theelf wrote on 2025-02-17, 09:31:The FPU in my benchmarks is almost same as my cyrix 5x86. For example i can get 16fps in my quake test in 5x86@120 build and 34fps in the 266mmhz mediagxm
Yeah, I think overall MediaGX is clock for clock very comparable to 5x86, since it's basically the same core.
jheronimus wrote on 2025-02-17, 10:52:theelf wrote on 2025-02-17, 09:31:The FPU in my benchmarks is almost same as my cyrix 5x86. For example i can get 16fps in my quake test in 5x86@120 build and 34fps in the 266mmhz mediagxm
Yeah, I think overall MediaGX is clock for clock very comparable to 5x86, since it's basically the same core.
I did some test here
Looks like a an NSC Geode GXM-266P CPU the same thing as a Cyrix MediaGXm 266 (GXm-266GP 2.9V ), yes?
And it looks like the boards that support the socketed MediaGXm only support the MediaGXm. Doesn't look like the boards were backwards compatible with other socket5 or socket7 CPU's.
douglar wrote on 2025-02-17, 19:22:Looks like a an NSC Geode GXM-266P CPU the same thing as a Cyrix MediaGXm 266 (GXm-266GP 2.9V ), yes?
And it looks like the boards that support the socketed MediaGXm only support the MediaGXm. Doesn't look like the boards were backwards compatible with other socket5 or socket7 CPU's.
MediaGX socket is only for this line of CPU, and Geode and cyrix are same CPU, but i think just up to gxm, GXLV are different,
GX1 works in my board, but like I said, it’s not faster than GXm
I found a Media GX-266GP 10+ years ago in a box of ceramic CPUs I got from a retired software engineer who was collecting them. At first I thought it was a socket 7 CPU but learned that's not the case after some research. I was fascinated with this chip as soon as I learned it's based on the cyrix 586 core. A 266MHz 586! Fantastic! It took a bit of time 'till I got a motherboard capable of running it - an ECS P5GX-M - off ebay witch I got for 50$, new in box.
I built a system around mine. It even overclocks a bit, it's stable at 9x33MHz. Performance is what you'd imagine a 266MHz 486 with no L2 cache would be. It runs SD-RAM at 66MHz, front side bus is 33Mhz like any other 486. Memory timings are pretty tight and it doesn't seem to loose much performace compared to other 486 class machines with L2 cache, probably due to the faster SDRAM. It can play quake like a 100MHz pentium and it will run Red Alert 95 and starcraft smoothly even with lots of units on screen. It will even run total annihilation. It's not a fast machine but not particularly slow eiteher. On board graphics is... wierd. I've had a few issues with drivers for it. It's pretty slow. On board sound can be pretty buggy - agan, bad drivers. Using the PC with a dedicated PCI video card and an ISA sound card makes it a pretty decent little PC. My machine can be clocked anywhere from 66 to 366MHz, so it can run some speed sensitive games as well as less demanding pentium I era games. Descent, carmageddon, tomb raider, duke 3d - all run great on it. To slow it down I wired a switch to the back of the case witch sets the multiplier to 2x, and then I disable L1 cache. That puts it in the ballpark of a slow 386dx.
douglar wrote on 2025-02-17, 19:22:Looks like a an NSC Geode GXM-266P CPU the same thing as a Cyrix MediaGXm 266 (GXm-266GP 2.9V ), yes?
And it looks like the boards that support the socketed MediaGXm only support the MediaGXm. Doesn't look like the boards were backwards compatible with other socket5 or socket7 CPU's.
Tough physically socket 7, electrically the MediaGX socket is quite different, and NOT pin compatible with socket 5/7 mainboards. Sticking a MediaGX in a regular socket 5/7 motherboard will cause magic smoke (ask me how I know).
Socket3 wrote on 2025-02-18, 21:50:To slow it down I wired a switch to the back of the case witch sets the multiplier to 2x, and then I disable L1 cache. That puts it in the ballpark of a slow 386dx.
Interesting! Could you please share the jumper settings for 2x? I have the same board, but can‘t find a setting like that.
tauro wrote on 2025-02-17, 09:05:I stand corrected! Vanilla FDOOM is slow, FDOOMX is slow... […]
I stand corrected!
Vanilla FDOOM is slow, FDOOMX is slow...But FDM240R is quite fast. 35 FPS! with minor slowdowns (~31 FPS). Full detail. I get 34.1 FPS on DEMO3.
If there are any tweaks that you can think of, please share them.
Try FDOOMVBR.EXE, it uses VESA mode 320x200. In my tests, this is the fastest executable for the Cyrix MediaGX. Not much can be done for this CPU, there is no L2 cache, and there are many bottlenecks due to the 33MHz FSB and shared RAM with the GPU.
EDIT: the Cyrix MediaGX GPU has serious issues with any game using VGA Mode X or Mode Y. Avoid them or use a PCI video card instead.
ViTi95 wrote on 2025-02-27, 09:30:tauro wrote on 2025-02-17, 09:05:I stand corrected! Vanilla FDOOM is slow, FDOOMX is slow... […]
I stand corrected!
Vanilla FDOOM is slow, FDOOMX is slow...But FDM240R is quite fast. 35 FPS! with minor slowdowns (~31 FPS). Full detail. I get 34.1 FPS on DEMO3.
If there are any tweaks that you can think of, please share them.
Try FDOOMVBR.EXE, it uses VESA mode 320x200. In my tests, this is the fastest executable for the Cyrix MediaGX. Not much can be done for this CPU, there is no L2 cache, and there are many bottlenecks due to the 33MHz FSB and shared RAM with the GPU.
EDIT: the Cyrix MediaGX GPU has serious issues with any game using VGA Mode X or Mode Y. Avoid them or use a PCI video card instead.
Thank you for pointing this out.
Can you please tell me more about the limitations of this video chip? I'm stuck with it since the Presario 2200 doesn't have any PCI slots. Are there any workarounds, things worth to try?
Why was it designed this way? was it because they were in a rush, limited budget or lack of knowledge? Is there any info about that?
I'm not familiar with Mode X and Mode Y and I'd like to know what games/software uses each mode.
According to what I read online, Doom, Duke3D, Quake all use Mode X.
While native DOOM performs VERY poorly, Duke Nukem 3D plays fine as far as I could test it.
Quake doesn't do great but it's not so bad with ~21 FPS. So what's going on?
Games like GODS or Cannon Fodder are generally fine, but they occasionally have a flashing artifact. Were it not for that, they would be perfect.
Jazz Jackrabbit runs fine.
Warcraft 2 needs uvconfig and it runs just fine. Even the scrolling speed is fine 😆
tauro wrote on 2025-02-28, 01:10:Thank you for pointing this out. […]
ViTi95 wrote on 2025-02-27, 09:30:tauro wrote on 2025-02-17, 09:05:I stand corrected! Vanilla FDOOM is slow, FDOOMX is slow... […]
I stand corrected!
Vanilla FDOOM is slow, FDOOMX is slow...But FDM240R is quite fast. 35 FPS! with minor slowdowns (~31 FPS). Full detail. I get 34.1 FPS on DEMO3.
If there are any tweaks that you can think of, please share them.
Try FDOOMVBR.EXE, it uses VESA mode 320x200. In my tests, this is the fastest executable for the Cyrix MediaGX. Not much can be done for this CPU, there is no L2 cache, and there are many bottlenecks due to the 33MHz FSB and shared RAM with the GPU.
EDIT: the Cyrix MediaGX GPU has serious issues with any game using VGA Mode X or Mode Y. Avoid them or use a PCI video card instead.
Thank you for pointing this out.
Can you please tell me more about the limitations of this video chip? I'm stuck with it since the Presario 2200 doesn't have any PCI slots. Are there any workarounds, things worth to try?
Why was it designed this way? was it because they were in a rush, limited budget or lack of knowledge? Is there any info about that?
I'm not familiar with Mode X and Mode Y and I'd like to know what games/software uses each mode.
According to what I read online, Doom, Duke3D, Quake all use Mode X.While native DOOM performs VERY poorly, Duke Nukem 3D plays fine as far as I could test it.
Quake doesn't do great but it's not so bad with ~21 FPS. So what's going on?Games like GODS or Cannon Fodder are generally fine, but they occasionally have a flashing artifact. Were it not for that, they would be perfect.
Jazz Jackrabbit runs fine.
Warcraft 2 needs uvconfig and it runs just fine. Even the scrolling speed is fine 😆
The Presario was designed to be non-upgradable.
A few things I never bothered looking at, is
1. Are the 16 bit isa lines still accessible off the chipset somewhere
2. Is the pci bus still there on a chip somewhere (signalling using bodge wires would likely be terrible)
3. Was the 80mb ram limit real or due to bad software/bios?
If Compaq just used a reference design board and left the pci non-routed it may be possible to bodge up a pci slot or bodge a normally surface mounted onboard pci video chip to hack in unintended functionality.
tauro wrote on 2025-02-28, 01:10:I'm not familiar with Mode X and Mode Y and I'd like to know what games/software uses each mode.
According to what I read online, Doom, Duke3D, Quake all use Mode X.
The dosbox-staging wiki has an informative page listing some more - it's not comprehensive, but it's a good start:
https://github.com/dosbox-staging/dosbox-stag … emulation-tests
There's several emulators for DOS up until ~1998 that also use Mode X extensively. From what I recall, Baryon is another example. Duke3D does not use Mode X.
Quake doesn't do great but it's not so bad with ~21 FPS. So what's going on?
I'm going to assume that you're referring to 320x200 - by default, when you select 320x200 in the resolution options in Quake it will set vid_mode 0 which is 320x200 13h, while vid_mode 1 is 320x200 Mode X which can only be set via the console. Some VESA cards can also 320x200 in Quake, but you'll need to type vid_describemodes to get the correct list, as some cards will organise VESA modes in some weird arbitrary order. A good number of them will use vid_mode 11, but a Geforce 2MX will use vid_mode 16 as one example I can think of. Phil's Benchmark Pack is remarkably unreliable with its "640x480" option, since vid_mode 12 can mean anything, more often than not it'll actually be 320x240. I strongly doubt Phil bothered to test it with anything that wasn't from Nvidia.
Warcraft 2 needs uvconfig and it runs just fine. Even the scrolling speed is fine 😆
WC2 uses VESA, and VESA is not Mode X.
tauro wrote on 2025-02-28, 01:10:Thank you for pointing this out. […]
ViTi95 wrote on 2025-02-27, 09:30:tauro wrote on 2025-02-17, 09:05:I stand corrected! Vanilla FDOOM is slow, FDOOMX is slow... […]
I stand corrected!
Vanilla FDOOM is slow, FDOOMX is slow...But FDM240R is quite fast. 35 FPS! with minor slowdowns (~31 FPS). Full detail. I get 34.1 FPS on DEMO3.
If there are any tweaks that you can think of, please share them.
Try FDOOMVBR.EXE, it uses VESA mode 320x200. In my tests, this is the fastest executable for the Cyrix MediaGX. Not much can be done for this CPU, there is no L2 cache, and there are many bottlenecks due to the 33MHz FSB and shared RAM with the GPU.
EDIT: the Cyrix MediaGX GPU has serious issues with any game using VGA Mode X or Mode Y. Avoid them or use a PCI video card instead.
Thank you for pointing this out.
Can you please tell me more about the limitations of this video chip? I'm stuck with it since the Presario 2200 doesn't have any PCI slots. Are there any workarounds, things worth to try?
Why was it designed this way? was it because they were in a rush, limited budget or lack of knowledge? Is there any info about that?
My guess is that they focused on performance for VESA modes, as they are faster and easier to work with. All other modes were merely emulated for backward compatibility.
douglar wrote on 2025-03-09, 13:04:How is the sound blaster compatibility on the MediaGX?
How does it compare with the Advanced Logic ALS100 Plus?
DIAGNOSE.EXE Version 4.04 detects it as DSP version: 4.12 and everything is detected correctly and it's working fine. All the programs and games I tried worked well.
On the Presario 2200 the PC speaker is directly routed to the sound card and it sounds quite good. That's a plus.
I would check compatibility with SB Pro if I knew which software or games I should try.
ViTi95 wrote on 2025-03-09, 13:10:My guess is that they focused on performance for VESA modes, as they are faster and easier to work with. All other modes were merely emulated for backward compatibility.
I see. It shows a lack of seriousness and commitment. But probably the budget was low.
I can't understand how you can emulate older modes and if there's a way to change the way that older modes are emulated. Could it be done with a TSR? The video card is far more capable and it's disappointing that it's glitchy with such basic stuff.
Here's a demo of what the bug looks like. I let the demos of The Lost Vikings run and recorded it.
Most of the time, everything is fine. But sometimes, it could take 30 seconds or 5, an image from a different place of the level appears (from a different region of memory?). It briefly appears and disappears. This happens all the time with many games, but not all. So they are playable, but it gets annoying.
Some important bits of info: the same demo doesn't always glitch in the same part. I think this may be significant.
Example 1
Frame 1
Frame 2
Frame 3
Example 2
This time it goes one way and then the other way, before it returns.
Frame 1
Frame 2
Frame 3
Frame 4
Example 3
Frame 1
Frame 2
Frame 3
rmay635703 wrote on 2025-02-28, 04:37:The Presario was designed to be non-upgradable. […]
The Presario was designed to be non-upgradable.
A few things I never bothered looking at, is
1. Are the 16 bit isa lines still accessible off the chipset somewhere
2. Is the pci bus still there on a chip somewhere (signalling using bodge wires would likely be terrible)
3. Was the 80mb ram limit real or due to bad software/bios?If Compaq just used a reference design board and left the pci non-routed it may be possible to bodge up a pci slot or bodge a normally surface mounted onboard pci video chip to hack in unintended functionality.
It would be very interesting to find this out. It would be such a cool hack! Even a 16-bit ISA would mean a lot for this machine.
tauro wrote on 2025-03-18, 17:49:ViTi95 wrote on 2025-03-09, 13:10:My guess is that they focused on performance for VESA modes, as they are faster and easier to work with. All other modes were merely emulated for backward compatibility.
I see. It shows a lack of seriousness and commitment. But probably the budget was low.
I can't understand how you can emulate older modes and if there's a way to change the way that older modes are emulated. Could it be done with a TSR? The video card is far more capable and it's disappointing that it's glitchy with such basic stuff.
Basically they use the CPU for certain operations, which slow everything down. There isn't much more information about how it really works. Also seems not everything is 100% implemented.
