Velociraptors and storage capacity and misunderstandings, oh my!
I notice that you barely hear/see anyone talk about Western Digital Raptors anymore.
They're not as fast as SSD's don't you know!
Well wait a minute... Those of you who say that, what are you backing up to? Yeah, I thought so. Lowly 1, or 2, or so terabyte conventional drives that Raptors own in virtually every single benchmark. And how many of you even use a 5,400rpm drive for backup?
Raptors pretty much beat those drives up and take their lunch money.
So why the hate?
One of the biggest reasons for the hate I think, is the general misunderstanding that people have towards the 3Gb/s older interface as well as the newest 6Gb/s interface.
"Well the Velociraptor is nowhere near tapping that out!".
Well folks this is not true at ALL.
The confusion comes from gigabit, vs. gigabyte. A 6Gb/s interface is not 6 gigabyte, it's 6 gigabit per second. And folks, that's a really huge difference.
The maximum bandwidth for the 3Gb's interface is 300MB per second. That's it.
And the newest Velociraptor has burst cache reads of almost 500MB per second. Well above the 3Gb/s maximum speeds.
Even the 6Gb/s interface at 600MB per second, is already tapped out by ssd's (which is another story altogether). Remember, the number for each of these is the maximum theoretical speeds. There is overhead involved, which brings those numbers down a bit. Rendering the 3Gb/s interface not very optimal for the latest Velociraptor drive.
In fact, OCZ has recognized these limitations, which is why they've gone to the Revo drives with pci-express interface, so that they can pump upwards of a terabyte per second on some tests.
Now of course the pricing on the smaller Velociraptors is too close to that of ssd's to make it a reasonable purchase. But once you get to the 500gb and 1tb Velociraptors, it's game on.
In fact, i'd venture to say that for most normal people who don't have tb's of movies on their backup drives, a 1tb Velociraptor drive is simply unmatchable by any other method of desktop storage for anywhere near the same price.
Ive been using my 600GB Velociraptor for a few years now.
I wouldnt go without it.
Looking at the 1 tb now too .
I personally don't have a hate on for the raptor drives, my issue with them is usually price point. Last time I bought spindle drives for myself was right before the price hikes. You could buy a 2TB for roughly $60-70 and then turn around and buy a decent SSD for 100-150 for your OS. So at this point is cost is a factor you just bought 2TB and a say 60GB SSD for $160 and had loads of space and a stupid fast OS and program drive. The raptors have been too much for what you get since SSDs. You had lower then SSD performance and less space then a massive spindle drive. I did use two 36GB raptors when they first came out in RAID 0, and it was fast at the time.... But for the same money I can do a lot more now. They need to lower the price of the drives to compete.
Lastly burst rarely happens, where the SSD excels is latency and small file transfers. if you compare that the raptor is far less of a competitor to the SSD. There are articles pointing this out or more knowledgeable people on this forum then myself that can go into detail.
OCZ has not worked around these limits. All their SSDs with PCIe interfaces are still SATA-based controllers driving them. Just in RAID.
And BlueByte is correct. Burst speed is pretty much meaningless. At writing small random files at a low queue depth an SSD is still 10-20x as fast as any mechanical hard drive, including Vraptors.
Thank you BlueByte ^
The question is, what are your needs? If you're backing up or reading a movie from a 'lowly' 5,400 RPM backup/green drive, you're going to have -plenty- of speed for the program to keep up with, and then some. You don't need a velociraptor in order to do this, and you can save that cash that you would spend on one and put it towards a larger drive, or multiple smaller ones for RAIDing purposes.
And for those that interface with a mechanical drive more often, the speed that you gain using a faster drive is usually unwarranted for the price cost, compared to a SSD + "green" HDD solution that would be more effective in the first place.
Also your math is off. 3 Gb/s = 384 MB/s, double that for 6 Gb/s.
If you look past your e-penis, you'll find that raptors don't really need to exist anymore, the market for them is all but done.
I agree w/ everything you are saying though.
He didn't include overhead either :P
But you're right of course. Point still stands though!
We can do some more maths though! The 600 GB velociraptor has 64 MB cache. At 270 MB/s, you could empty/fill that cache in less then a quarter of a second! Without the drive's overhead, of course.
And lastly, to close this argument: Everyone knows SSD's are better as boot drive, so that relegates Raptors to storage drives. The extra price is not worth the 30 seconds you save to copy a movie to your storage drive, even more so when you probably save it there in the first place. Hence why most people have 5400 RPM storage drives and dont think twice about it.
I'm really not sure of the point of this post to be honest. SSD's are exponentially faster as boot drives, and nothing else needs any more speed then 5400 RPM, or its stored on the SSD? :whistle:
15K SAS drives like the Savvio and Cheetah were always an option if you wanted a really fast spinny drive. Velocoraptors seemed like a low-budget consumer version of a server drive. If you really want a server drive, then buy a server drive and get it over with.
With SSD's where they are today, the applications where a 15K drive (or array of them) is the best choice are becoming very narrow and rare. Nothing in my various workflows needs a drive like that now. I lean more on the network and my Linux-based fileserver (stuffed full of 5400 rpm drives and DRAM). Everything that needs speed is on an SSD, and nothing remaining is really constrained much by 1G ethernet. All a workstation really needs is a small SSD for the OS and a local My Documents folder, while everything of bulk is on the server. I'm more looking forward to when 10G ethernet comes down in price.
You also have to remember that current high capacity 7200rpm drives are actually faster than a velociraptor in many cases as well...HWC review of seagate barracuda 3tb in RAID 0 (I know its in raid, but the review also contains info for a single drive and that's the info I am going from).
With a quick look I believe it is faster in every benchmark than the 150GB velociraptor. If you have a velociraptor then use it (its still a good drive), but if you don't then I wouldn't bother with one.
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