VRaptor SATA2.0 vs SATA3.0

dillonjerry

So I'm building a new workstation right now, and by no means is this the first time. The board is an ASUS P8P67, and the CPU is an Intel 2500k. I plan on running the OS off of a RAID0 array. I image my OS partition on a regular basis, so I'm not worried about being in RAID0. My question is this. I can either go with two WD 74 Gb VelociRaptors or two Segate 500 Gb drives. Normally this would be a no brainer, I'd go with the 10k drives. But the WD drives are ATA/300, while the Segate drives are ATA/600. How will these two drives compare in performance? Does SATA 3.0 have as much an impact as a SATA 2.0 drive running at 10k RPM's?

This is a desktop workstation, I'm not concerned about gaming. Much more concerned with CAD and applications. Any thoughts?

Pengwuino

Check out the maximum burst read speeds for the hard drive. If it's lower than SATA2's 375MB/s capabilities, I wouldn't bother with SATA 3 worries. And I highly highly doubt it's even 150MB/s burst.

rcgldr

Sata 2 transfer rates exceed the streaming rates of any current hard drive.

The 10,000 rpm drives will have a faster average seek time. the streaming transfer rate might be better on the 7,200 rpm drives if those are based on newer tehcnology with sufficiently higher bit densities to compensate for the slower rotation rate.

There are also SSD (solid state) drives from 40GB to 600GB, but I'm not sure of the streaming rate versus the latest drives, probably the Seagate XT 2GB hard drives, with max rates over 100 mega-bytes per second.

You may be able to use a utlity to "destroke" (usually a mode select command) a hard drive, reducing it's capacity by only using the outer diameter (faster streaming rate).

dillonjerry

I've heard that there were ways to structure the data on the platters that would result in faster seek times. I was under the impression that the inner region was the fastest, but I could be wrong. I've never heard of being able to actually limit the locations on the platters where data is written to. What utility would you use to do this?

rcgldr

You'd have to contact the hard drive maker to see if a uitlity exists for a particular drive. I think that companies that buy a lot of drives for raid arrays are able to either order destroked drives (set up drive maker) or to get utilities to destroke (short stroke) the drives themselves.

dillonjerry

Wouldn't limiting the partition size be essentially the same thing? I mean, if is a 500GB drive, and you set up a partition that's only 100GB, wouldn't this be similar? The only difference being that maybe you wouldn't have control over where the data is being stored on the platters themselves?

Pengwuino

Solid state drives are hitting in excess of 300MB/s read speeds these days. WOOT.

rcgldr

You'd need to restrict the partition size so it only occupied the outer diameter of the first platter surface. Most current technology drives have 500GB to 600GB per platter (2 surfaces), so a 500GB current technology drive should be a single platter drive with 2 surfaces. You do need to check the specifications. I found that Best Buy is still selling older tech Seagate 7200.9 drives (current tech drives are 7200.12). I don't know what the capacity per platter is on the 7200.9 drives, but the bit density and streaming data rates are slower.

This document from Seagate mentions using mode select to destroke drives, but doesn't mention where to get the utlity that does this. I'm guessing that raid controllers (ones you plug into a PCI or PCI Express slot) come with software utilities to do this.

http://www.seagate.com/docs/pdf/en-G..._readiness.pdf

For a home user, since the first partition will end up on the outer diameter of the first surface, you can keep the first partition on each drive relatively small (100GB would use a bit less than 1/2 of the 250GB per surface).