For ISA, eh? Unfortunately you can't have an ISA card that is fast and both DOS and Windows it seems. DOS likes DRAM, and Windows likes VRAM. But, I am assuming you are asking about mostly about speed under DOS games. I have heard that the Mach64 DRAM card is pretty quick. I've only used the VRAM version myself which is just okay...but this is an ISA card afterall. One of the things I have heard that is great about the ISA mach64 cards is that you can overclock the hell out of them...like 20MHz on an ISA bus. That works out great so long as you have other cards on the bus which can also handle the speed, but in reality it's pretty much almost impossible to do, especially if you want to run an ISA soundcard as well.
Cirrus Logic cards are usually okay under DOS, but I have heard the CL-5434 based cards are better than average.
One card I have heard is really great but have never used is based on the Tseng ET4000W32i chipset. Those are pretty hard to come by.
I think there are a few ISA cards out there based on S3-864, and those should be similar to the Mach64 DRAM.
I could be wrong, but I am pretty sure there were no ARK based ISA cards.
Anyway, unless you can find this Tseng card I mentioned, I think you're best off with your Mach64.
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