all vmod for all 6800

[Jethro]

If you cant figure out cap mod from my pic then yah just dont need to be performing the mod

Ram would like some more juice im sure but the cap has helped stability probs @ higher ram speeds for sure.

[zadah]

Thank You !

Doesn't MOSFETs always look like that or similar ?
3 legs, black and big.

Under the heatsink, there are 3 tiny BGA styled chips [ grey IIRC and many legs ].
I'm confused now ?

Sorry, Jethro i Had to borrow your good bicture...was it copyrighted

Here picture of all 6800 LE's MOSFETS and their functions.

There is image which explain how VGPU is made in MOSFETS.


Here is simplified diagram of 6800 LEs PWM control + MOSFETS, principle is same in all 6800 series cards, only PWM controlling iC varies... AND i Have Added CAP mod to VGPU in picture.

[firada]

If you cant figure out cap mod from my pic then yah just dont need to be performing the mod

Ram would like some more juice im sure but the cap has helped stability probs @ higher ram speeds for sure.

You said "Ram would like some more juice" what do you mean with this?I did the cap mod like with your pic but with other capacitor!Only with cap,no mosfets or other,but i can't fix the black screen yet.I set the vcore from 1.4v to 1.5v(3d) and 1.1v to 1.5v(2d) the thrl it's default 1.2v!I must to do something else??Thnx!!

[jumanji969]

You said "Ram would like some more juice" what do you mean with this?I did the cap mod like with your pic but with other capacitor!Only with cap,no mosfets or other,but i can't fix the black screen yet.I set the vcore from 1.4v to 1.5v(3d) and 1.1v to 1.5v(2d) the thrl it's default 1.2v!I must to do something else??Thnx!!

More power to the ram.

[vortex240]

The mosfet and vgpu controler cooling is my main concern. What are the maximum temps that these can operate at before failing? I'm talking about the ugate and lgate mosfets of the gpu and the ISL6534.

[zadah]

The mosfet and vgpu controler cooling is my main concern. What are the maximum temps that these can operate at before failing? I'm talking about the ugate and lgate mosfets of the gpu and the ISL6534.

This could help you, it is VGPU LGATE MOSFET temperature Vs Drain Current graph :


It can work in very hight Temps, but Effiency is falling dramatically....

[vortex240]

if it is for these components then this is good news also I imagine ugate will have a similar max temp if not higher btw how do you know this graph is for these components?

also its the ic that worries me the most

[zadah]

if it is for these components then this is good news also I imagine ugate will have a similar max temp if not higher btw how do you know this graph is for these components?

also its the ic that worries me the most

Here is the complete datasheet for VGPU LGATE Mosfet, it can allso be found at www.irf.com:
7832.pdf

And Here is DS for UGATE and LGATE for DDR:
7821.pdf

I dont know type of UGATE VGPU MOSFET , if anyone can help please reply...

I think ISL PWM controller will newer warm too much, because it is just controlling IC.

[Del Gro Badeu]

i've searched for the ugate vgpu mosfet and was unable to find something intereting on google : /

[firada]

More power to the ram.

More power from vbios mod or with a cap???With 1.5v(3d) from bios the temperature is under from 70c!And default volt mod the temp was it 47c!!

[kryptobs2000]

More power from vbios mod or with a cap???With 1.5v(3d) from bios the temperature is under from 70c!And default volt mod the temp was it 47c!!

vcore = voltage for the core
stock 6800 Ultra - 1.4v
stock 6800 GT - 1.3v
stock 6800/le - 1.2?

vddr/vdimm/vmem = voltage for the memory.
stock 6800 ultra/gt - 2.05 (I think)
stock 6800/le - don't know

That capacitor mod helps stabalize the memory voltage, vddr. It has nothing to do with the core voltage. You cannot change the vddr voltage within the bios. Only the vcore voltage. Do you understand what I'm saying?

Your talking about vcore.

[firada]

That capacitor mod helps stabalize the memory voltage, vddr. It has nothing to do with the core voltage. You cannot change the vddr voltage within the bios. Only the vcore voltage. Do you understand what I'm saying?

Your talking about vcore.

I know that,but i readed in other forum that the vcore it's must to be 1.5v(3d&2d)!And i know what is do the capacitor.I don't want to do my card rocket,only to do play's games normal,without black screen!I didn't this yet,but i hope to solve!!!

[Jethro]

good information here! I suppose one should install heatsinks on these mosfets for better voltage stability?

[stealthbomber]

Yes, the copper heatsinks helped in my case but I needed active cooling, the area where all the caps/mosfets are located at the back got rather hot after looping the card for several hours (>7hrs) until eventually it produced small visual glitches due to heat build up.

I adjusted the position of the 92mm fan to make more space and tied a 80mm fan right at the back of the card, passed 10hrs worth of loops before I stopped it.

I'm tempted to add another fan at the back of the card but the hard disk IDE cable hangs over the cards back blocking some of the airflow...

[OnLine]

http://www.kolumbus.fi/ap.salmela/CAPmod.bmp
Sorry, Jethro i Had to borrow your good bicture...was it copyrighted

Here picture of all 6800 LE's MOSFETS and their functions.

There is image which explain how VGPU is made in MOSFETS.


Here is simplified diagram of 6800 LEs PWM control + MOSFETS, principle is same in all 6800 series cards, only PWM controlling iC varies... AND i Have Added CAP mod to VGPU in picture.
http://www.kolumbus.fi/ap.salmela/ISL.JPG

Yeah, just just what I thought !

Nah, actually I'm even more confused now but it seems to me le/nu has far more controller chips than gt/u. My gt doesn't have any of those U/Lgate mosfets showned in your picture, but it does have a big fat chip [ ~40 legs reads VT1103M, probably instead of ISL6534 ] on the backside of the board and 3 bga styled chips [ possibly 100 legs ] underneath that heatsink.

Hm, 117s adj441 [ 3 legs and 2 of them ] ~ don't know, perhaps these are mosfets although it doesn't look like that.

[vortex240]

I measured the temp of the ISL6534 and it gets quite hot. At 1.2 stock nu voltage it peaks at close to 50 C after some hardcore 3d. At 1.4 v its near 85 C. I didnt even wanna try 1.5v seeing how the trend was progressing.

[acdc]

I think the chips under the heatsink are the MOSFETS, because PWM control chip doesnt need any heatsink. If the heatsink is really getting colder, the extra mod can be used without any risk. In this case, PWM control is driving cards own MOSFETs down, beacause of over voltage in sensing line of the PWM control chip ( I am still sure, that every 6800 series card has PWM controlled MOSFETS, because other way is linear regulation, like LM317 in your mod.)

For GT/Ultra it's not clean MOSFETs.
Volterra's VT1xxx series is Multi-Phase (up to six) Synchronous Buck Voltage Regulator Chipset. It's contains master controler chip (VT1103M) and up to six secondary VT1103S - power MOSFETs with integrated drivers.

And Reason for Ultra cards distributing power to two different Memory lines is the fact that you cant use two PWM power supplies in the same power line.

That's right for more PWM, but for Voltera VT2xx series (Single-Phase
Integrated Synchronous Buck Voltage
Regulator Chipset) it's possible - see picture above

[zadah]

I measured the temp of the ISL6534 and it gets quite hot. At 1.2 stock nu voltage it peaks at close to 50 C after some hardcore 3d. At 1.4 v its near 85 C. I didnt even wanna try 1.5v seeing how the trend was progressing.

Ok, i havent measured those temps personally... but sounds bad beacuse max operating temperature is rated 85 C !! I cant realize warming of that controlling IC...

[zadah]

That's right for more PWM, but for Voltera VT2xx series (Single-Phase
Integrated Synchronous Buck Voltage
Regulator Chipset) it's possible - see picture above

OK, i tought GT / Ultras are using regular MOSFETS....

[Jethro]

i felt the IC after some heavy gaming and noticed it gets really hot! ive since backed down to 1.31vgpu and for some reason after burning the GPU in its perfectly fine @ 410 now with much less volts. Now if i can just figure out what the ram wants/needs!

[Del Gro Badeu]

the rams wants/needs to be really hard overclocked

i've starting to mod my card yesterday, but i need to wait for my new wateblock and water pump to test it :/

[Jethro]

went and bought a new 15/30 watt iron, extra tips, tips for my 60watt and a 10k pot.
They didnt have but one of the good 10k pots left! anyways gonna do the mod tonight ill post results.

[Jethro]

ok i soldiered 10k pot to one of the red points and nothing? all i get is black screen when lowering resist? The pot reads voltage fine 2.73. Can someone show me exactly where the ddr vmod is on my card please? im using the lowest red dot and ground so i dunno whats up.

[stealthbomber]

>>>

[Jethro]

well the front page is wrong then cus the lowest red dot doesnt work! thanks stealth ill have to do it again. Is a 10k pot to little? i would like up to 2.9v. According to first page 10 = 2.95! so i read it wrong for shopping today.. what are you using? figures i go thru all the trouble and the one spot i pick to soldier is wrong lol.

At least i didnt FRY the card DOH!