I saw a tweet today about what it claims is "the tallest PC case" which appears to have been made by SuperMicro:

Picture from Twitter

Further tweets in the thread include pictures of the inside of the case, which has a ton of empty space. It looks like there is enough room to fit all of the components in half the space (or to make the case just a little bit deeper if you want to be sure disk/disc drives won't overlap the motherboard):

inside of case

Other people replied with pictures of their own super-tall cases.

Was there an actual technical reason for manufacturers to make such tall cases?

  • Comments are not for extended discussion; this conversation has been moved to chat.
    – Chenmunka
    Commented Oct 15, 2021 at 9:26
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    I had one like that which was completely full. Multiple full length expansion cards. All drive bays filled with floppies, CDs, and hard drives. Commented Oct 15, 2021 at 21:50
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    Get two, and lay an old door on top. Instant desk!
    – Criggie
    Commented Oct 16, 2021 at 1:29
  • Biggest advantage is there in the replies "adult human with larger-than-average hands stands a chance of building PC without slicing hands open on razor sharp 0.6mm steel" :D
    – Caius Jard
    Commented Oct 16, 2021 at 11:09
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    @CaiusJard Except that to save your hands you want a large desktop (horizontal) case since those don't have all the sharp-edged, fixed structural stuff in place after you take the lid off...
    – Lou Knee
    Commented Oct 17, 2021 at 15:23

13 Answers 13


Disks take up space. At sub-gigabyte capacity you may want more than a couple. Add the CD-ROM drive, the 3.5" floppy, the 5.25" floppy, and you're into skyscraper territory.

You can't put the discs lower in the tower (over the motherboard) because they'd be in the way of the incoming airflow to the motherboard. Those beige things on the lower right are fans.

  • I have several cases from the last 20 years with fans in front of the 3.5" bays. I guess maybe they were worried that if the fans were behind other components they would be too hard to replace if they failed?
    – Moshe Katz
    Commented Oct 13, 2021 at 13:58
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    In the 1990s there were still a few full-height hard drives floating around (occupying two adjacent 5.25" bays), so that's another aspect of storage to consider.
    – john_e
    Commented Oct 13, 2021 at 16:23
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    This. The pictures show six 5.25 drive bays. Clearly this tower was for someone who needed a lot of storage.
    – DrSheldon
    Commented Oct 13, 2021 at 16:53
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    The beige things on the lower right are holders for the far end of the full-size card. I think putting a fan inside that, as seen in the upper-left where a card stabilizer doesn't make sense, is a retrofit to the ATX design.
    – JDługosz
    Commented Oct 14, 2021 at 15:10
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    @another-dave The pattern is holes, and a generous number for cases at that time - some had none at all. I'm pretty sure that case also has a slot at the base of the fascia that doubles as a grab-handle for pulling the front off. I did work with a bunch of machines in a variety of tower cases back then, but the specifics have munged together in my memory over the years. The other confounding factor is that there wasn't a consensus as to whether the PSU sucked air into the case or blew it out... (1/2)
    – Lou Knee
    Commented Oct 17, 2021 at 14:49

I have that case sitting behind me. Actually, the air holes on the side look slightly different, and it lacks the SuperMicro branding, but everything else about it is the same. According to my PC construction page, it's an "Extra Series model 7890A (ATX full tower) w/300W power supply", and I put a 266MHz Pentium-II inside it.

Part of the reason I bought it was to have room for all the various drives. 5.25" floppy drives were still a thing, 5.25" hard drives were disappearing but mounting 3.5" drives in 5.25" brackets was common, CD-ROM drives were essential, CD recorders were becoming affordable, etc.

Part of the reason was ventilation. The computer I built before this one used very early 2GB Seagate Barracuda drives. While assembling the computer I had everything running for a while with bits and pieces sort of spread out. I shut it down and went to install the first drive, and had to drop it to avoid burning my fingers. Those early 7200rpm drives ran hot!

To prevent the drive from dying an early death, I added small fans that blew air across them to the case. To make the airflow work I used the lowest bay for the drive, the next bay up was open to the air and had a fan, the one above it had the second drive, the one above that had another fan... so that's 4 bays just for the hard drives and fans.

I bought this case with the same expectations. Looking into the case right now, there's a small fan on top of the hard drive, but IIRC drives were running cooler by then and it probably wasn't needed.

The final reason for using a large case was comfort: I got tired of getting my hands chewed up by metal edges in a cramped space. Modern "tool free" cases tend to have rounded edges and pull-out drive mounts, but the early ones were vicious. The larger space was just easier to work in when installing drives and the various cards. (Don't forget that you might need a video card, sound card, SCSI adapter, Ethernet card, and in my case an AV/Master video recorder.)

  • 15
    A friend of mine was practicing sword fighting, his troupe made shows on medieval markets. Never got a serious injury. But while working with a cramped case with sharp edges, he managed to cut a tendon of his thumb while trying to pull out something. Yeah, they were vicious.
    – DarkDust
    Commented Oct 14, 2021 at 7:52
  • JOOI, are there actually vent holes in the lower front of the case, or are the fans in that area starved of fresh air? It looks more like dimples than holes, from this angle - and is there even a hole in the metal that those lower front fans are mounted to? Commented Oct 14, 2021 at 11:26
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    @AndrewMorton: I pulled the plastic front off to check (grab at the bottom and pull). Those are actual holes, and even have little air filters behind them. There are holes in the metal case for the fans and also for the adjacent speaker. The airflow isn't fantastic, but it can actually draw air from the outside.
    – fadden
    Commented Oct 14, 2021 at 14:45
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    In addition, a lot of people during the late 90s/early 00s might have had 2 or 3 optical drives: one CD-RW/ROM and a separate DVD ROM were common before drives capable of writing DVDs were available or common.
    – nexus_2006
    Commented Oct 14, 2021 at 16:38
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    @nexus_2006 which lasted awhile too. Early on it was a cd-rom, then you added a cd-rw but kept the rom since it read faster, then you got rid of the cd-rom and added a dvd-rom and kept the cd-rw, then get rid of them for a dvd-rw, possibly keeping all three to have the fastest reads alongside the fastest writes.
    – Quantic
    Commented Oct 14, 2021 at 17:54

In addition to just general ease of service & upgrades, motherboards used to be much bigger, particularly if you had a motherboard with lots of RAM and built-in ports. To the right of the motherboard, you can see several square holes that could hold additional standoffs for a larger motherboard. While ATX motherboards, as far as I know, were never that large, AT and other types were. This case may have been an updated-for-ATX version of an older AT case.

In addition, the expansion cards used to be much longer, so even if disk drives could fit in front of the motherboard, sometimes that would limit the length of some of the cards, which was OK for the average user because they didn't add much to their systems. But for the power users with 3 hard drives, both 3.5" and 5.25" floppy drives, etc., that was more of an issue.

  • 2
    AT motherboards stopped being AT size with the IBM 5170 Type 2 (which was "Baby AT"). That was circa 1985. Considering that these tall cases didn't come out until many years later, "large motherboards" is not a very good argument for their existence. Commented Oct 13, 2021 at 23:20
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    There are contemporary server boards (E-ATX and custom form factors) that are huge. And Supermicro is actually one of the brands making some, and also big cases for these. Also, there are the PICMG industrial form factors that could make for some quite large machines... Commented Oct 14, 2021 at 7:36
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    @CodyGray: But the length of expansion cards are a good reason. I still have a few full-length or almost-full-length cards in my archive. So if you already need to reserve space for the expansion cards, you can as well make holes for large mainboards.
    – DarkDust
    Commented Oct 14, 2021 at 7:48
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    @CodyGray: There certainly were full-AT motherboards in the early 1990s - the TMC MET48PX was a 486 server motherboard with eight EISA slots and up to 256Mb of RAM.
    – john_e
    Commented Oct 14, 2021 at 8:40
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    I had a Soundblaster AWE 32. That thing was huge. But, annoyingly, not quite large enough to fit in the expansion card holder... Commented Oct 15, 2021 at 13:14

A "full-length" ISA card could be over 13" from the mounting bracket to the end of the card:

Hercules MDA card by Konstantin Lanzet on Wikipedia

This case gives you enough room to have a full complement of full-length cards on the motherboard, plus up to three full-height drives (the same width and depth as today's standard optical drives, but twice as tall)

full-height 5.25-inch ESDI drive

up above. If it was shorter, the drive bays would interfere with at least some of the card slots, so you would have to limit yourself to half-length cards in some of the slots, or remove part of the drive cage, limiting the number of drives you could mount.

Also, older PCs tended to contain many fat ribbon cables:

an IDE cable and a floppy cable

besides drive cables (pictured above), you might have some cables for serial or parallel ports, special audio or video expansion, and even the ATX power cable used to be as wide as the connector along its whole length, before manufacturers started bundling the wires into a round cable. All of those ribbon cables and all of those add-on cards were really good at blocking airflow, so having some extra space in the case for air to go around was a fine idea.

You have a photo of this case with a small motherboard, one half-length card, one half-height optical drive, and one half-height 3.5" hard drive. Of course it's pretty empty!

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    These cards are the reason for cases like this. They dictated case design standards for years. The fan cover on the front of the case has slots on the back that full-length cards would fit into, that shows you how far these cards extend. Computers used for industrial control purposes (for example) frequently had multiple full-length cards, so the space in front of the motherboard was unusable for anything else.
    – bta
    Commented Oct 15, 2021 at 16:24
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    +1, the slots @bta mentions are a dead giveaway that the case is meant to handle full-length cards. Of course, the computer in the photo has a motherboard with no ISA slots and what seems to be AGP, which might confuse some. But the case wasn't designed with that motherboard in mind.
    – TooTea
    Commented Oct 16, 2021 at 19:28
  • @bta Umm, so exactly how does the need to hold full length cards require a tower case that's tall, rather than one that's front-back deep?
    – Lou Knee
    Commented Oct 17, 2021 at 15:16
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    @LouKnee Other factors constrained the depth. The IBM PC and XT had created unofficial standard sizes for cases due to their popularity. Making the case deep enough to hold a full-length ISA card plus a full-length drive bay would mean the case would likely be too large for most office furniture. Cooling is also easier since the intake-to-exhaust distance is shorter compared to growing "out", so fans can be quieter (important in office environments).
    – bta
    Commented Oct 19, 2021 at 0:20
  • But the IBM PC and XT were desktop cases - they were limited in depth by the need to leave enough space for the keyboard in front of them; floor-standing towers aren't. They could trivially have been at least a foot deeper.
    – Lou Knee
    Commented Oct 24, 2021 at 12:25

I built a 486DX2/66 in one of those massive towers back in the day. The motherboards back then were full size, and some cards were 'full length' cards (like Vesa Local Bus, etc). Many times the I/O relied on an actual Multi-I/O card in addition to the motherboard (things weren't as integrated)... So it doesn't take long before Video, Multi-I/O, Audio and any other exotic cards stack up... You also wanted plenty of room for a 3.5" and 5.25" floppies, CD-ROM, maybe a Colorado Tape Backup and a few bays for mounting HDD's internally. Having a large roomy case was an advantage to how much you could fit in the box, and how easy it was to tweak/modify.

  • Indeed. At one point in mid-1990s my PC had a VLB graphics card, a Gravis Ultra Sound card, a Roland SCC-1 midi card, and a specialized card to access a CD-ROM drive in ISA slots plus a 3dfx Voodoo graphics accelerator in a PCI slot. And somewhere, there was also a network card (BNC) There wasn't really much room left in the tower case.
    – Schmuddi
    Commented Oct 14, 2021 at 10:01
  • I'm surprised at how long it took to see a reference to a tape drive. If you had a 5.25" floppy, 3.5" floppy, CD, and tape drive you had that case halfway full and that's before you started adding hard drives... Commented Oct 16, 2021 at 0:22
  • Come to that, you could get a Nikon Coolscan slide and film scanner (surely an essential peripheral for every computer system?) in a 5.25" form factor.
    – dave
    Commented Oct 17, 2021 at 16:15

Can never have too many bays, you need them for your:

  • Simple storage drawer
    enter image description here

  • Stowable third monitor
    enter image description here

  • Ciggy lighter and cup holder
    enter image description here

  • Easy-bake oven
    enter image description here

  • Toaster
    enter image description here

  • while not strictly drive bay, the extra space has been used for a coffee machine:
    enter image description here

Although I suspect many of these came after someone looked at their empty drive bays and tried to make something "useful" out of the space that was already allocated.

  • 2
    I actually have one of those storage drawers in one of my old PCs. I used it for keeping things like driver disks right there with the machine. My current machine has a drive-bay LCD instead, since the mounting holes on the drawer aren't compatible with Antec's rails.
    – ssokolow
    Commented Oct 15, 2021 at 1:28
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    The EZ-bake was an April Fool's item. The others, though - including the toaster - were real. :D
    – BrianFreud
    Commented Oct 15, 2021 at 12:36
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    I have a tray in a drive bay in my livingroom Home Theater PC. The tower is hot huge, but it's more than what is needed by the current build; one of the 3.5" bays is repurposed to hold a multi-card reader, the other still has the floppy disk but it's not plugged in. It uses one external half-height bay for the Blu-Ray, and the HDD and SSD are in the lower area, so there are two external drive bays available. I have a drawer in one that holds USB things, dongles, etc.
    – JDługosz
    Commented Oct 15, 2021 at 14:08
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    The Toaster or oven was a common joke when CPUs started taking a lot of power. When I got a Pentium Pro, people joked I could use a spare drive bay as a pizza warmer. Now that much TDP is considered "mobile" !
    – JDługosz
    Commented Oct 15, 2021 at 14:10
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    Well, if you're going for stuff to fill drive bays, how about a drive bay CRT (LGR Oddware and it even includes a picture of a case with the same front but different side-panel vents at 4:10)... a nice reminder of the days when Windows only offered an RDP server for the most expensive editions of the Windows NT line, it was a pain to lug a CRT into place, and server racks weren't something less-than-enterprise operations just thought to go buy on Amazon.
    – ssokolow
    Commented Oct 15, 2021 at 15:41

To add to other answers, you have to consider how changing connections have shifted the mind-set over the last three decades.

Connections to external devices have improved tremendously; we now have really good, standard, well-supported connections (physical connections such as USB3/USB C and Thunderbolt; and wireless ones such as wifi and Bluetooth), so almost anything you want can be connected to your computer without putting it inside the box.

But that situation has only arrived gradually. Connections to external devices used to be generally proprietary, slow, hard to configure or use, unreliable, specific to particular device types, and/or needed the device to be bigger, heavier and/or more expensive than a device which fitted inside the box. So in the Olden Days™ internal devices were the default: once fitted, they were simpler, cheaper, smaller, and more reliable. Or, in many cases, they were the only option!

So if you were a power user who wanted (say) a few hard drives, a DVD reader, a CD writer, one or more floppy drives, a sound card, a modem card, connections to a dot-matrix printer and a laser printer, not to mention a decent graphics card, then you needed a machine with enough internal connections and physical space to hold all that! In the mind-set of the time, a physically bigger machine was a better machine, because it allowed you to do more with it.

And the proportion of power users was a lot higher back then, because most ‘ordinary people’ didn't use computers. Why would they? If they didn't want to play games, or print out correspondence, or do their accounts, there wasn't a lot of reason for the expense of a computer. That changed very gradually, once the Internet became popular and more people started using email and the WWW — and then manufacturers started making smaller, simpler machines for such people. Arguably, it was the release of the iMac with its consumer styling, small size, limited connections, and use of general-purpose USB instead of separate proprietary connections, that really drove the move towards smaller machines and external devices.

Since then, PCs have got progressively smaller because they no longer need to be so big — modern connections allow almost everything that you could put inside the box (except processing and RAM) to be done from outside, usually with similar speed and reliability. So size now has to be justified; it's no longer the default that it was.

  • Also, don't forget internal tape drives, which sometimes were full height.... Commented Oct 26, 2021 at 16:58

The key to understanding the use-case for such a tall tower is thinking of what it allows at full occupancy that a shorter case wouldn't.

Most importantly, those horizontal ribs on the housings for the two fans at the bottom on the two fan housings at the bottom are supports for the ends of full-length expansion cards to slide into.

I don't know if I've ever seen one in a consumer setting, but, according to my copy of The Winn L. Rosch Hardware Bible, Fifth Edition, PCI does spec a "full-size" form factor 312mm (12.283") long and, if that case is designed to take ISA cards, then you're accepting cards up to 340.7mm (13.415") in length.

Looking at the motherboard sitting in the case may make that card length hard to believe, but I did a quick "drop into inkscape and scale some lines" comparison to extrapolate the depth of the case from the length of those PCI slots and it checks out.

...and, as others have pointed out, those square holes visible on the back plate are for clip-in standoffs/screw sockets for larger motherboards.

That motherboard looks like it might be a microATX or flexATX board, going by Wikipedia's numbers, since it looks to be around 8 inches deep, and AT (12" x 11-13") boards would be a third again as deep... and that's assuming the case doesn't support standoffs in a configuration for form factors like SSI EEB (12" x 13").

(In fact, Winn L. Rosch gives dimensions for "Mini-ATX" that don't match anything on Wikipedia but fit my estimations of that motherboard's size even better: 11.2" x 8.2" (284mm x 208mm))

Whatever size it is, it's only two thirds as deep as a full-size PCI or ISA card.

If you wanted to support both full-length cards and lots of drives in a shorter case, you'd have to make it much deeper and the preference at the time was to build cases taller, not deeper.

  • 3
    Yeah, I guess the answer is simply that the case and the components in the picture come from two different eras. The components are much smaller and much more integrated than the ones the case was designed for. I, too, remember the times when the motherboard only contained the CPU and the RAM and maybe the floppy controller, and everything else was on separate cards: an I/O card with serial and parallel ports, a video card, a sound card, an Ethernet card, maybe an ISDN card, at least one IDE or SCSI card, maybe both, maybe a RAID card – and that's before you start adding application-specific Commented Oct 13, 2021 at 22:58
  • … cards such as video capture or accelerators of various kind. Add in at least one HDD, CD, one or two floppies, maybe a tape drive or an Iomega Zip or Bernoulli, and that thing starts to look real small real fast! Commented Oct 13, 2021 at 23:03
  • @JörgWMittag Not to mention that, being a case of a size marketed to server builders, you might still need an AT-sized motherboard to fit all the RAM slots and/or CPU sockets you want. (eg. I once had a retired Compaq server running Windows NT 4 that needed a big motherboard because it was a dual-socket Pentium 90.)
    – ssokolow
    Commented Oct 14, 2021 at 15:28

Technical advantage? Not really. Practical advantage? Perhaps.

On the technical side, it isn't really an advantage it is creating more empty space which is being warmed by the components and probably multiple "dead air space" which is not helping cooling. Of course, you could install multiple fans in such a box but you're still not optimizing airflow. So in general unless you've got a special case (of which the pictured isn't really) or you've created air passages for ventilation, the larger case isn't any more technically advantageous to a desktop.

On the practical side, there is one key thing: storage. As another-dave said, "disks take up space". If you are a storage-hungry home power user or a small organization that doesn't want to invest in disk arrays, network storage, etc., then you may have been better off setting up an x86 box with an Adaptec RAID controller and multiple disks and having them all mounted inside a giant case like the one pictured.

To try to peg a date of the pictured tower (lets assume 1998), people weren't setting up Synology NAS servers for small businesses but having one server box to support their network and throwing lots of disks in there. Corporate data centers were a bit more similar to what you see today, i.e. rackmount 1U/2U with just enough local disk to get up and running and then either a network or fiber to a disk array (e.g. EMC). But while the corporate model was more desirable, it was far more expensive than the SOHO single-tower model.

So in short, large towers were good for one thing: storage. As far as any technical advantages? No since the add-ons that would really change the game for you could most likely be installed in a much smaller case.

  • Large towers are poor for storage, because if you stuff the top with (heavy) drives the whole thing becomes unstable and a nightmare to handle when you need to pull it out to work on it.
    – Lou Knee
    Commented Oct 17, 2021 at 15:41

It's simple: if it wasn't that tall, it would be too short.

This is an example of what we used to call a "full tower", which would stand on the floor maybe next to (or under) a desk. So, the height comes from the need to easily reach the important bits whilst sat in an office chair: note how the main power switch is at the very top, well away from the reset switch and LED's. The 3.5" floppy (or Zip) has a dedicated bay at the very top, separate from the 3.5" bays for HDDs. The CD-ROM would go in the top-most 5.25" bay; that way common Walkman-style earphone leads can just about reach the 3.5mm jack and the user can reach the play & eject buttons.

So the height (and depth) comes from the need to co-exist with office furniture.

(I have one of those very cases sitting here right now. Been involved with it since 2001 - 20 years ago - and it wasn't new then!) Notice that there is no facility whatsoever for USB connections on the case itself - to plug in a thumb drive you have to pull that huge thing out and grub around at the bottom at the back looking for the USB port on the motherboard. (Or fit a later adaptor into a drive bay!)

This specific case is particularly spacious as it was intended for workgroup server applications (i.e. lots of drives, likely SCSI RAID). I've seen smaller (narrower) cases with as many if not more drive bays (cabling nightmare, especially with ribbon cables as hobbs mentions) but still the same height, and also much smaller cases that would still take one full-length ISA card.

Edit1: for reference, the power button is 635 mm above the floor.

Edit2a: A significant limitation of these tall cases is that if you fill the bays with drives then the whole machine becomes top-heavy and unstable when you need to pull it out to work on it, or even just to plug something in. They could have been done the other way up, with the motherboard at the top... but then the floppy drive would be out of reach.

Edit2b: A lot of the other answers here talk about the need to cram in full-length cards and lots of drives, but that fails to answer the question: e.g. you can move the drive bays in front of the cards by making the whole thing deeper - exactly what rack-mount servers did, and some of those were very long/deep (e.g. early 2000s Supermicro storage server: 3U, 16 bays and takes full-length PCI-X & PCI-E cards. From an old photo I estimate that chassis is well over 800mm long/deep). The tall full-tower form-factor hung around for the best part of a decade simply because it matched the height and depth of typical office furniture. A midi-height full-depth tower would have been a trip hazard if sat on an office floor! (I dimly recall seeing a wide tower - two side-by-side columns of bays. Daft idea - with that use of floor space just get a 12U cabinet, or even a full-height rack ...)

  • Double-wides don't sound that bad. I used to have a late-1980s personal computer that had an almost double wide case, a VAXstation in a BA123 box, which had room for 3 full-height disks or tapes - I don't think half-height was a thing then. It fit nicely under my generic cublcle desk, and rolled out on casters.
    – dave
    Commented Oct 17, 2021 at 18:27
  • Double-wides give the stability, but to reach the top comfortably they still have to be the same height, so for an interactive machine you end up with a lot of empty space. And if you are after mass storage, then a 19" cabinet under the desk can hold 3 COTS rack-mount servers each with as much disk if not more than you can stuff in one tower...
    – Lou Knee
    Commented Oct 23, 2021 at 22:38

Yes, I'm someone who looked for tall cases! I simply needed more room for drives and other peripherals. I dreamed about having a double wide case to provide more drive space!

Motherboards also had more slots back in the day. And, I've also owned mainboards that had a large number of slots, to support more stuff. Back then, fewer things were built into the motherboard, and it needed lots of cards.

As boards got shorter, I found the drives not overlapping the mainboard was handy for working on it, as well as providing airflow around the RAM. But I already had the large case from a previous build.

Besides drives being larger, there were also internal mounts for things like tape backup, different kinds of removable media drives, and if there were still empty bays they could be used to mount front-facing connectors and indicators.


I believe the answers so far are over-thinking this.

The original IBM PC was horizontal, not vertical. There was no such thing as a "Tower". Many, including myself, realized that this took up valuable desk space and set the case on its side. After enough people started doing this, someone (at least by the early '90's) came out with plastic feet to set the case in so that a case originally designed to be horizontal but set on its side would be more stable. (I had these also.) Manufacturers realized that to expand the contents of the case without occupying any more desk or floor under the desk area, you could just make the case taller. "The rest is history" - The majority of PC cases have been vertical ever since, and the more things they were expected to contain the taller they became. End of story.


That looks like my old SuperMicro SuperTower SC750. That case was top of the line for its time, around 2000. It fit even the biggest ATX boards, with plenty of space for drives, expansion cards, fans, and a big enough power supply to run it all. It also had detachable sides on both sides, which was unusual at the time. There also was plenty of space to allow airflow in those early days of home PC cooling.

My memory is that it also was the case picked for the ArsTechnica "God Box" at the time.




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