The RAM is counted as 8 bit, one byte wide chunks, so there's two side by side in a 16bit chip, so you're seeing 4 times 512 kilobyte chips on there, so you have 2MB installed. Buying four more of the original part number will give you 4MB total.

My card that I just found yesterday has VT51264 parts on it, which should also be suitable, but since you've found matching ones you probably don't wanna let them get away.

edit: sorry VT514264 ... those seem to be in demand for fixing voodoo 1s so probably not a cheaper option.

RagingSquirrel wrote on 2024-02-19, 19:14:

Hi […]
Show full quote

Hi

I am in the process to build a 486 rig. I have a S3 Virge pci videocard. With emplty ram expansion slots..Wich i would like to populate. I searched the forum, and i found an older post where someone linked az aliexpress link claimed that these chips would work with all types of s£ Virge card.

Here is the link :

https://www.aliexpress.com/item/4000117049156 … 7Cquery_from%3A

Here is a picture from my card

As far i understand instead of the 2MB i have the 1 MB original S3 Virge card..so my question is would these chips work on my card?

I also found the exact same chips that i have on my card on e bay.. here :

https://www.ebay.co.uk/itm/165775944703?mkcid … emis&media=COPY

If both of these chips would work, which one would be better in my case. Because the second one would be more expensive, and if i understand correctly the first one would add 2MB and the last one only 1MB ...

The card (as already mentioned) has 2MB, you can upgrade it to 4MB.
Serious question: Why do you want to upgrade the card?
Definitely there will be no speed gain, you already have the full 64bit bus to the graphics card's memory.

Well tbh i taught there's gonna be a slight performance boost, if i max out the ram. Also i want to built a maxed out rig.. That's why i upgraded to 512k cache as well on the mobo...
I don't really understand why it wouldn't speed up the card? I taught more ram equals more speed xD also why is that an option if it aint gonna make it better.. ?

To simplify, like CoffeeOne mentions, the extra chips will be wired "in series" rather than "in parallel", so there won't be extra memory bandwidth available to the card even if you add more RAM.

I have a S3 ViRGE ST-325A that has 4MB of RAM:

It supports the following VESA resolutions in that configuration:

You can try running SNOOP.EXE: (S)VGA adapter info tool and CRT Terminator config utility on your system to see what resolutions the 2MB variant support, and maybe expanding the RAM will cover the difference.

The chips for each missing slot each hold 512KB of RAM.

On another S3 Trio64V+ card I have these kind of slotted memory:

and I see there are 2x OKI M514265BSL-60J chips expanded there. I believe these are "262,144-Word x 16-Bit FPM (Fast Page Mode) EDO" DRAM in SOJ40 (Small Outline J-Leaded) packaging.

The "-50JC" text on the other RAM chips on your card say that the existing memory has a 50 nanoseconds latency. So you would want to acquire chips that have as good latency as well.

I believe for example these chips would be compatible: https://www.ebay.com/itm/323298517198 (the number 5 at the end should mean 50 nanoseconds), although I make no guarantee - you may want to google for some data sheets to double confirm.

RagingSquirrel wrote on 2024-02-20, 09:23:

I taught more ram equals more speed xD also why is that an option if it aint gonna make it better.. ?

Btw, even on modern PCs, if you have a 2 memory channel system and you add 4 sticks of RAM, then it will limit the max bandwidth of the system. It is a common problem that people get that their motherboard might support overclocked RAM up to, say, 5600 MHz, but that limit might only apply to if you have 2 memory sticks, and if you populated all four, the max supported RAM clock speed might go down to e.g. 4800 MHz.

That kind of behavior doesn't happen with this vintage card, but just to illustrate that even in modern environments more RAM does not at all mean more speed. The sweet spot is when you have all the memory channels populated so you don't leave any unused, but don't stack up many "ranks" of RAM inside a single memory channel, which is what causes a slowdown.

RagingSquirrel wrote on 2024-02-20, 09:23:

Well tbh i taught there's gonna be a slight performance boost, if i max out the ram. Also i want to built a maxed out rig.. That's why i upgraded to 512k cache as well on the mobo...
I don't really understand why it wouldn't speed up the card? I taught more ram equals more speed xD also why is that an option if it aint gonna make it better.. ?

More speed? You taught wrong!

Speed is only improved if it enables interleaving, which is not the case here, the 2MB you already have utilizes the full bus bandwidth, so adding more won't change anything. The reason to add RAM is to increase available video modes. 2MB allows 800x600@24b or 1024x768@16b. Doubling that to 4MB allows 1024x768@24b, which is a huge improvement under Windows 3.x or 9x.

In DOS there's basically nothing out there that uses more than 800x600@8b, which needs less than 1MB. Adding more will not change anything.

If you upgrade, be sure to at least match chip speeds. These are 50ns parts, so get 50ns or lower.

dionb wrote on 2024-02-20, 11:13:

In DOS there's basically nothing out there that uses more than 800x600@8b, which needs less than 1MB. Adding more will not change anything.

Tomb Raider in S3D mode runs at 640x480x16bpp and will benefit from 4MB.

Not sure how much performance will improve, but you do get a bit more detail with 4MB, including Lara's shadow properly showing up.

okay .. so i frazed it wrong , what i menth that i thaught more ram would improve the performance....

dionb wrote on 2024-02-20, 11:13:

Speed is only improved if it enables interleaving, which is not the case here, the 2MB you already have utilizes the full bus bandwidth, so adding more won't change anything. The reason to add RAM is to increase available video modes. 2MB allows 800x600@24b or 1024x768@16b. Doubling that to 4MB allows 1024x768@24b, which is a huge improvement under Windows 3.x or 9x.

Ok so if i want to run Win 95 in 1024*760 32 bit i shoud upgrade right? And for Dos games it really doesnt matter

clb wrote on 2024-02-20, 09:57:

I believe for example these chips would be compatible: https://www.ebay.com/itm/323298517198 (the number 5 at the end should mean 50 nanoseconds), although I make no guarantee - you may want to google for some data sheets to double confirm.

Thank you, but these chips are more expensive than what i found. (Te exact same chips that i have on the board already :https://www.ebay.co.uk/itm/165775944703?mkcid … emis&media=COPY )

Joseph_Joestar wrote on 2024-02-20, 11:18:

dionb wrote on 2024-02-20, 11:13:

In DOS there's basically nothing out there that uses more than 800x600@8b, which needs less than 1MB. Adding more will not change anything.

Tomb Raider in S3D mode runs at 640x480x16bpp and will benefit from 4MB.

Not sure how much performance will improve, but you do get a bit more detail with 4MB, including Lara's shadow properly showing up.

Ooh that's a great point. Of course this S3 ViRGE graphics card is new enough to have 2D and 3D acceleration, so workloads that utilize GPU surfaces and 2D GUI blitting from such surfaces, or 3D texturing or framebuffers can benefit from the added capacity.

RagingSquirrel wrote on 2024-02-20, 12:18:

Thank you, but these chips are more expensive than what i found. (Te exact same chips that i have on the board already :https://www.ebay.co.uk/itm/165775944703?mkcid … emis&media=COPY )

Nice, that's a better find for sure.

Joseph_Joestar wrote on 2024-02-20, 11:18:

dionb wrote on 2024-02-20, 11:13:

In DOS there's basically nothing out there that uses more than 800x600@8b, which needs less than 1MB. Adding more will not change anything.

Tomb Raider in S3D mode runs at 640x480x16bpp and will benefit from 4MB.

Not sure how much performance will improve, but you do get a bit more detail with 4MB, including Lara's shadow properly showing up.

I don't think the extra RAM will get you extra performance, because IIRC games at that time generally did not swap out textures in-frame due to performance concerns.

On the other hand, at 640x480, a single frame buffer will occupy 600KB. You generally want double-buffering (Z-buffer usually not required) for early 3D accelerated games, so that's 1200KB for the active rendering buffer (600KB for the next frame) and the currently displayed buffer (600KB for the current frame), leaving a measly 848KB for textures. This is quite low memory, and it makes sense that games reduce graphics features (like Lara's shadow) if that's all. The extra 2MB will be fully usable for textures, so at 4MB, there are 2896KB for textures, which is more than thrice you had before. So clearly: You can get more detail, possibly using some higher-resolution textures or by adding textures that were completely skipped in the 2MB mode, but the rendering of extra graphics features will be more work for the card, so if the frame rate changes at all, it will go down due to the increased workload and not go up due to the advantage of more memory. OTOH, 640x480 on a Virge, especially at the stock clock of the original Virge (86c325) is quite ambitious. In my oppinion, game designers trying to use the chip in that mode instead of 512x384 (which could be displayed at 1024x768 interlaced timing with half the pixel clock and without interlacing, so monitor support would be great) is one of the reasons the 3D acceleration feature of the classic Virge got the bad reputation as "3D decelerator".

RagingSquirrel wrote on 2024-02-20, 12:18:

Ok so if i want to run Win 95 in 1024*760 32 bit i shoud upgrade right? And for Dos games it really doesnt matter

Go ahead with the upgrade. Anyway this card is "3D accelerator" just on paper, but whit 4 MB of VRAM you can use higher color depth in high resolution 2D modes and S3 ViRGE has excellent DOS compatibility.

EDIT: This could have been a limitation of my specific card at the time, linked to either clock speed or RAM speed.

EDIT2: According to my understanding of https://www.vogonsdrivers.com/getfile.php?fileid=326 , this limitation is documented in the datasheet . IL means interlaced, AFAIU.

AFAICR, a 4MB Virge 325 will not do 1024x768 at 24 or 32-bit color at even 60Hz progressive (non intetlaced) in 2D. 87Hz interlaced is all you get and that mostly requires a CRT ( most LCD screens will not handle that) and it is an eyesore, IMHO.

The Virge 325 handles overclocking quite well. The standard 50MHz chip/memory clock can be tuned up to 75-80MHz on a lot of '325s. This would likely yield enough memory bandwidth to run the modes non-interlaced that are specified as "interlaced only" in the data sheet. You would need a modified BIOS to set them, though. The good news is that the Virge driver for Windows 95 does not program any modes itself, so getting non-interlaced 4MB modes can be implemented using a TSR loaded from autoexec.bat that intercepts INT 10h.

mkarcher wrote on 2024-02-20, 19:37:

The Virge 325 handles overclocking quite well. The standard 50MHz chip/memory clock can be tuned up to 75-80MHz on a lot of '325s. This would likely yield enough memory bandwidth to run the modes non-interlaced that are specified as "interlaced only" in the data sheet. You would need a modified BIOS to set them, though. The good news is that the Virge driver for Windows 95 does not program any modes itself, so getting non-interlaced 4MB modes can be implemented using a TSR loaded from autoexec.bat that intercepts INT 10h.

I was actually able to get 60Hz to work unreliably (intermittently) at 1024x768 in 24-bit under Windows 95 back in the day using Powerstrip. I do not remember exactly what I did back then (and TBH, I was more clueless than I am now anyway). So it is possible to do this. How reliably it can be done is another question.

EDIT: I may or may not have been using MCLK (by Royce Liao) or something similar.

IDK why but my brain goes, "You need bare minimum 4MB for DX5, 8MB for DX6, 16MB for DX7 ... "

BitWrangler wrote on 2024-02-20, 23:20:

IDK why but my brain goes, "You need bare minimum 4MB for DX5, 8MB for DX6, 16MB for DX7 ... "

Unless one is at least a bit of a masochist, DX5 or higher on a Virge is not fun, no matter which chip variant, clock speed or amount of video RAM one has.

You totally need 4Mb to play 3D stuff with any semblance of performance.