I'm not intimately familiar with either card, but it's likely a limitation of the controller on the SIIG (it itself cannot do >65k) than a memory capacity limit.

Cirrus Logic made budget graphics chips. I remember the 2MB upgrade on a lot of the low end cards being almost useless. I think the ARK1000 cards are like this as well. But you're right, 2MB should be enough to do 16 million colours at 800x600. My advice would be to upgrade to a better card. The CL 5434 for example.

http://www.vgamuseum.info/images/stories/doc/ … s/cl-gd542x.pdf
Looks like the only thing 1 to 2MB gets is 256C @ 1280x1024 it only does 16M at VGA 640x480

Unclear if this generation of cards did anything clever with extra memory

Matth79 wrote:

Unclear if this generation of cards did anything clever with extra memory

Until now I thought that resolution/color setting is just a matter of memory and drivers. Are we sure that it's not a matter of available drivers and that really some cards can't output (by design restrictions) every possible color setting at supported resolutions that memory permits? If this is the case, then I also want to learn more about the quoted sentence above.

konc wrote:

Matth79 wrote:

Unclear if this generation of cards did anything clever with extra memory

Until now I thought that resolution/color setting is just a matter of memory and drivers. Are we sure that it's not a matter of available drivers and that really some cards can't output (by design restrictions) every possible color setting at supported resolutions that memory permits? If this is the case, then I also want to learn more about the quoted sentence above.

That's what I've always thought, too. This is really puzzling. The strange part is that in NT 3.51, I get a maximum of 256 colors at 800x600, but in Win 95 and DOS/3.x, I get 64K colors at 800x600, even though I should be getting 16 million on all three operating systems.

So it makes me wonder, is it a driver issue, or is the OS imposing some sort of limitation on the card's memory space, or what? Why would the driver not support more colors at higher resolutions?

Matth79, thanks so much for the link! That's really good info. If it indeed is a limitation of the chip itself, that's just so ridiculous! Oh well, we take what we can get.

My ATI Graphics Pro Turbo boasts 16 million colors at 1280 x 1024 with 4mb RAM but according to the box uses a dithering technique at that resolution. It will do it without resorting to any trickery in 1024 x 768 though. The box for my Graphics Xpression says it can do 16 million colors at 800 x 600 with 2mb.

The Windows NT colour limitation is almost certainly a driver issue. Are you using the driver that came with NT? If so, get a 3rd party driver. Maybe the pack in driver is one that supports a broad range of CL cards and only supports common features.

WhatANerd wrote:

That's what I've always thought, too. This is really puzzling. The strange part is that in NT 3.51, I get a maximum of 256 color […]
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That's what I've always thought, too. This is really puzzling. The strange part is that in NT 3.51, I get a maximum of 256 colors at 800x600, but in Win 95 and DOS/3.x, I get 64K colors at 800x600, even though I should be getting 16 million on all three operating systems.

So it makes me wonder, is it a driver issue, or is the OS imposing some sort of limitation on the card's memory space, or what? Why would the driver not support more colors at higher resolutions?

Matth79, thanks so much for the link! That's really good info. If it indeed is a limitation of the chip itself, that's just so ridiculous! Oh well, we take what we can get.

Why is it puzzling? It sounds like it's behaving exactly as the documentation says it will - a maximum of 65k color output (based on your original post). Resolution/color-depth is not exclusively related to how much RAM you have - just like my GeForce FX with 128MB cannot do 30-bit color, despite having enough memory for it (and is that "so ridiculous"?).

The limit in 3.51 is likely OS/driver related though - I'd just pick a different operating system or card if you need higher resolutions and color depths for your application (either under 3.51 or in general).

I've used a FX5200 128mb in 1920x1080x32 before just fine. Is there something i'm missing here?

leileilol wrote:

I've used a FX5200 128mb in 1920x1080x32 before just fine. Is there something i'm missing here?

😊 I said 30-bit color, as in billions of colors ("deep color")."32-bit color" refers to 24-bit + 8-bit alpha; you're still only drawing from a palette of 16.7M colors ("true color"). Very few consumer cards/devices can deal with 30-bit, even though many of them since at least the GeForce FX era have had sufficient memory to do so - in many cases it's both a hardware and software limitation. A notable exception to this is the Matrox Parhelia, which has 10-bit controllers/RAMDACs. Various professional cards, especially more recent models, also support the feature. True 10-bit LCDs are also relatively rare, and generally quite expensive too.

My point was to use it as an example - there are cards with more memory than a Parhelia (like FX 5950, for example), but that do no support the same resolution/color-depth/etc modes due to hardware and/or software limitations.

Yeah, I guess so. It's just puzzling because I've just never heard of or seen such a thing, and I've been around my fair share of systems. I had a few cheapie VLB cards in the '90s and they were all able to do 24bit at 800x600. One was a Diamond Speedstar Pro, which as a poor kid I recall being more of a low-end card. Hmm, actually I just looked it up and the Speedstar Pro VLB used a CL5428! I must have had the Speedstar Pro SE then, which used a CL5430.

I just figured that any VLB card would (should!) be able to pull it off, especially since the box brags about 16.7 million colors and supporting a 50MHz bus speed. Good thing I got this SIIG card NIB for free; had I paid for it back in the '90s I'd be one unhappy customer! "SIIGnificantly better" my butt!

I've been hunting for NT 3.x drivers for the 5429 to no avail, unfortunately.

WhatANerd wrote:

Yeah, I guess so. It's just puzzling because I've just never heard of or seen such a thing, and I've been around my fair share of systems. I had a few cheapie VLB cards in the '90s and they were all able to do 24bit at 800x600. One was a Diamond Speedstar Pro, which as a poor kid I recall being more of a low-end card. Hmm, actually I just looked it up and the Speedstar Pro VLB used a CL5428! I must have had the Speedstar Pro SE then, which used a CL5430.

I just figured that any VLB card would (should!) be able to pull it off, especially since the box brags about 16.7 million colors and supporting a 50MHz bus speed. Good thing I got this SIIG card NIB for free; had I paid for it back in the '90s I'd be one unhappy customer! "SIIGnificantly better" my butt!

I've been hunting for NT 3.x drivers for the 5429 to no avail, unfortunately.

It's honestly not surprising to see such a limitation on a Cirrus card; I remember having a PCI-based model in the mid 1990s that had pretty limited color/resolution options (if I remember right it was limited to 15-bit (32k) over 800x600 or something odd like that). It was functional/stable, but not the greatest in terms of quality.

Don't think I can be much help with NT 3.51 - I've never had good luck with that operating system. 😒