thanks for the good advice!Quote:
Originally Posted by SikaRippa
could you indicate the points on the capacitors where to solder additional capactiro for Vgpu
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thanks for the good advice!Quote:
Originally Posted by SikaRippa
could you indicate the points on the capacitors where to solder additional capactiro for Vgpu
Absolute maximum ratings for memory chips is 2.95 V according to datasheet.Quote:
Originally Posted by ya_master
Anything above that probably shorten the life of the chips.
--
You do not need to read whole thread to get idea about cap mods. Here is very short version:
- In the case of 'black screen' affected GF6800LE-card the stability of the card can be greatly enhanced with several different 'capacitor mods' (see BS-document, different thread)
- Memory and core OC'ing can be enhanced in some extent (with some cards) if a VERY good capacitor(s) is added to Vmem or/and Vcore nodes
- Optimal point for Vmem capacitor is between TP10 (+) TP9 (-), not TP1 as explained in some guides
- Optimal point for Vcore capacitor is: +node directly to the core capacitors (1500uf/2.5V) + node. See figure below:
http://img418.imageshack.us/img418/4...ints5ge.th.jpg
See above..Quote:
Originally Posted by ***Deimos***
mmhmm
i did the vmem cap mod with TP1 and ground. i will change that to TP10 and TP9.
yes i have read about max 2.95v in the datasheet, too. thats the officiall version.
but usually hardware is designed to last for how long? 10 years? if 3.xxV decreases the lifetime from 10 years to 8 years i'm willing to take that risk. in 8 years this gfx card isn't worth its own weight in sh*t anyway. :D
the usual 10% increase of voltage without much danger would mean ~3.25v. sounds tough. maybe i will try 3.05v - 3.10v and see how far i can get the mem. but first i need to redo the cap mod for mem. maybe that will improve something too.
Try it and let us know if it works good :DQuote:
Originally Posted by ya_master
Sorry for the double post.
How come I get no artifacts in ATITool, no artifacts in 3dmark(no matter which version), I get no artifacts in BF2..
But when I watch a divx video, or TV tuner, I get some small lil dots that are barely noticable every once and a while..
Little red looking dots..
WTF lol..
mem ist running now at 3.08V and 980mhz seem to work fine. i think i will increase voltage to 3.15V and hope i get beyond 1ghz.
but not more than 3.15V. i don't want to run out of luck. :D
and i added little heatsinks to one litte mosfet and 2 strange silver boxes (i don't know the english word, these things working with 'henry'). especially the big silver one was getting really hot. maybe something is getting better with that heatsink applied.
and i still need to redo the cap mod. don't have much time. :(
I had that too. Its probably from my memory, because it happens when I forgetfully leave it at 950Mhz (or higher). I am really eager to try replacing onboard capacitors with some Chemi-con PXA... will try to stop by one of those electronics parts stores tomorrow. Yesterday went to Radio Shack.. they understood "capacitor", but I completely lost them when I started talking about ripple current, and tangent angle... lol.. best they could provide was a little baggie of assorted capacitors.. no thanks.Quote:
Originally Posted by bigboi86
looks like you are taking proper precautionary measures against heat... if you can, take a picture of how you put heatsinks on the little ICs on the back of the card.. my card is slightly different than what's shown in most 6800 snapshots.. so I got little copper spacers and a green chipset heatsink... looks pretty spiffy. It blends in so well, I could probably RMA with it on ;)Quote:
Originally Posted by ya_master
EDIT: those silver/gray things on the front side of the card between the tall SMT capacitors?
Let me know if putting higher quality capacitors on it helps any.Quote:
Originally Posted by ***Deimos***
I guess I really need some more voltage, should I try 2k ohm fixed resistor instead of 2.2k, less resistance means more voltage right?
Also, radioshack is quite useless unless you need a cheap DMM, basic soldering/wiring accessories, or batteries IMO.
I used to work there ;)
Hey just curious. Those bottom 3-4 IC in the corner. On your card, are two of them lower profile, and with only 4 legs on one side.. ie not the 4 legs on either side type?Quote:
Originally Posted by bigboi86
Since you dont have better capacitors than me, perhaps you have better MOSFETS.
(after adding/replacing capacitors, the MOSFETS will be my next target.. after that.. who knows.. probably the feedback compensation circuitry or whatever else.. an oscilliscope would be pretty useful about now -_-)
http://www.datasheetcatalog.com/data.../IRF7832.shtml
http://www.datasheetcatalog.com/data.../IRF7821.shtml
both power nMOS in SO-8.
But, I have a "2168 4U4" at Q504 (where most folks in their pics have a 7832, even though the top solder pads for the gate are all joined).
I think this is it:
http://www.datasheetcatalog.com/data...HAT2168H.shtml
Very good capacitors e.g Chemi-cons PXA's or Sanyo SVP's can be found ONLY from professional suppliers e.g. Digi-key (PXA's) or Farnell (SVP's).Quote:
Originally Posted by ***Deimos***
That could be true, because sooo many MOSFET's have been burn in these cards. Therefore, it is possible that manufacturers are using different (better, smaller Ron?) MOSFET's.Quote:
Since you dont have better capacitors than me, perhaps you have better MOSFETS.
You have already read that part of BS-document considering feedback modification (?) That was tested by 'zxcv' and he got quite impressive results.Quote:
(after adding/replacing capacitors, the MOSFETS will be my next target.. after that.. who knows.. probably the feedback compensation circuitry or whatever else.. an oscilliscope would be pretty useful about now -_-)
I have also dreaming to get (build?) an oscillosscope.. I have heard bitscope-devices are quite good in many purposes if you do not need gigahertz operation...
--
EDIT: In GW6800le-cards all those MOSFET's are exactly the same models as you listed, but e.g. in (some/all?) MSI6800le-cards there is 8 pin power MOSFET instead of "2168". I have a foto of MSI-card and I suppose the code is IRF 7821 i.e. the same model as used usually for memory part !!
Yes, but unlike everyone else I have two (2) 2168. And, as shown in the datasheets, they have many different parameters, including Ron, Qc, current, and temperature de-rating.
As far as parameters are *better* or at least tolerable there are several options for replacement. I investigated some times ago which component would be good replacement for IRF7821 and found this:Quote:
Originally Posted by ***Deimos***
http://www.st.com/stonline/products/...sts12nf30l.htm
Good news are that this MOSFET can be found quite easily and Ron is smaller, which would have really positive impact to temperature. BTW this component was tested successfully by Finnish user having one IRF7821 burn.
The reason I registered in this forum is your article and that I wanted to thank you for taking so much time in it. I have an MSI 6800 TD128 (AGP) with the problematic caps (4 8 479 6E). I hadn't read your thread yet and overclocked it @375/800. I had an NV Silencer v5 on it and everything seemed ok. Had run some 3dmarks (2001,2003 and 2005) on it and everything looked perfectly stable on it. Then after about one hour in Warcraft 3 I heard a tsaf (like when a fuse is blown) and I got a BS static noise and smell like of burned component. I powered off imediately and after 2-3 mins repowered on. Everything seemed to work normally except the fact that the temperature was slowly rising and reached 65C before I turned my pc off. I checked the card to find out that it gave no power to the cooler fan of the Silencer. I tried another fan (the stock) to verify that. Then I started searching your internet about problems with the MSI 6800 and fell upon your thread. Luckily I can RMA it so I won't try your mods right now although I would really like to do so. If the card was giving power to the fan I might have tried the replacement of the caps. Well I'll see what I receive from the RMA and maybe I'll have to do it with my next card. Great work my friend...
Its certainly a good thing you are still covered under warranty. Unfortunately, I wasnt always that lucky. A TNT2 Ultra I had, got so hot in one section of the PCB, it darkned the PCB. On a GF4, some FETS got chared and some capacitors litterally blew up. A short circuit in a 9800pro volt mod, litterally produced fireworks like from a "sparkler".. first thing I did after yanking the power bar, was run for the fire extinguisher.Quote:
Originally Posted by FoRMat MaSTer
This 6800 of mine.. its built like a tank.. Considering all the abuse I've put it through, it should have died many times over. Many times it seemed dead, but somehow managed to spring back to life. Just recently I left 3DMark2001 looping... the fan I use to blow at the back of the card at my custom heatsink on the voltage regulators, got some cable stuck in it.. as you can imagine, by the time I came back, things got pretty hot.
As for doing the capacitor mod, you should only do that if your warranty is already over, and/or things are so bad, you've got nothing to lose. Even if it works at "just" 850, I would gladly leave it be.
hi guys this is great thread but too long to read though to find what i need to know and the search function cant find anything.
iv got a XFX 6800 GT AGP, i just want to up the GPU and MEM volts a tad to get at most 450/1200. the card will be cooled by water. im just a tad lost at the mo.
Hi,Quote:
Originally Posted by FoRMat MaSTer
As ***Deimos*** already said the best solution is of course RMA.
Some users have posted that power MOSFET's at back side of the card have been burn after Vmodding of GPU. However, in this case (=your card is still working) it is not possible that MOSFET's have been burn. Quite curious to get 'fuse flown effect' in VGA and still working !
For GPU best/easiest way is bios.Quote:
Originally Posted by burnout21
For Vmem take a look this much shorter thread (an easier way to perform mod that in the post #1, there are also some comments about Vmod for GPU):
http://www.xtremesystems.org/forums/...ight=easy+vmem
cann you tell me how to mod a bios
have you tried google?
unless you are comfortable with hex editors, a good place to start would be NIBITOR from mkvtech
Hey I'm running the 2.2k ohm resistor between TP13 and TP14.
Should I lower it to ~2k ohms for a lil more voltage?
I have no DMM btw :toast:
without the possibility to measure the exact voltage you shouldn't do anything. just a suicide mission.Quote:
Originally Posted by bigboi86
Yeah, lol.Quote:
Originally Posted by ya_master
2.2k ohm is safe though, would 2k ohm be drastically different voltage?
The difference of 200 ohm should not have dramatic consequences. However, as can be seen in the guide the voltage increases 'exponentially' when added resistor value decreases. Therefore is good to have:Quote:
Originally Posted by bigboi86
1. Fixed resistor in series to avoid short in any case
2. Multimeter always on hand for measuring resistance values BEFORE soldering and voltage levels BEFORE & AFTER mod
Quote:
Originally Posted by SikaRippa
I guess I'll just stick it out 'til my first paycheck, and buy the DMM and stuff.
Overclocking is so addicting I'd rather risk frying my stuff instead of waiting sometimes. :rolleyes: