Matrox G400 OVERVOLT?

[Alby3D[ITA]]

this is not a good news for me DGHOST but I know that the difference between AGP 2X 4X 8X is little so I just need a Board with KT266. The good news is that I've found the datasheet (with help of rylan) of the voltage regoulator and Some info about the RAM in my videoboard. Nothing special anyway only simply SAMSUNG SGRAM 166MHz
CL 3 - 2
MAX Volt 3.6V (+0.3 from default)

I have another question about this board : I've heard somewhere that is possibly to clock RAM and CORE with different frequency by a multiply (via registry key) :

Example RAM to 90% of core frequency... do you know something about this?

DGhost you're right the G400 is the last big VGA. I've got even a G200 in the past but the quality with G400 is exxxtreme. Even with my worst pc with an old Olidata screen all is sharp.
Thanks a lot to Rylan and DGHOST

[rylan]

Ahh ok since the SGRAM runs at 3.3v the regulator you found should be for the graphics chip core voltage. I should note that asics generally run on multiple voltages... for example 2.5v core voltage, but the I/O ring will have to be powered at 3.3v to talk to the memory. So if the memory is whats holding back your overclock, pushing 2.5v up won't help.

Not sure on differant frequencies through the registry, since the clocks on the card are controled by a programmable clock synthisizer with certin dividers. If you're using the MGATweak utility then you have pretty much foll control over the clocks and dividers on the board.

[Alby3D[ITA]]

Thanks a lot for your help Rylan. I'm not sure but I think that if RAM and core don't run at the same frequency and there's only one Clock generator the card provide to assign different clock to the component and also you can tune the clock. Do you Understand? I say that the clock generator can be reprogrammed via registry like the core clock with MGATweak util. In this case I can easily overclock the core to 250MHz and if the RAM won't follow at high frequency the core clock I set a divider like 2/3. This is only an example and I won't do this. I wonder if it is possible...

I hope you understand...


For all that need info about the voltage regolator on G400:

http://www.semtech.com/pdf/ez158x.pdf

For everyone interested in G400's SGRAM take a

look http://www.samsung.com/Products/Semi...k4g323222a.pdf]


Do you like my new avatar?

[rylan]

On my G400MAX the core and memory run at differant speeds due to a differant clock synthizer divider. Yes I believe there is one clock synthizer that generates the clocks for the memory and graphics core but with differant outputs. I'll have to get my other system with my MAX running again, since I'm in the process of switching it over to WinXP for a hom theater pc.

[Alby3D[ITA]]

I totally agree with you Rylan. Even the non max card have different clock RAM - GPU. My final target is to test G400 with 3D mark 2001. I know that G400 is Dx6 card but this is the only way to compare results. At this porpouse..... Is it possibly to emule the T&L with program like 3D analyzer to bench it?
This is a trick (cheat) for a bench but in this case I can run several test that need Dx 8.1 or T&L.

Yesterday I take a look at the board and I removed the "spring" that hold the sink down and: surprise.... the sink didn't move.
There must be some epox glue on the chip surface.
I've just put the board in the freezer.....

[Greebe]

That's because all G400's have a PLL to divide the frequencies between the gpu and mem. The only thing that diferentiate a Max from the others is the clockspeed.

The HS is held on with a thermal wax. the purpose of the spring is so the HS when new contacts the gpu properly as it's required to heat the TW and make an even bond between the two.

Don't forget todo the R68 mod while you are at it.

[Wombat]

Originally posted by Greebe
That's because all G400's have a PLL to divide the frequencies between the gpu and mem. The only thing that diferentiate a Max from the others is the clockspeed.

And the RAMDAC, but it probably won't be an issue.

[rylan]

Yeah the ramdac is dynamically programmable and its speed should only depend on the display resolution and frequency. I don't think he plans on trying to run the card at 2048x1536@100Hz

[kjliew]

If I still remember correctly from my vague memory while developing MGATweak, there is a way to lock the memory clock by selecting different clock source for memory clock. In that case, the PLL only clock the GPU core clock, GCLK, while the memory clock, MCLK is bypassed using bus clock. That will be 33MHz if it's a PCI card, and 66MHz if it's an AGP.

However, I don't think you can achieve optimum performance with such configuration, since MCLK is a very crucial performance factor. With G400, which is an pre-DirectX7 GPU, fillrate is a big thing, not the polygon count. Hindering MCLK will seriously reduce the fillrate, and any improvement in GCLK is useless.

[Alby3D[ITA]]

Yeah Greebe:

the termal paste is a glue too. (Sorry for bad english) Now I understand that will be an hard question to remove the sink from GPU. I put the card in the freezer then I try to remove it but... nothing nor with a clamp I removed it.
With a screw driver I'll damage the board so i'll try with a "razor blade but it is quite difficoult because the sink is big verrrry big. Bigger than the GPU.
I won't do the R68 mod because I'll test the board in a Asus A7V133 A or in a Soyo K7V Dragon plus Kt 266. None of them are AGP 8X. In any case is there any photo about the mod ? I couldn't find on web.
Listen here: I don't think that mo-bo with AGP 8X will burn if you try an AGP 2X board, yesterday I installed on my Epox 8RDA3+ (Nforce 2 Ultra) my old Kyro 2 (AGP 2X). I didn't remember that the VGA is only 2X AGP. The screen fliker and I've got serious artifacts during some tests. I thought that the board had burnt (or damaged) but after a little search on web I had the answer: AGP 2X. I removed the VGA reinstall my Geforce and everything OK.

For WOMBAT and RYLAN
I had loved the G400 at high frequency on my screen
for example: 1920*1440 @ 92 Hz. This board work with all res. at all freq. Incredibly!!!
The difference with this board is in graphic apps. When you design a trasparent solid (like a cube) in 3D Studio MAX the openGL driver display grey cube with some dark dot over the entire surface.
With my Gainward Ti 4200 the cube during a pan operation or a zoom op. seems to flick even @ 100 Hz. With G400 colours and transparent solid seems sharper and more brilliant. Anyway the G400 had serious bug with 3D studio.
About the GPU what do you think even the graphic core runs ad 3.3 V I think 2.5 V can be enough for a 0.25 micron process....

For
Kjliew
About"If I still remember correctly from my vague memory while developing MGATweak, there is a way to lock the memory clock by selecting different clock source for memory clock. In that case, the PLL only clock the GPU core clock, GCLK, while the memory clock, MCLK is bypassed using bus clock. That will be 33MHz if it's a PCI card, and 66MHz if it's an AGP."

When i'll start my overclock I'll serch into register of win if there is something that concerns RAM clock and GPU clock.
Maybe I'll install 2 clock generator on the board.

[COLOR=skyblue][COLOR=skyblue][COLOR=skyblue]

[Greebe]

It's a thermal wax (like in candle) not glue... nor is heatsink compound glue

To remove, you must heat the HS up to at least 70c

[rylan]

Use a hairdrier on the heatsink. That should soften the goop enough to pull the heatsink off. Be careful not to burn your fingers

[Alby3D[ITA]]

even not to burn the board![FONT=arial][FONT=arial][FONT=arial]

At 70° the GPU bye bye...

[Wombat]

Originally posted by Alby3D[ITA]
even not to burn the board![FONT=arial][FONT=arial][FONT=arial]

At 70° the GPU bye bye...

No, Greebe knows what he's talking about.

[Alby3D[ITA]]

Sorry that would be a joke... anyway it works.
This afternoon i had removed the sink with an hairdrier.
Now I'm writing with my Pentium 3 500 and a G400
Thanks Greebe & Rylan.

Stay tuned I'm going to do preliminar tests.

HERE my system:

Pentium 3 Katmai 512kb cache 500MHz @ 525MHz
Mobo Soyo P3B
192MB SDRAM
MATROX G400 Default freq.
HDD 20 GB 7200 rpm

This is my first result
ATTENTION the system is
******Not Formatted********
3D Mark 2001 --------------> 830 marks