Luminous Landscape Forum

Raw & Post Processing, Printing => Digital Image Processing => Topic started by: rabates on September 02, 2006, 06:11:32 pm

Title: 15 K drive
Post by: rabates on September 02, 2006, 06:11:32 pm
I noticed that Maxtor has a drive spinning at 15 K. If used as a scratch drive would it speed PS up a little ? Thought it might help video editing also.
Title: 15 K drive
Post by: tived on September 03, 2006, 06:37:51 am
Most brands have 15k drives but only SCSI, fiber channel and SAS

and yes, they would be very good for a scratch disk, but I would also have my OS disk being a 15k.

However, you are paying a premium for that last 3-5%, but 3-5% improvements in all the bottlenecks helps

I currently have a setup like this, with OS, scratch and windows pagefile all on seperate 15k disks and data stored on 10k 300Gb disks all SCSI U320 havent moved to SAS yet.  

Henrik
Title: 15 K drive
Post by: 32BT on September 03, 2006, 09:52:19 am
Quote
However, you are paying a premium for that last 3-5%, but 3-5% improvements in all the bottlenecks helps


I wonder about the relative merrit of 15k rotation vs 7.2k striped raid...
Title: 15 K drive
Post by: jecxz on September 03, 2006, 08:52:54 pm
Quote
I wonder about the relative merrit of 15k rotation vs 7.2k striped raid...
[a href=\"index.php?act=findpost&pid=75364\"][{POST_SNAPBACK}][/a]

I use 15K RPM hard drives for my CS2 scratch disk. In fact, I use 3 15K RPM drives in a RAID 3 setup for the scratch alone. There is a major speed boost with the faster hard drives over 7200 RPM, but I have never done a RAID with 7200 RPM drives so I would not know.

Check out 10K RPM SATA drives, they are very fast too.
Title: 15 K drive
Post by: tived on September 05, 2006, 10:32:46 am
Quote
I wonder about the relative merrit of 15k rotation vs 7.2k striped raid...
[a href=\"index.php?act=findpost&pid=75364\"][{POST_SNAPBACK}][/a]

Well, when you take cost into the equation, it becomes completely stupid ;-) but for reason, I still like the idea of 15k drives.

Also, currently the 15k drives are server/workstation disks and are made to run 24/7/365 and therefore are less likely to fail on you (but shit do happen!) so mirrow them

Henrik
Title: 15 K drive
Post by: Andrew Larkin on September 05, 2006, 06:01:28 pm
I spent some time yesterday researching current drive technology and came up with some unexpected (for me) results.

Just like the flash cards we buy for our digital cameras, sustained transfer rates are more likely to be of issue with hard drives used in photographic workstations.

Regular 7200rpm SATA disks seem to be able to deliver transfer rates of around 70 megabytes per second.

Seagate have a series of 7200rpm SATA drives that call "Nearline 35" that deliver up to around 95MB/s.

These seem roughly comparable to the Western Digital 10000rpm SATAs.  

Presumably this is done in the 7200's by increasing the number of platters/heads in the drive to increase the amount of data accessed on each rotation.  The NL35 series have some other reliability features that make them suitable for 24x7 operation.

The Serial Attached SCSI is an interesting technology that uses basically the same connectors and wiring as SATA but accesses higher data transfer rates.  The Seagate SAS drives are either 10k or 15k rpm.  The 15k drives provide sustained transfers of around 145MB/s.  Basically around double the transfer rates of a basic SATA 7200rpm corresponding to double the rotational speed.

What I don't understand is why these higher speed drives are continuing to be "reserved" for the specialised interfaces such as SAS when the SATA II interface can quite easily cope with it.

The SATA technology roadmap was original planned in three stages (from memory).  SATA giving 150MB/s, SATA II giving 300MB/s, and SATA III giving 600MB/s.

The other thing to consider is the bottlenecks within the controller-to-host interface.  I haven't fully figured out what is happening at this level.

The observation I have is that the breed of Serial Attached SCSI controller boards seem to be headed for PCI express but in the x16 format (as used for video cards).  I haven't come across any motherboards yet with more than two x16 slots (generally intended for dual video cards).

Andrew
Title: 15 K drive
Post by: giles on September 06, 2006, 05:24:28 am
Quote
I use 15K RPM hard drives for my CS2 scratch disk. In fact, I use 3 15K RPM drives in a RAID 3 setup for the scratch alone. There is a major speed boost with the faster hard drives over 7200 RPM, but I have never done a RAID with 7200 RPM drives so I would not know.

How noisy are they?  I don't like slow computers, but I don't like noisy ones either, and prefer not quite leading edge performance if it quietens things down a lot.  Of course I don't have volumes of shots to process in as short a time as possible, either.

I want to go back to a fanless, diskless desktop with remote storage.

Giles
Title: 15 K drive
Post by: jecxz on September 06, 2006, 09:00:30 am
Quote
How noisy are they?  I don't like slow computers, but I don't like noisy ones either, and prefer not quite leading edge performance if it quietens things down a lot.  Of course I don't have volumes of shots to process in as short a time as possible, either.

I want to go back to a fanless, diskless desktop with remote storage.

Giles
[a href=\"index.php?act=findpost&pid=75660\"][{POST_SNAPBACK}][/a]

The box is on the floor and they are not noisy at all, actually, silent. The CPU fan is louder. There are a lot of great remote storage solutions out there. Good luck.

dG
Title: 15 K drive
Post by: tived on September 06, 2006, 10:22:31 pm
Quote
The other thing to consider is the bottlenecks within the controller-to-host interface.  I haven't fully figured out what is happening at this level.

The observation I have is that the breed of Serial Attached SCSI controller boards seem to be headed for PCI express but in the x16 format (as used for video cards).  I haven't come across any motherboards yet with more than two x16 slots (generally intended for dual video cards).

Andrew
[a href=\"index.php?act=findpost&pid=75613\"][{POST_SNAPBACK}][/a]

Hi Andrew,

luckly we don't need dual graphics cards to run PS, as it does not take advantage of this technology. You could also buy a workstation mainboard and have PCI-X which i thought was faster but I could be wrong.


Henrik