Assessment of Video Cards with OS/2 2.x Support

if the machine had 16 Mb or more of RAM. Well, I'm in the market for a video card too and have an ISA machine with 20Mb of RAM and was wondering what a memory aperature was and what problems the high memory caused.
 * In one of your posts in OS2DF1 you mentioned that some video cards need a memory aperature on ISA machines and that this was a problem

The problem seems to be limited to the ATI Ultra Pro (VRAM) and Ultra Plus (DRAM) and (I think) the P9000 (Diamond Viper). For best performance they need a linear memory aperature of at least 2Mb that is 2 Mb above all physical RAM (which must be contiguous). On an ISA bus that aperature must be below the 16Mb line because of addressing limits on the ISA bus. That means the memory aperature can't be used with more than 12 Mb of RAM. An (expensive) EISA card solves the problem. (Having an ISA card in an EISA slot doesn't help.) VESA Local Bus (VLB) apparently doesn't solve the problem either, at least on the ATI.

BTW, I don't think the memory aperature affects the performance using IBM's 8514/A drivers, only ATI (Windows and presumably Windows NT beta) drivers. However, the Ultras are slower and more limited in 8514/A mode than they are with native ATI drivers. Then again, ATI has yet to release even 16-bit drivers for OS/2 (they're in beta), and the release of 32-bit drivers is probably at least 3 months away. Note also that ATI is known for buggy drivers.

One advantage of ATI is that the Mach32 chip has hardware support for Windows motion video playback; it's unknown whether this will be available for OS/2. Also, although ATI prices have been high, it slashed prices 30% last week.


 * Do you know much about it or know where I can find that information?

GO ATITECH and scan the messages. In short, ATI claims only a 5% slowdown when the memory aperature is disabled, but there have been several reports of big performance losses and an inability to use 24-bit color; ATI's response is that it is still working on optimizing its Mach32 drivers. GO DMNDONLINE for Diamond information. (Tseng ET4000W32 information is available in the same forum.)


 * Also, if you've made a purchase yet, which card did you decide on?

From all that I've learned, the choices as I see them (in increasing order of performance and to some degree cost) are:


 * CatsEye/X: An ISA XGA-2 card using the IBM chipset that probably has the best driver support by far under OS/2 2.1.  Speed is reportedly good, but not as fast as the latest S3 accelerators, not to mention the Weitek P9000.  Color depth is limited to 8 bits (static 64K color pallette).  $250 + $9 shipping by mail order.


 * Diamond Stealth 24 (S3 801/805 w/DRAM) or equivalent (e.g., Orchid): S3 is well-supported in drivers in most environments -- there are already generic NT beta drivers and soon to be generic OS/2 drivers. Both Diamond and Orchid release their own tuned drivers, which are expected in a month or two. The 801/805 cards are a good deal faster than the old fast S3 911/924 cards (even unaccelerated), and are a real bargain thanks to the use of 1 Mb DRAM (about $170 on the street).  Both ISA and VLB versions.  24-bit color in 640x480, 16-bit (64K) color at 800x600, and 8-bit (256) color at 1024x768. VESA-standard refresh rates at all resolutions.


 * Diamond Stealth Pro (S3 928): A bit faster than the S3 801/805, but quite a bit more expensive (about $250 on the street with 1 Mb) due to the use of VRAM; the speed difference only really shows up at the highest resolutions (up to 1280x1024) and refresh rates (VESA-standard at all resolutions).  Upgrade to 2 Mb ($80-100) allows 24-bit color in 800x600, 16-bit (64K) color at 1024x768, and 8-bit (256) color at 1280x1024.


 * Tseng ET4000W32 (a few smaller suppliers and the Hercules Dynamite expected soon): Fastest DOS and dumb frame buffer performance, and accelerated Windows performance is claimed (unsubstantiated) to be faster than the S3 801/805 and even comparable to the P9000.  The best non-accelerated driver support of any card, but accelerated drivers for OS/2 are at least 2-3 months away (currently in early alpha); likewise NT.  Also a real bargain, with prices about the same as the S3 801/805.  However, VESA 70+ Hz refresh rates are only supported (by the Hercules) at up to 8-bit (256) colors; 16-bit (64K) and 24-bit (16M) color are limited to 60 Hz.  Bear in mind that even a dumb frame buffer like the Tseng ET4000 performs much faster on VLB than on the ISA bus, giving perhaps 2/3 of the speed boost of an ISA bus S3 accelerator (though much less than a VLB accelerator), so a VLB Tseng ET4000W32 should give at least respectable performance even without accelerated drivers.


 * Diamond Viper (Weitek P9000) or equivalent (e.g., Orchid): This is a screamer, about 40% faster than the S3 928 as measured by WinBench 3.11, although the real world performance difference is smaller. Plays enlarged motion video at 800x600x64K effortlessly (as tested on a DX2-66).  Thanks to top performance and 2 Mb of pricey VRAM (resolutions up to 1280x1024x256, all at VESA-standard refresh rates), at the moment it's about $400 or more on the street.  OS/2 drivers are in alpha (shown by Diamond last month at COMDEX and just made available for download by Orchid) and also due to be released in 1-2 months; NT drivers are supposed to be out in about the same time frame.  Early cards were a bit buggy, so be sure to get the latest rev (chipset and BIOS).


 * IIT X-14 (Hercules Graphite) and X-15 (Orchid Celcius). The X-15 (an improved version of the X-14) is claimed by IIT to be the fastest current accelerator.  (Orchid confirms that it is a bit faster than the P9000, which Orchid also sells.)  However, OS/2 driver support is very limited -- only 800x600x256 and 1024x768x256 alpha drivers for the X-14 (that don't support the X-15), with no word on when more drivers will be made available.  The X-14 and X-15 are NOT fully XGA-compatible, so XGA drivers won't work.  Another problem is that the VLB version of the Hercules Graphite is only FCC Class A.

My research has convinced me that WinBench is NOT an accurate predictor of real-world performance. Certain chips and/or drivers have been optimized to win the WinBench contest without providing as much real-world performance as the numbers would suggest. Caveat Emptor.

The bottom line is that *any* of these cards (even the ISA ATI) are reasonable choices, depending on what you want and what you can afford. If I were going to run OS/2 all the time and I wanted the best possible support, I'd go with the CatsEye/X. If I wanted to run *anything*, I'd go with the Tseng ET4000W32. If I wanted the best bang for the buck I'd go with the S3 801/805. If I wanted the absolute top performance (and could afford it), I'd go with the Weitek P9000, IIT X-15, or maybe settle for the S3 928.

I haven't made a final personal decision yet -- I'm agonizing between the Orchid F1280+, P9000 and X-15.

John Navas 70244,2046 6/3/93