For what it's worth, a pure GeForce 2MX is pretty much the same as an MX400 (although, yes, it usually has a lower core clock - 175 MHz compared to 200 MHz on the MX400).
However, this makes very little difference in most situations, since both cards are memory bandwidth starved (166 MHz memory clock @ 2.6 GB/s bandwidth), so they hit the memory bandwidth bottleneck before they actually hit a fill rate bottleneck.

Furthermore, all GeForce 2 MX cards with a core clock of 175 Mhz that I tested work fine at 200 MHz (usually much more - like 220/230).

That being said, although you won't notice a difference between a GeForce 2 MX/MX400, you still need to make sure that you are, in fact, buying a REAL GeForce 2 MX/MX400. There are A LOT of OEM so called "MX400" cards out there, that have a 64 bit memory bus (which is typical of MX200), instead of the standard 128 bit bus.

pentiumspeed wrote on 2021-05-02, 18:10:

I know how to tell by 128bit memory by looking at chips and I do know that MX does comes in 128bit as well.

How would you tell?

Actually I bought a mx400 by getting a well known model (ABIT T400), reviewed by hardware sites. It overclocks quite well, I am quite happy with the board. On a slower P3 (600 MHz) the mx400 is faster in DX7/8 compared to FX5700 (with 66.xx drivers).

Also MX400 comes in 64bit DDR as well but bandwidth is also bit higher, 3.2GB/s vs 2.656GB/s. Takes proper utility to report this.

Which resolution in situations when memory bandwidth becomes starved? Will a MX400 DDR still memory bandwidth starved?

Cheers,

I am using 3dmark 2000 as a benchmark tool, on a P3 600, with W98SE. In DX7, a GF2MX400 (64MB SDRAM 128 bit bus Interface running at 166MHz) is just as fast as an FX5700 with DDR memory, running at 275MHz.

pentiumspeed wrote on 2021-05-02, 19:20:

Also MX400 comes in 64bit DDR as well but bandwidth is also bit higher, 3.2GB/s vs 2.656GB/s. Takes proper utility to report this.

Which resolution in situations when memory bandwidth becomes starved? Will a MX400 DDR still memory bandwidth starved?

Cheers,

Never had a 64bit DDR version of the GeForce 2 MX400 cards, but from what I heard they are actually a bit slower than the 128 bit SDRAM versions (due to extra latency).
Either way, yes, 64bit DDR basically gives you an identical memory bandwidth to 128 bit SDRAM: 2.6 GB/s.

The memory bandwidth bottleneck affects most games and resolutions (particularly 800 x 600 and above). This can easily be observed through overclocking: if you overclock the core, there will be very little benefit, however, when increasing the memory clock, performance scales nicely.

You could use the date codes on the RAM chips as a clue.
I don't know exactly what date range you'd see on MX400 cards vs original MX - but the later the dates the more likely it's an MX400.
Stay away from anything showing year 2000 dates. I'm not sure how far into 2001 the MX400 came out, but I doubt anything with parts from 2000 was sold as an MX400.

Once the MX400 got introduced it set a new branding scheme (MX200/MX400) and made the original "MX" branding obsolete. Further, I bet the cards required no manufacturing changes except a new firmware and maybe exhausting the supply of "175MHz" rated GPUs (if the manufacturer didn't just overclock them).
So with *retail* cards, the overlap between manufacture of original MX cards and MX400 cards is probably not very big. With OEM cards though, who knows. Some of the big clients might not have jumped on the new model.

I'm guessing you could crossflash an MX to an MX400 if it came down to that, and end up with the literal same thing as what was sold under that name.

The most important thing to look for in GF2 MX cards is the speed rating of the memory chips, usually printed on the chips as the last digit, and specified in nanoseconds.
6ns is slower than 5.5ns, and 5ns is even faster. The MX is memory bandwidth bottlenecked, especially when using 32-bit color.
I also have an Abit MX400, but I chose it specifically because of the faster rated memory. By default the mem was clocked a 166mhz, but it easily runs at 200-220mhz.

That lines up with with my research on these about memory by their ns, I do have chart for this, but year I didn't know about. Thanks!

This only applies to DDR for vram.

DDR Clock Real Clock Clock Period
200 MHz 100 MHz 10 ns
266 MHz 133 MHz 7.5 ns
333 MHz 166 MHz 6 ns
400 MHz 200 MHz 5 ns
533 MHz 266 MHz 3.75 ns
666 MHz 333 MHz 3 ns
800 MHz 400 MHz 2.5 ns
1,066 MHz 533 MHz 1.875 ns
1,333 MHz 666 MHz 1.5 ns
1,600 MHz 800 MHz 1.25 ns

Cheers!

Why make tables when the frequency is obviosly 1000 / x ns.

Interestingly if you could find an mx400 DDR card I've often wondered if you had the right tools to swap the memory chips could you make it much faster by putting on later DDR chips rated for 700 or 800 MHz

You would hit memory controller limitations long before those speeds, but it would certainly be interesting to find out how far can she go.

I had same thought too. Replacing original chips with low ns ddr chips and push the MX400's memory clock higher.

Cheers,

I am not sure how different SDR and DDR memory controller is. But I have Asus V7100 Pro with 4ns SDRAM (so rated for 250 MHz) and it could barely get there - so most likely the memory controller limit .