 rpm

Someone mentioned to go with the older quieter/cooler Cheetah, but I did a comparason to the 10K drive vs the 15k drive, and the 15k drive was much quieter, and much cooler. This was backed up in a magazine article, can't remember what magazine.
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  #6  
Old 12-11-2000, 10:56 PM
AMG AMG is offline
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Default Re: Seagate Cheetah 15,000 rpm

It is true that Seagate managed to produce faster spinning drives without an increase in heat and power consumption. Infostore magazine had a comparison recently or the 15k vs. the 10k. The performance increase was not as great as expected - altough this magazine is geared towards large server and high transactional users with SANs.

BTW, you can increase access time using a RAID configuration, contrary to what was posted here. But it depends on the type of RAID configuration. RAID 3 will lock the armature movements together to give you the greater throughput (with redundancy through the use of a parity drive), but RAID 5 is designed for higher transactions where the armatures are not locked together and the parity is spread among all the drives. There is a slight throughput penalty in RAID 5. Of course, I'm talking about hardware RAID configurations.
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Old 12-12-2000, 08:11 PM
rosindabow rosindabow is offline
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Default Re: Seagate Cheetah 15,000 rpm

Thanks for the input. After much consternation, I went with the 15X drives. I don't think that it will make much difference with 48K but I think when we start cutting at 96K the improvement will be noticeable. I called Seagate, checked with Digi (which by the way their answer was check the website), i called Atto and a host of other folks. This seemed to be the best answer. I'll let you know how they work when I get them up and running.
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  #8  
Old 12-12-2000, 09:47 PM
Gulliver Gulliver is offline
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Default Re: Seagate Cheetah 15,000 rpm

AMG - I respectfully disagree.

For audio, RAID level 0 would be used. It is a simple stripe of drives to speed them up. RAID level 3 and 5 are used for speed and redundancy, and are not as efficient as level 0, simply because they waist time on the perity data.

2 drives striped together (level 0) as one drive will have way slower access time than 2 drives running without RAID. This is because the independent drives have free armatures, free to move about the disk on their own. RAID forces armatures to lay the same data, or more data if there is parity involved.

If you have 2 drives, spread the tracks from your song between the two, like Digi recommends.

I will agree that there is some access time improvements for a RAID group versus one drive, but it is only due to the decreased work load of the multiple drives, as they have to lay less data each.
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  #9  
Old 12-13-2000, 08:02 AM
dave-G dave-G is offline
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Default Re: Seagate Cheetah 15,000 rpm

The Cheetah x-15's greater speed aside, it apparently uses a liquid suspension instead of bearings. This is in part why it runs cooler, quieter and longer. I'm getting a pair in a Rorke hot-swap enclosure. Noiiyce.

-dave G.
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