Introduction to hard drive technology

Great article, it cleared up some questions I had about NQC.

Good work!

 

I just built a couple of HD video recorders, to deal with uncompressed 1080p25 video recording. The required rates are around the 200Mbyte/sec mark, which sounds scary.

Then you put six Seagate 750Gb 7200.10 disks on a single SATA RAID controller, stripe them all together in RAID-0, and you suddenly have a two and a half terabyte disk that goes at 430 megs a second.

Modern hard drive technology is, and I believe this is the correct expression, "for the win."

Phil

 

I'm looking forward to your RAID article as well, as this opening salvo on storage technology is somewhat of a tease--there, I said it...it offers up lots of possible directions for future reading, and brings some of the people not-in-the-know closer to understanding what's in hand.

Suffice to say, I agree there are so many factors which define a drive's performance, but equally important is what that drive is connected to. One could have the most powerful engine in the world, but it does little good if it's plugged into a Mini with the skinniest tires and the most horrible suspension.

There was an article by another site, which gave me a direction to pursue higher storage performance, but it seems dated, as there isn't a reference to the SAS drives nor any controllers that allow SAS and SATA to be in the same box.

Your site and articles are of a higher caliber and quality than so many other stops on the 'net. Keep up the good work, and again, I look forward to your future articles.

 

Without being pushy, any date to look out for?

 

I don't know yet, probably next month - I haven't spoken to Josh about the specifics yet.

 

Cheers.

Just I'm building three new high-end systems soon and don't know whether to Raid 0 some Raptors...

 

Awsome pictures in this round up

I like the idea of raid but due to limited funds have never indulged. I do however have some anciant scsi hardware (ISA controller card and 1gb HD) which is fun to get out

 

Its particularly tough to actually do a quantitative benchmark for dekstop performance - as you will have read in the article. The only way to do this effectively is to devise a completely custom benchmarking suite, which ain't easy.

in Windows, you can turn NCQ off in the device properties of your disk controller.

RAID setups are predominantly designed for server use, wheras a hybrid drive is designed primarily for mobile and desktop use. For servers, its tends to be a case of more disks = more performance.

If you cant wait for the RAID article, the short answer is don't bother


BlueMax: The aim of the article was to clear up some myths surrounding hard drive performance, as opposed to explaining the basic underlying technology. I think the opening page does a pretty good job of explaining its intentions.
Some parts of the article do get a little heavy, but I've tried to be as straightforward as possible in the explanations behind it.

 

Good article, I like it tbh, it gives plenty of info without being too sciency, which some people don't want. Clears up some of the crap that's always floating around in the forums too.

Nice to hear a RAID article on the way too, can I suggest it be placed in a sticky in the Hardware forum?

 

is it worthwhile using I-Ram for your primary HDD though

i mean that's still going to blow Flash memory out of the water for a long time, and the biggest limiting factor is the interface, so a 600MB/s interface would definitely be useful for I-Ram

ofc its only really worth it when we can get about 16gb of storage or something, that's plenty enough for windows and your programs, just not games, photo shop and media (and other big stuff)

Very nice article though, and its nice to know all this stuff, although i too wonder, can you turn of NCQ ?

Note:
If you go to
Control Panel -> System -> Hardware -> Device Manager ->
Right click your interface (IDE ATA/ATAPI controllers)
Primary / Secondary Channel
Uncheck "Enable Command Queuing"
However, I'm not sure if this is right to get rid of NCQ, could BT confirm ?

 

I've bought a 250gb Seagate 7200.10 IDE drive just last week and transfer rates top out at 75mb/s, while my 74GB SATA Raptor peaks at 68mb/s on a 865G motherboard.

It is a misconception to think you're getting a faster drive just because it's SATA.

The article was a good read, I particularly liked the server/desktop explanations of usage.

 

Yup, that's how to disable Native Command Queueing.

 

Dated review Something similar may be considered possible, and coming from BT, would be updated and more comprehensive--not to mention, more relevant.

Nice sig. Our RAID controller manufacturer points to that older review to indicate the performance differences between 128M, 512M and 1024M for the onboard cache. From Areca FAQ

Wouldn't a hybrid drive still be faster than a strictly mechanical PATA/SATA drive?

And as for the iRAMs, the real limiting factor was the number of PCI slots to plug it into for power. Gigabyte had made prototypes of a hard drive slot form factor, but that still hasn't seen the light of day.

Consider this

And lastly, after speaking with a WD engineer who worked on the Raptors, he said that the first 20G of a hard drive were the fastest, so if you could split the drive up with that part in an array, and skip the rest (or maybe just use it for low usage storage), then quite possibly it'd be another speed benefit.

Food for thought...

My $.02

 

using only the first handful of tracks of a drive is called short stroking, the same principle applies to any hard drive. The outside tracks on a drive give the highest sustained transfer rates, and limiting the actuator to only these parts of the drive speeds up random accesses.

No idea how a RAID controller would handle hybrid drives. Technically speaking, an array of hybrid drives would outrun an array of strictly mechanical drives, provided that the controller knew what to do with the flash memory (I'm not aware of any current controllers that do, perhaps it could be implemented with a firmware update)

 

I always consider Hard drives as a performance factor apart from the graphic card and cpu. A fast hard disk can boost the overall system performance

 

I saw nothing wrong with the article and for the most part it just confirmed what I've suspected and read in bits and pieces from various places: RAID, NCQ, and most of the other server stuff isn't really a help for single user machines.

I've been waiting years for something like flash drives to become affordable (ever since I learned how to make a RAM drive in DOS - those were real useful for a speed boost).

 

You didn't mention anything about memory paging. I find that 90% of the time that I'm waiting for my PC to do something it is simply retreiving data what should be in the RAM from the disk.

Some questions I'd like answered are how does Windows decide what to page? How does the HD cache take the pagefile into consideration? Why doesn't the OS use 90% of your RAM before loading data onto your disk?

My work PC is tremendously faster than my home PC when it comes to simple things like going from one tab to the next in Firefox. I think this is down to the 3GB of memory in the former and the 1GB in the latter. I think you'll find that your hard drive is mainly used for "memory" rather than media files and this is why flash based hard drives and other new technologies such as MRAM will be so important to PC users.

 

I would think that's a question for the Windows and OS Software section. If not there, you can check here and then do a search on other DriverGuru posts. DriverGuru gives some very in-depth explanations about OS paging and the inner workings with Windows (and sometimes the differences between versions, from 98, 2K, XP and beyond).

If either of your computers seems to be slow, then adding more RAM is probably the way to go. A faster hard drive or storage subsystem won't give as much performance benefit, FWIW.

I suppose the SSD drives and the hybrid drives may give faster performance, although I'm looking for faster load times in games. It's great to have a box that loads fast enough that the Windows boot screen progress bar will show 3 squares, at most, but that isn't quite the benefit I'm reaching for.

YMMV

 

know i need to find out if NCQ is enabled/disabled and then proceed to disable if neccasery, but that will have to wait till later - any suggestions welcomed

edit - should add this is for ubuntu linux

edit 2 - hmm is tagged queuing the same as NCQ? i went to to system > device manager > ide ata/atapi controllers and in the primary and secondary IDE channel and couldnt find under any tabs anything to do with ncq but under system > device manager > disk drives > hitachi longish code SCSI Disk Device - and under the tab SCSI Properties i found disable tagged queuing (unchecked) note this is all under xp

 

that and the fact that buying DDR memory to use as a HDD is pretty dang expensive
Plus it maxed out the SATA interface it was plugged into - easily

Its a bit of a pain that PSU's don't have standby power connectors for stuff like iram