The upcoming "Merlin" release of OS/2 will likely have higher requirements, at least if some of its extra features (like voice recognition) will be used. Reports indicate that the beta isn't more resource-hungry than Warp 3.0 when only the Warp 3.0 feature set is installed. One major exception: The Merlin beta chews up a lot of disk space -- about 100MB for a minimal installation, and 300MB or so for everything.
As with most software, these requirements, and particularly the RAM requirement, are optimistic. While there are people who are happy running OS/2 Warp 3.0 in 4MB of RAM, these people are rare, and frequently don't run Windows programs. Multimedia support, Internet access tools, and networking all chew up RAM, and so are iffy propositions, even in a system with 8MB. OS/2 is more RAM-intensive than CPU-intensive. If you're satisfied with the speed of a 486 computer, there's no need to upgrade the CPU for OS/2, though even a Pentium computer might benefit from more memory. OS/2 frequently benefits from extensive "tweaking" of settings in the CONFIG.SYS file, and not all of the tweaks are obvious. (For instance, many OS/2 newbies assume that increasing the size of the disk cache will improve performance, but this often has the opposite effect.) There is an OS/2 CONFIG.SYS configuration utility available that contains a database and access program that will analyze your CONFIG.SYS and help you tune it. I strongly recommend that OS/2 "newbies" use this. OS/2 requires not only a 3.5" floppy drive, but a 3.5" A: floppy (though there are workarounds for this which allow installation on a system with a 5.25" A: drive). 35MB is enough to install a fairly minimal OS/2, but if that's the entire free space on the hard drive, it won't be enough. OS/2 also uses a swap file, which can grow to substantial size; and once the user starts adding OS/2 programs, 100MB of free space becomes a more reasonable minimum for serious OS/2 use. Video, CD-ROM, and SCSI support are complex issues, and will be dealt with individually below.
To the best of my knowledge, OS/2 Warp runs fine on all 386 or better CPUs from all manufacturers. This includes Intel 386 and 486 CPUs; AMD, Cyrix, and IBM 386 and 486 clones (including the Cyrix 486DLC and related CPUs, IBM's "Blue Lightning" 486, and the AMD and Cyrix 5x86 chips, which are more 486 than 586); Intel Pentium and Pentium Pro CPUs; and NexGen and Cyrix Pentium clones (the Nx586 and 6x86). I've yet to hear about the AMD 5K86, but I wouldn't expect problems with it. Note that many of these CPUs are available under other brand names, either from companies which re-badge them or from companies (like Texas Instruments, SGS Thomson, and IBM) which manufacture Cyrix CPUs in return for a percentage of the production.
One important caveat about CPUs, though: The next version of OS/2, code-named "Merlin," will include a much-discussed technology known as Voice Type Dictation (VTD). This will allow the computer to take spoken commands and even dictation into word processors or other applications which accept text input. Details are still foggy at the moment, but it appears that a high-end 486 (like a DX4/100) will be required for minimal voice command functionality and a mid-range Pentium (like a P100) will be needed for full voice recognition. This technology utilizes the floating point unit (FPU) of the CPU very heavily, so the fact that Pentium clones have worse FPU performance than integer performance relative to an Intel Pentium means that a faster Pentium clone may be required to get equivalent VTD performance with Merlin. As Merlin is not yet released, however, all of this is speculative. Monitor the comp.os.os2.beta newsgroup or the OS/2 beta FAQ for more information on this. In addition, IBM has announced that they will not be testing Merlin on 386 CPUs. It's entirely possible that Merlin will run on a 386, but this cannot be guaranteed.
A second caveat concerning CPUs is that the CPU must interact with the motherboard, and some motherboards don't work well under OS/2, or with certain CPUs. This is particularly true of 486-class boards using AMD or Cyrix 5x86 CPUs. Unfortunately, a complete listing of good and bad motherboards or motherboard/CPU combinations is well beyond the scope of this FAQ. If you have a PCI system, Pat Duffy's PCI Summary postings may be of help here. I would like to emphasize that most motherboards and motherboard/CPU combinations do work fine with OS/2, but problems do exist with some equipment.
The OS/2 Warp 3.0 manual lists the following as supported video chipsets:
In general, a video board using any of these chips will work fine "out of the box;" however, there are exceptions. Video board manufacturers frequently tweak their boards in ways which produce better performance, but which also make their boards incompatible with "generic" drivers such as those in OS/2. [I do not currently have a list of "problem" boards -- if somebody has such a list, please e-mail it to me and I can include it here.]
If you don't see the chipset used on your board, post or contact the manufacturer to ascertain the availability of OS/2 drivers for the board. Include as much information on the board as possible if you post; for instance, simply saying you have "a Cardex board" doesn't give enough information. Give the precise model number and, if you know it, the chipset used on the board. Many manufacturers have their own OS/2 drivers, even if their board is supported by OS/2 "out of the box." These drivers are sometimes superior to IBM's drivers, but other times are not. [Again, specific information about this might be helpful. Thanks.]
There are three basic classes of CD-ROM drives for PC-compatibles:
CD-ROM drives supported by OS/2 Warp 3.0 "out of the box" include:
Note that for all CD-ROMs, there are potential "gotchas" during installation which are documented in the OS/2 manual. The plethora of conflicting "standards" and hardware means that extra parameters may be required on the driver line in CONFIG.SYS for some CD-ROMs to be used. Before posting with a CD-ROM problem, please check the CD-ROM troubleshooting section of the OS/2 manual. In a worst-case scenario, you can create a set of installation floppies from a CD-ROM version of OS/2 and install from that. DOS CD-ROM drivers can sometimes be made to work for DOS programs using a special DOS boot procedure. (Ordinarily, OS/2 provides DOS programs with access to the CD-ROM drive using its own drivers.)
OS/2 supports the vast majority of hard drives out of the box. EIDE, IDE, ESDI, MFM, and RLL drives all use the same driver -- IBM1S506.ADD. An increasing number of EIDE controllers have drivers optimized to the particular controller from their manufacturer; however, posts indicate that some of these introduce minor or major reliability problems, so they should be used with caution. SCSI drives use either the IBMINT13.I13 generic driver or a driver specific to the SCSI controller in use. SCSI drivers are included for many SCSI controllers:
Drivers for QLogic, UltraStor, NCR/Symbios 53c8xx-based boards, and probably others, are available from the manufacturer. If you have one of the latter boards and wish to install from a SCSI-based CD-ROM, you will need to acquire the appropriate SCSI driver and add it to the OS/2 Diskette 1, or else OS/2 will be unable to recognize your CD-ROM drive. Instructions should be included with the OS/2 driver. Note that OS/2 2.x SCSI drivers usually work under OS/2 3.0, so if you can only find a 2.x driver, try it.
OS/2 support for parallel-to-SCSI adapters is limited at best. Unfortunately, I don't have more specific information on this, though.
The PC BIOS imposes a limit of 1024 cylinders (0-1023) upon hard disks. This limit, in conjunction with limits upon the number of heads and sectors, limits the size of IDE (and ESDI, etc.) hard drives to 504MB, and the size of SCSI hard drives to 1GB. (Most SCSI and EIDE controllers have an option to get around this.) If you have a hard drive larger than this value, it may have come with a DOS driver to allow access to the entire hard drive. If you've used that package, OS/2 may not be able to read the drive's partition table, and thus OS/2 will not install. OS/2 has a different way around this 1024-cylinder limit. If you have an older system which is experiencing problems related to this, check my mini-FAQ on the subject.
OS/2 Warp 3.0 supports most of the common sound cards, including Creative Labs' SoundBlaster series and the MediaVision Pro Audio series of boards. SoundBlaster-compatible cards may or may not work under Warp using the SoundBlaster drivers. Many of the more sophisticated wavetable cards don't yet have good OS/2 drivers available, though most have something, and more have drivers under development. Drivers in one form or another exist for the Advanced Gravis UltraSound boards, the Aztech Waverider 32+, Creative Labs' SoundBlaster AWE32, the Ensoniq Soundscape, OPTi boards (such as the Reveal SC500 rev. 1), Aria-based boards, Mwave-based boards, and others. Turtle Beach has been weak with its OS/2 support, but some models can be made to work in one way or another. Many boards that use an MPU-401 interface can be made to work for MIDI files by using IBM's MPU-401 driver, though it is often necessary to initialize the card in DOS first. Considerably more detail on sound cards can be found in my OS/2 Soundcard Summary.
As mentioned above, multimedia support chews up a substantial amount of RAM under OS/2, and this degrades performance on low-memory systems. Therefore, those with 8MB or less RAM would be well-advised to install without multimedia support. It can be added later, if desired, and also uninstalled, if desired. Disabling WPS sounds for common actions like window opening can help here as an intermediate measure.
OS/2 does not provide direct support for any form of tape drive. There are, however, several packages which allow the use of tape drives under OS/2. These drives fall into five broad categories:
High-capacity removable disks such as Iomega Jaz and Zip drives, SyQuest drives, and magneto-optical disks have been increasing in popularity. These units often connect to a SCSI bus, sometimes to an IDE bus, and often use a computer's parallel port. Devices which use the SCSI or sometimes the IDE bus should work with OS/2 with little trouble, though often with limitations. For instance, it's usually tricky at best to format a removable disk to use HPFS, so you may be restricted to the FAT 8.3 filenames on the removable disk. Drives which connect to the computer's parallel port will require special OS/2 drivers. Iomega provides these for its popular Zip drives, but not in the box; you must contact Iomega to receive this support. The newsgroups have been abuzz with conflicting reports of relative speed of Zip disks under OS/2 vs. other OSes. Most people report worse performance under OS/2, and blame this on uncached OS/2 access to the drives, WPS overhead, poor handling of non-EPP parallel ports, or other factors.
OS/2 3.0 includes support for PCMCIA devices. Unfortunately, I know next to nothing about this topic, and so can say no more about it at this time. [If somebody would care to send me some summary information, I can include it here in the future.] I have, however, received one report to the effect that it's impossible to install OS/2 directly from a SCSI CD-ROM connected to a PCMCIA SCSI adapter.
OS/2's support for printers is generally quite good, in part because there are only a handful of standards for printer command languages (e.g., HP's various PCL levels and PostScript for laser and some ink jet printers, Epson mode for dot-matrix models, etc.). If you get OS/2 and don't find your printer model listed in the (quite lengthy) list of supported models, you can either try a model which your printer is supposed to emulate or contact the printer's manufacturer. Oddly, some printers may actually work better with a driver for a model which the printer is designed to emulate than with a driver labelled as being for the model specifically. This is the case, for instance, with most non-HP 600 dpi laser printers which use PCL 5e; the OS/2 drivers for most of these printers supports only up to 300 dpi, but they often work well with the HP LaserJet 4P driver at up to 600 dpi.
One major exception to the "good OS/2 printer support" rule of thumb is that an increasing number of laser printers are using Windows "GDI" drivers to implement features while minimizing the amount of RAM and CPU power on the printer. Unfortunately, the manufacturers of these printers don't normally include OS/2 drivers, and so the printers will work, at best, with only restricted features (such as 300 dpi printing rather than 600 dpi printing). Some users also report that the OS/2 drivers for many color inkjets produce poor results when printing digitized photos or other complex graphics, relative to the results from Windows. This problem can often be alleviated by using the freeware Ghoscript package in conjunction with an OS/2 Postscript driver set for a color Postscript printer (such as the Postscript version of HP's DeskJet 1200C).
I know relatively little about scanners under OS/2; however, I do know that there are commercial OS/2 programs which support various scanners. There is a web page devoted to providing information about getting HP scanners working under OS/2.
Unfortunately, there's no clear rule that systems from any given manufacturer will or will not run OS/2. All manufacturers change the components used in their computers with such stunning frequency that no generalizations can be drawn. If you're looking for a new system on which to run OS/2, your best bet is probably to get a system with OS/2 pre-loaded. IBM, CompuDyne, Austin, Indelible Blue, and other, smaller firms, sell systems with OS/2 pre-loaded. (There's a new web site devoted to this topic, too.) Try to get a system with the disk formatted at least partially HPFS, if you plan to have OS/2 be your main OS. If you want to purchase from a company which doesn't pre-load OS/2, try to get a guarantee that they will replace any component which doesn't work with OS/2, and check that the brands and models of individual components work with OS/2, as reported here, in the GBU lists, and in Pat Duffy's PCI lists. It might also be helpful to try to get the system with Windows 3.1 rather than Windows 95, since you can then buy Warp "for Windows," which is less expensive than Warp "fullpack."
Under DOS, the "sharing" of interrupts is frequently allowed. This is permitted, in part, because two separate programs are unlikely to try to access two separate devices using the same IRQ at the same time. Such occurrences aren't at all impossible or even uncommon under OS/2, however, and so the sharing of interrupts is much more likely to cause problems under OS/2. One common source of shared interrupts is an internal modem. The default setting for COM3 uses the same interrupt as COM1. The best solution is to reconfigure the modem to use an unused interrupt, or to disable an unused COM port and reconfigure the modem to take on that port's identity (COM number and IRQ). The shareware SIO serial drivers for OS/2 also permit serial port interrupt sharing under some limited circumstances, and so may be a worthwhile investment for those with crowded IRQ lists.
Note that there's no way to determine which interrupts are being used by which components under the standard ISA architecture (and its derivatives), short of physically examining the boards and comparing jumper settings to manuals' listings. DOS's MSD program, which is useful for some things, will give totally inaccurate information on IRQ use, unless your system is relatively "plain vanilla" and therefore conforms to MSD's expectations.
Cruddy hardware abounds, unfortunately. OS/2 pushes the PC's hardware more than does DOS (or even Windows 95), and so will sometimes crash on sub-standard motherboards or RAM chips on which DOS gets by. The cry "it works under DOS" is often heard, but means very little. "It works under Unix" will get more attention, however, since most Unixes push hardware in a way similar to what OS/2 does. Of course, this is not to say that an OS/2 crash must be a hardware issue; like all modern software, OS/2 is not bug-free. Nor should the potential buyer necessarily be scared off if s/he purchased a bargain-basement computer; many of these run OS/2 just fine. This is something to keep in mind, however.
It may be beneficial for the potential purchaser to observe OS/2 running on a system similar to his or her own, particularly in the amount of memory that system has, to determine whether performance is acceptable. OTOH, OS/2 can benefit greatly from performance "tweaks," so observing a poorly-configured OS/2 system may leave the wrong impression.
In general, the hardware issues with OS/2 are very complex. An informed purchaser will research the major components of his or her system before purchasing OS/2, to be sure that OS/2 supports those components. Usually it does, but many people do find one or two components which give problems under OS/2, and this sometimes leads to frustration. If this happens, try posting a calm and rational request for help -- posts with titles such as "Warp Sucks Moldy Lemons" gather more flames than helpful responses.
As to the initial question, the answer must depend upon all of the above hardware issues. Simply put, unsupported hardware adds to the "no" response, while supported hardware adds to the "yes" response. RAM below 8MB pushes towards "no," while RAM of 8MB or more pushes towards "yes." Available hard disk space below 100MB pushes towards "no," while more available disk space supports "yes."