There are no safety issues, i.e the hardware will not get damaged although if there is instability and you have VLB connected IDE, there is room for data corruption so maybe it is better to do some testing from boot floppy instead. Two VLB cards at 40MHz shouldn't be a problem, and if 0WS will work it will be even better. I run two VLB cards at 50MHz with 0WS on one 486 I got so this is definitely doable.

If things will work without stability issues depends on the motherboard and cards you are going to be using, they are not created equal and only way to find out is to try.

Awesome. I'm happy with that, time to experiment hehe.

As a kid I was super poor and only had crap gear. It's amazing to delve into this all these years later with actual good equipment.

I don't know how reliable this article is which says:
"The VESA local bus [..] had a problem. At 33 megahertz, it could handle three cards. At 40 megahertz, it could handle two cards. [..] At 50 megahertz, it could only handle one card."

I'm running Cirrus 5434 VLB and VIA IDE VLB both @50Mhz with Cx5x86/100 (2x50MHz) and no problems.

As a rule of thumb using more than one VLB card at 0WS at 40MHz or higher FSB is hard and if one of them is an IO card expect weird behaviour and corruption.

Yes it can work without risks for the hardware, but 2 cards at 40MHz is marginal and heavily depends on the cards and motherboard. Definitely not unheard of, but as others already wrote reliability and stability issues are possible. Corruption is especially nasty as it won't always manifest right away in trials. I'd say experiment with it and enjoy the trip.

Sweet deal. Thanks everyone for the feedback.

As my only writeable media is a compact flash card that I can pretty easily repopulate with necessary content, I think I’ll take the risk running @40mhz with 0 wait states and see how things go. Hey, what could go wrong! 😜

The only weird thing I did notice is that my VLB IO card has a jumper for 33mhz or 50mhz, but not 40mhz. I guess I’ll put it at 50mhz? 🤷

Maybe the 50mhz setting just compensates for higher speed by adding some sort of safety mechanism. Who knows. I may just be making things up at this point hehe.

Yeah, the higher speed jumper is usually a wait state jumper. On cards I have, putting it to the higher speed makes everything slower, but you got to experiment.

HanSolo wrote on 2023-06-14, 23:33:

I don't know how reliable this article is which says:
"The VESA local bus [..] had a problem. At 33 megahertz, it could handle three cards. At 40 megahertz, it could handle two cards. [..] At 50 megahertz, it could only handle one card."

It's been stated many times in the past, but I'll mention it again. These are the VLB 2.0 specifications. VLB 2.0 was practically not implemented. From what I heard, maybe only the OPTi 895 chipset and CL GD5434 made any attempt to implement it.

The specifications for VLB 1.0 (which is almost without doubt what you have) is three cards at 25MHz, two cards at 33MHz, a single card at 40MHz and at 50MHz only a single device can be integrated into the motherboard.

In practice, what you are actually able to achieve comes down to the design of your motherboard and daughter cards. As mentioned, 0WS 50MHz SVGA is doable with good quality components. Having more than two VLB cards installed at any given time is pretty rare.