First post, by Hoping
Lately I've been spending time with two Chinese Rage XL PCI graphics cards looking to get the most out of them as they are very reasonably priced leaving a bit of room for improvement.
Well, the first and most important problem many owners encounter is that these graphics cards won't boot on AT rigs that don't have the 3.3v PCI slots.
My solution that is not totally original,
(something like this has already been seen in a youtube video https://www.youtube.com/watch?v=Gbyv4wI0v0s but it did not seem like a completely clean and functional solution)
I used an AMS 1117 3.3v regulator with its respective capacitors for the video RAM memory and a step down module based on the XL4005, which requires a minimum of 5v input, to power the graphics processor and adjust its voltage to the one indicated in the data sheet of the Rage XL which is 2.5v.
For this removed the P3055LD mosfet, and to make these graphics cards fully compatible with any PCI slot cut the 3.3v power pins so that now it only feeds from the 5v pins and so I tested them both in PCI slots with 3.3v and PCI slots that only supply the 5v and they worked correctly, although the older motherboards I have are for Pentium (430vx, 430FX and 430TX) unfortunately I can't test them on any 486 motherboard with PCI.
A curious detail is that in the two graphics cards that I modified the graphics processor was receiving 3.3v instead of 2.5v.
The next thing was the attempt to overclock, the only program that I found that could do something with these graphics cards was Powerstrip, although unfortunately I was only able to overclock the video memory and although an important improvement is achieved, it is not all that I would like.
In the case of the first graphic card, the newest one bought a few months ago, it is equipped with an SDRAM chip marked for 7ns(143mhz) and it goes up correctly from 84mhz to 143mhz although it needs 3v for the graphic processor, this increases the performance in GLQuake from 21fps to 34.5fps and in 3DMark from 906 to 1167 points.
My next objective would be to overclock the graphics processor since I imagine that even a small overclock of 10mhz would be quite noticeable but here I don't have enough knowledge, I wonder if the BIOS could be modified or the graphics card could be physically modified.
As for the BIOS, I found this program (https://www.techpowerup.com/download/ati-flashrom/) that works correctly with these graphics cards.
I tried to flash the BIOS of an original Rage XL PCI that I found on this web page http://www.vgamuseum.info/index.php/cpu/item/108-ati-rage-xl but with that BIOS the Chinese version does not shows image although the computer does start.
I would like to ask for help regarding the overclock issue, if someone would know how to modify the BIOS or the card to overclock the graphics processor.
I enclose the BIOS of each of the graphics cards that I have modified.
EDIT: forgot to mention the specs of the computer I'm using for this tests.
DFI G586IPV 512K
K6-2 400CXT 6*66 at 2.5v
64MB RAM (mixed 32mb EDO and 32mb SDRAM)