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Loading ...Give us 5 1/4″ HDD’s
l3v1ck
For years now there have been two standard drive sizes in desktop PC’s, 3 1/2″ and 5 1/4″. For as long as I can remember hard drives have always been sold in the 3 1/2″ variety.
The question is why?
In terms of performance the outer areas of a platter on any hard drive give the best performance, because more data is going past the drive head per revolution. So logically if a drive platter was larger, you’d get better peformance.
Then there’s capacity. Quite simply, the larger the platter the more data you can fit on. Not only that, 5 1/4″ drive bays are also deeper than 3 1/2″ bays, so hard drives made for them could fit more platters in a single drive.
Last but not least we have the issue of space. Most tower cases have the 3 1/2″ drive cages just about level with where the graphics card fits into the case. In the modern era of ever larger graphics cards, fitting them into an existing case is becoming more problematic as the hard drives get in the way. If however, you got rid of the 3 1/2″ drive cage and fitted the hard drives in spare 5 1/4″ bays, there would be plenty of room for larger graphics cards. Granted, some people would say that older cases might not have enough airflow for these high powered cards anyway, but I disagree. Providing you cave good case fans and maybe a graphics card that vent directly out of the case, I can’t see there being too much of an issue.
So why don’t hard drives offered in 5 1/4″ sizes? I’m assuming there must be a technical reason for it as it seems to be such an obvious thing to do. Any ideas?
maybe the inertia of a larger platter with higher mass would reduce seek times and increase power consumption
My assumption would be something to do with the increased size leading to lower stability in the platter, increasing the risk of the drive head colliding with the platter. You could increase the thickness of the platter, but this would probably have an effect on the speed at which the platter could spin, increasing access times. Complete guesswork though.
I managed to place my main comment about this in the SSD’s entry:
[url=http://www.custompc.co.uk/blogs/andrewlevick/2008/02/11/ssds-taking-pagefile-in-the-right-direction/]here[/url]
(and let’s hope the url tag works in the comment screen)
On the graphics card issues, you can already remount existing hard disks with a mounting kit, they’ve been around since the year dot. However, there have been 5.25-*shaped* drives since the 8-Bit days, even if they only took old-style floppy disks so they seem a bit olde-worlde now, even if you’re talking about an internal device. When 5.25 HDDs were relaunched in the 90s, Quantum refused to try to compete on performance so Maxtor never bothered trying them again post-takeover. As the switch to the 3.5in form factor became permanent, it wouldn’t surprise me if it was just economies of scale coming into play.
That true about remounting current drives, but it would be nice is the cases didn’t need the 3 1/2″ cages in the first place. Though having said that people do use them to mount card readers, so I guess it’s six of one, and half a dozen of the other.
I have a 7Gb 5 1/4″ HDD… they did do them just dunno why not anymore, i cant remeber the last time I acctualy used proper 3 1/2″ bay i tend to just wrench em out and bung a radiator in XD
Western Digital did make a 51/4″ drive back in the 90’s. From what I remember it was a 5400 rpm but obviously had quite a large platter which resulted in very slow seek times.
My memory is a bit fuzzy but when I had my shop we did use a few as a budget option which is exactly what they were intended for they were either 10GB or 20GB I recall - might be wrong, however it was at a time when 40GB was considered huge!
Because of the slow seek times of the large platter, I think largely they would be given a slating in this day and age simply because we demand “budget” and “performance” from everything we buy!
Given this it is easy to guess why Western Digital went the other way with their latest performance drive the Velociraptor and have used a 21/2″ platter size.
As l3v1ck points out, mounting kits to convert 31/2″ upto 51/4″ are readily available for just a few quid.
Regarding why 3-1/2″ drives have taken over the market:
1. Today most computers are made and sold by outfits like Dell, HP, IBM, Gateway, Acer, etc.
They buy parts by the trainload cheaper than you or I can buy an entry-level computer at WallyWorld, or the next place down the street.
The percent of the market built by DIY’s is tiny compared with those guys; most designs/decisions conform to the market they are addressing. True, you can order parts, and put yours together, but that is not what’s driving the bulk of the market. Most people want - or are at least willing to settle for - something they can buy for well under a grand, connect a few cables, and be up an running. If you doubt it, ask the next dozen prospective buyers you meet at any of the “super-stores” if they’ve ever seen a floppy drive, or if they know what DOS stands for, or what the first version of Windows was called, or - how about the subject of this discussion - why have 5-1/4″ hard drives all but disappeared.
2. Cheaper to make (smaller platters, lighter-duty parts required to move mechanisms, less material required for the case and covers).
3. Look at the current crop of cases - most don’t have enough room for a spare anything, much less a larger hard drive.
4. 5-1/4″ drives took at least double, but as I recall more like 5 times the power to operate than 3-1/2″ drives do. Today’s STANDARD power supplies barely have enough oomph to operate the M/B, RAM, 1 HD, 1 or 2 Optical Drives, a video card and sound card. This does not include the 500 to 1200 Watt units, only the typical 200 Watt versions you are likely to get unless you are willing to spring another $30 to $50 for a larger unit.
As an aside, I cringe when magazines sell their souls in describing the newest midget system, to sit on a desk in an ever-shrinking cubicle cruelly called a workspace. After all, market forces and obliging writeups have contributed greatly to the trend of tiny cases, requiring stuff to be connected everywhere (externally, naturally) because the little darlings don’t have room for anything beyond what they were shipped with.
However, not all of this is bad. Remember when a 286-equipped machine with a 40-Megabyte (yes, Mega not Giga) HD, 14″ EGA monitor, keyboard, DOS, and little else cost at least a grand.
The first hard drives held 10 Megabytes, and according to industry sources, an often-repeated phrase was “what will we do with all that capacity?”
My first hard drive was 5-1/4″, held 44 MB, and cost over $400. It had 5 platters, and weighed about 3 pounds, or so it seemed.
I’m not sure about the first floppy diskettes, but I think they held about 100 Kb and were 10 or 12 inches in diameter. Later, capacities reached 2 Mb in the 3-1/2″ diskettes.
They don’t need large platters anymore to get huge hard drive capacities. The density has increased to where a terrabyte fits in a 3-1/2″ form factor, probably on a maximum of 2 platters.
Today, you can buy half a terrabyte for about a C-note. It’s much smaller, lighter, hang onto your suspenders faster, infinitely more reliable, takes far less power, and probably more things I can’t think of compared with older, larger drives.
I will go so far as to predict that by the end of this year, at least one “super-store” will sell brand-name, 7200 RPM, IDE or SATA terrabyte hard drives each for less than $100.00, plus tax.
Shrinking components hasn’t been limited to hard drives. It was common for motherboards to cast a shadow of at least 144 square inches. Today’s ATX motherboards are 12 x 9.6, or 115.2 square inches. Today’s smallest motherboards are probably about 10 to 15 square inches.
I don’t know the dimensions, but CPU’s have been meeting or exceeding Moore’s law for a long time (doubling the number of transistors or computing power every 18 months). I suspect that to meet today’s CPU’s capabilities would have required SQUARE YARDS of silicon in the days of the XT, assuming it was possible.
The trends led to other niceties and built-in features such as onboard sound, maybe onboard video, tons of external USB/Firewire connections, and software that does about everything except repel hoodlums on its own.
Nothing I’ve said applies to notebooks, which have a whole ‘nother set of sizes to deal with.
I’m sure there are other reasons, but I hope this gives you an idea of market forces, and whatever else is involved, in determining the directions things have gone.
Now, if only someone could produce new, efficient, automobiles and sell them with ever-decreasing prices comparable to those experienced in the computer industry in the last 20 years…..
Best wishes,
Darryl
y’all forget logistics is the main reason — as darryl has pointed out, its HP - Dell - Gateway shipping em in by the truckload. if each truck only brought in 10,000 as opposed to 16,000 with the same insurance, trucking, cost then it becomes pretty obvious. next, power consumption. it needs a bigger, stronger motor and still not move as fast — my 5 1/4 cheetah 5Gb SCSI HDD from way back was actually more like a 3 1/2 so that it can have a bigger motor and more surface area to cool it down — and it broke when a 250W FSP power supply couldnt adequately feed it when i unplugged it and thought it was a good idea to have that performance in a PIII.. in HDDs, bigger is not always better. i think the 3 1/2 is a good balance — but the next HDDs could be the 2.5″ in a 3 1/2 form factor as a heatsink.
shocking eh?